text:
Behavioural responses to heat in desert birds: implications for predicting vulnerability to climate warming
B. Smit1,
G. Zietsman2,
R. O. Martin2,
S. J. Cunningham2,
A. E. McKechnie3 &
P. A. R. Hockey2
Temperature increases associated with climate change pose a substantial threat to arid-zone bird species. However, predicting vulnerability to high temperatures using species-specific, mechanistic data, and assessing how this varies within and among species, is complex, time consuming and expensive. Using the bird community of the southern Kalahari Desert, we investigated whether interspecific variation in heat dissipation behaviour (HDB) thresholds could provide an index of vulnerability to high temperatures. We fitted logistic regression models to presence/absence data for behaviours as a function of air temperature (T air) in order to determine, for each species, the T air at which panting and gular flutter (pant 50), wing-drooping (wing 50), resting (rest 50) and shade-seeking (shade 50) responses occurred in 50 % of instances.
We show that pant 50 (n = 30 species) is higher in species that 1) are smaller, 2) maintain low activity levels at high T airs, and 3) rely mostly on food as their water source (i.e. non-drinking species) — the only predictor variable to remain significant in phylogenetically-independent analyses. Like pant 50, wing 50 (n = 30 species) was negatively correlated with body mass, but did not vary systematically with other organismal traits. There was no systematic variation in shade 50 (n = 33 species) or rest 50 (n = 14 species) values.
Our findings suggest that evaporative cooling demands are relatively higher in larger birds and could limit activities (such as foraging) at T airs exceeding 30 °C, while the trade-off between thermoregulation and sustaining activity levels appears less pronounced in smaller species. Kalahari species that do not drink regularly show a relatively greater dependence on wing-drooping compared to panting/gular flutter, probably resulting from selective pressures to reduce evaporative cooling demands in an arid environment with scarce surface water. Two key questions remain to be answered to confirm whether variation in HDB thresholds provides an opportunity for rapid assessment of vulnerability to high temperatures in avian species from hot, arid environments. First, what are the relationships between HDB patterns and body temperature regulation? Second, is heat dissipation effort indicative of dehydration risk?
A key challenge facing researchers seeking to predict the impacts of climate change on animals concerns the trade-off between single-species models based on in-depth studies of physiological and behavioural processes, versus more generalised correlative models that can yield predictions for entire communities. Recent decades have seen substantial conceptual development in both these fields. Bioclimatic envelope models (BEMs) have rapidly become a popular prediction tool for large scale changes in the distributions of organisms in response to climate warming [1–4]. BEMs rely on quantifying the climate envelope currently inhabited by a species, then using outputs from global circulation models to predict where, geographically, suitable climate conditions for the species will occur in future. The attractiveness of this method and its popularity over the last two decades [1, 5, 6] is due in no small measure to the relative ease and rapidity with which predictions for multiple species can be generated.
In contrast to BEMs, mechanistic models predict species' niches based on detailed understanding of ecological and physiological processes. Detailed parameterisation of mechanistic models relies on intensive and time-consuming sampling of focal taxa. To date, this approach has focussed predominantly on single species [7–10], limiting inference over the potential impact of climate change on communities. Despite the difficulties of building and parameterising complete mechanistic models, empirical mechanistic studies have provided convincing insights into how particular species and populations are affected by climate, particularly in response to high temperatures (e.g., [11–19]).
Birds inhabiting hot, arid environments provide a useful model system for developing novel approaches to predicting species' vulnerabilities to increasing temperatures, combining mechanistic underpinnings with the potential to rapidly and cheaply generate predictions for entire communities. In these habitats, operative temperatures (a measure of the overall environmental heat load experienced by an animal [20]) routinely approach or exceed avian body temperature (T b) [21]. This creates conditions where the need to conserve water and avoid dehydration is in direct conflict with reliance on evaporative cooling to avoid lethal hyperthermia [17, 22–25]. Occasionally, periods of extremely hot weather cause catastrophic mass mortality events, sometimes involving thousands of individuals [26, 27]. Even at air temperature (T air) below avian T b, metabolic heat gain, or heat gained from solar radiation, means that birds must frequently dissipate excess heat via evaporative and non-evaporative mechanisms, such as panting/gular flutter and wing-drooping, respectively [14, 28–30]. The demands of heat dissipation behaviour (HDB) can lead to trade-offs that have potentially far-reaching implications for body condition, survival and reproduction [13, 31, 32].
Recent studies in southern Africa's Kalahari Desert highlight the links between easily-observable patterns of behaviour and variables that directly impact survival and reproduction [13–16, 31]. For example, du Plessis et al. [13], found a negative correlation between T air and body mass (M b) gain of Southern Pied Babblers (Turdoides bicolour) during summer, such that on hot days (i.e. maximum T air > 35.5 °C) the birds' M b gain during the day was insufficient to balance typical overnight M b loss. Reduced M b gain appeared to be driven by reduced foraging efficiency on hot days resulting from conflicts between dissipating heat by panting and simultaneous foraging [13].
Relatively little is known about the effects of high T air on behavioural and physiological responses in free-ranging birds [13, 14, 16, 33], and more specifically, how these vary at an inter-specific level with organismal variables such as M b and ecological attributes (e.g. behaviour, diet and microhabitat use) [34]. Although we expect the time allocated to heat dissipation to increase at high T air, we can also make several predictions regarding interspecific variation in HDB.
First, larger birds have been shown to initiate evaporative cooling responses at lower temperatures compared to smaller birds [35], presumably reflecting their lower surface area-volume ratios and increasing thermal inertia with increasing M b. Hence, we might predict that during hot weather, trade-offs between HDB and time allocated to activities, such as foraging and maintenance behaviours, should be more pronounced in larger species.
Second, we expect that the ecological significance of such trade-offs is greater in species with overall higher activity levels. For example, species that are active gleaners, and whose foraging mode involves near-constant activity, presumably generate a greater metabolic heat load per unit time while foraging, compared to sit-and-wait foragers.
Third, respiratory HDB, in particular panting and gular flutter, is associated with high evaporative water loss (EWL) requirements. We may therefore expect species relying solely on food as a water source to depend to a lesser extent on respiratory EWL and more on passive heat loss mechanisms such as wing-drooping. These species may also show lower activity levels and spend less time in the sun to reduce evaporative cooling demands.
We test whether HDB varies in a predictable manner among bird species from the southern Kalahari. Should HDB thresholds vary predictably (as outlined above), then we believe behaviour is likely to be both a good proxy for investigating the ecological significance of thermal physiological trade-offs, and useful in understanding ecological and evolutionary determinants of species persistence in hot, arid landscapes.
Study sites
Data were collected at three different sites within the southern Kalahari: Tswalu Kalahari Reserve (S27°19′, E22°25′), Dreghorn Game Ranch (S26°52′, E20°43′) and Kuruman River Reserve (S26°58′, E21°49′). All sites were located within the arid savannah biome of the Northern Cape Province of South Africa. Mean annual rainfall data values were obtained from private rangeland owners. At Tswalu Kalahari Reserve, mean annual rainfall over a 30-year period was 295 ± 172 mm (coefficient of variation, CV = 58.3 %) (D.N. MacFadyen, unpublished data). Mean annual rainfall at a ranch near Kuruman River Reserve and Dreghorn Game Ranch was lower at ~190 ± 125 mm (CV = 66 %) over a 60-year period (G. Scholtz, unpublished data). Long-term T air data were not available for these sites. Habitat type at all three study sites was savannah on red sand dunes with no natural free-standing surface water sources, although there were artificial water troughs in the reserves/ranches.
During our study we obtained weather data using a portable weather station (Vantage Pro2, Davis Instruments, Hayward, CA), set 2 m above the ground at a central location within each study site. The T air recorded during our study ranged from 18.9 to 38.9 °C (record maximum T air was 37–38.9 °C at all the sites during the study).
Behavioural observations
Behavioural observations of birds were conducted during austral summers (November-March) of 2009/2010 and 2010/2011. We collected a total of 11,110 observations during the study at all the sites; 4673 observations at Tswalu Kalahari Reserve during the first summer, and 4243 during the second. We also collected 2148 observations at Dreghorn Game Ranch and 62 at Kuruman River Reserve during the second summer. The small numbers of observations from Kuruman River Reserve were included to boost observations for a few target species (e.g. Crimson-breasted Shrike, Laniarius atrococcineus). Behavioural observations were conducted during the warmer part of the day (between 10:00 h and 18:00 h) when bird behaviour was likely to be affected most by high temperatures. We conducted observations by searching for birds while walking, or from a vehicle. Walking observations were conducted in 426 plots (approximately 800 m × 100 m in size) that we selected at random within the landscape. These plots were separated by at least 500 m, and were a minimum of 500 m from the nearest surface water source. The majority of the plots were sampled only once (414 plots, 3545 observations), and plots sampled on the same day were always more than 1 km apart. A subset of 12 plots at Tswalu Kalahari Reserve were surveyed 18 times each, at varying times of day and on days of varying maximum air temperature (total of 5546 observations); during repeated sampling of these plots there may have been some degree of pseudoreplication as some individual birds may have been observed more than once. Within each plot, we searched for birds over a period of 30 min to 1 h by moving from one end to the other at an average speed of ~0.5 kmh−1 stopping regularly to scan the surroundings for birds. Driving observations were obtained ad-hoc while driving in a motor vehicle along an un-surfaced track (a total of 235 tracks, 2019 observations) between 1 and 10 kmh−1 for 30 min to 1 h; each track was only sampled once. We stopped the motor vehicle at regular intervals and scanned for birds; birds were generally more conspicuous when approached from the vehicle than by foot.
During observation periods, each bird seen was identified to species level, and we recorded the presence (=1) or absence (=0) of HDB; if HDB could not be assessed = NA (Not Applicable). Heat dissipation behaviours were categorised as either respiratory HDB, or non-respiratory HDB. Panting (defined as gaping when breathing) and gular flutter (rapid movement of the gular area) behaviours are well known avian respiratory HDBs associated directly with evaporative cooling and increased EWL rates [23, 28–30, 36, 37]. Wing-drooping behaviour (defined as holding the wings away from the body) is often recorded as a mechanism to increase the surface area of the body to enhance radiative and convective dry heat loss by exposing thermal windows under the wing [28, 37]. Both these categories of behaviours are easily observable in the field [13, 14, 31]. In addition we recorded activity state (mobile = 1, resting = 0) and exposure (full sun = 1, associated with vegetation shade = 0) during the observation event. Behavioural assessment of each individual generally lasted around 30 s.
With the exception of ambush flights (sallying or pouncing), birds in flight were not recorded, and aerial foragers, such as swifts and swallows, were therefore excluded from the study. In addition, birds were not recorded if their behaviour appeared to have been altered by the presence of the observer, or if the bird was observable for too short a time for behaviours to be determined with certainty. If more than one individual of the same species was encountered and it was considered that the behaviour of each individual was not independent of the other birds in the group (e.g. they were foraging together as a flock) then a judgement of the predominant behaviour of the group was made.
Analysis of heat dissipation behaviour
We calculated two types of indices for heat dissipation behaviour:
We determined the relationships between T air and binomial behaviour data for each species separately by performing logistic regression analyses, using a logit link-function and quasi-binomial probability density function to account for over-dispersion, in R [38]. In cases where the beta estimate was significant at the 95 % confidence level, or approached significance (i.e. fell between 95 and 90 % confidence level), we used model predictions to determine, for each species, the T air at which the behavioural response was present in 50 % of observations, i.e. median T air. Median T air values of panting and gular flutter (pant 50), wing-drooping (wing 50), resting (rest 50) and shade-seeking (shade 50) were calculated as the intercept value (absolute) divided by the beta value (absolute).
For each species we extracted all the data recorded at hot T airs (35–40 °C) during our study. We then counted all the instances where each species was panting, wing-drooping, mobile, and in full sun, and calculated proportional values from the total number of observations at hot temperatures for each species; hereafter referred to as prop_pant, prop_wing, prop_act, and prop_sun, respectively. These proportional values provided us with a supplementary index of behaviour in each species.
Previous studies have found a link between humidity, heat load and the demands for evaporative cooling in birds [14, 39]. Specifically, Smit et al. [14] found that White-browed Sparrow-Weavers had higher T bs when vapour pressure deficits were below 2 kPa. During the current study, vapour pressure deficits were sometimes below 2 kPa during rainy periods. Observations associated with vapour pressure deficits below 2 kPa made up a very small proportion of our data, and prevented us from conducting adequate statistical analyses to account for humidity. Excluding data associated with low vapour pressure deficits (<1kPa, <2 kPa, <3 kPa, in a step-wise manner) did not affect our pant 50 estimates. We therefore included all observations in this study, regardless of vapour pressure deficit and did not include humidity as a variable in our analyses.
Interspecific analyses
We performed both generalized linear models (GLS) and phylogenetic generalized linear models (PGLS) in R—the latter using the ape [40] and caper [41] packages, to test for systematic differences in median Tair values of behaviour (pant 50, wing 50, shade 50 and rest 50). In PGLS analyses we used Kappa transformations to estimate phylogenetic signal in the null models for each dependent factor. We included log10 body mass (log10 M b), diet, foraging location, drinking dependency, prop_act, and prop_sun (defined above) as independent variables in the global models (prop_act and prop_sun were excluded from rest 50 and shade 50 models, respectively). Foraging location was grouped into arboreal versus terrestrial foragers; diet was grouped into frugivores, granivores, omnivores and insectivores (insectivores and carnivores pooled); and drinking dependency was grouped into non-drinking or drinking species based on their reliance on free-standing surface water. All above groupings were based on Hockey et al. [42]. We included prop_act and prop_sun as independent variables since we expected high levels of activity and sun exposure to be associated with heat dissipation behaviours.
We sampled 100 phylogenies for all the species in our dataset from http://www.birdtree.org [43] using the Hackett et al. [44] phylogeny as a back-bone. We used the majority consensus tree identified using the programme Mesquite [45]. For each dependant variable we initially ran a global model with all the independent variables as listed above. We then used multi-model inference [46], using the R package "MuMIn" [47] to select the top three models. We based our model selection on Akaike Information Criteria corrected for small sample sizes (AICc) values. We calculated the variance inflation factors for all independent factors in the global models. Although variance inflation factors were never >5, we found that log10 M b and prop_act were correlated (Pearson's correlation coefficient = 0.72). We therefore tested the effect of log10 M b on prop_act using both GLS and PGLS. In these analyses we performed a logit-transformation on prop_act values, following Warton and Hui [48]. In addition, "diet" was slightly collinear with drinking dependency (variance inflation factor = 4) and was subsequently excluded from most global models.
To test our hypothesis that non-drinkers avoid evaporative cooling to conserve water, we calculated the differences between pant 50 and wing 50 (wing 50 – pant 50) values for 17 species and tested if the magnitude and direction of wing 50 – pant 50 differences were explained by drinking dependency, including log10 M b and prop_act as covariates in GLS and PGLS analyses.
We obtained data from 76 species during the study (see Additional file 1: Table S1 and Additional file 2), and were able to calculate statistically significant estimates of median T air values for pant 50, wing 50 and shade 50 for 33 species, and rest 50 values for 13 species (see Additional file 1: Table S2 and Additional file 3). Kappa values in pant 50 and shade 50 were 1.00 and 0.762, respectively, but only approached significance from zero (p = 0.064 and p = 0.051, respectively). The Kappa value of wing 50 was not significantly different from zero (K = 0.571, p = 0.196). Our sample size for rest 50 values was smaller than the minimum number of species needed to obtain a phylogenetic signal [49]. In contrast, we found significant phylogenetic signals in prop_act (K = 0.843, p < 0.01), and log10 M b (K = 0.673, p < 0.05).
Median T air values for different categories of HDB varied widely: pant 50 values ranged from 31.3 to 46.0 °C (mean 39.3 °C), whereas wing 50 values ranged from 35.3 to 44.6 °C (38.9 °C) (Figs. 1 and 2). For 19 species, we were able to obtain estimates of both pant 50 and wing 50 (Fig. 2.). For a further six species, we found a significant response in only wing 50, but not pant 50, and vice versa for another six (Additional file 1: Table S2; Fig. 2). We found that rest 50 and shade 50 values were generally lower than pant 50 and wing 50, and ranged from 6.7 to 38 °C (mean = 24.6 °C) in rest 50, and 14.2 to 54 °C (30.3 °C) in shade 50 (Fig. 3).
Heat dissipation behaviour representing presence/absence of (a & b) panting, and (c & d) wing-drooping as a function of air temperature (T air) in two avian species in the Kalahari Desert; Acacia Pied Barbet, Tricholaema leucomelas (32 g), and Marico Flycatcher, Bradornis mariquensis (26 g). Presence of the behaviour = 1, and absence of the behaviour = 0. The logistic regressions represent predicted proportion of heat dissipation. Significant (p < 0.05) relationships are indicated by solid trendlines. Median T air values where panting (pant 50) or wing-drooping (wing 50) was likely to occur in 50 % of cases are shown in each panel. These species illustrate the variation observed in their heat dissipation responses to T air (see Additional file 1: Table S2, for statistics); whereas Acacia Pied Barbet showed relatively low pant 50 and wing 50 values, Marico Flycather showed relatively high pant 50 and wing 50 values
Median T air values where panting (pant 50, black bars) or wing-drooping (wing 50, white bars) was likely to occur in 50 % of cases in Kalahari Desert bird species
Boxplot summary of median T air values for panting/gular flutter (pant 50), wing-drooping (wing 50), resting (rest 50) and associated with vegetation shade (shade 50) in Kalahari Desert bird species. Number of species for which median T air values were obtained is indicated above each boxplot
We excluded data from Common Ostrich (Struthio camelas, M b > 60 kg) from our multi-species analyses because this species is several orders of magnitude larger than the remaining species from which we obtained HDB data (9 to ~800 g). We also excluded Namaqua Dove (Oena capensis) and Spike-heeled Lark (Chersomanes albofusciata) from pant 50 analyses; Namaqua Dove, Cape Turtle Dove (Streptopelia capicola) and Southern Pale Chanting Goshawk (Melierax canorus) from wing 50; and Ant-eating Chat (Myrmecocichla formicivora) from shade 50 analyses, as their respective median values were highly influential outliers based on Cook's distance.
Models for pant50
A conventional GLS analysis identified log10 M b, prop_act and drinking dependency as important explanatory variables in the top three most highly weighted models of pant 50 (Table 1). We found that pant 50 was significantly negatively correlated with log10 M b t1,25 = −3.62, p < 0.01) and prop_act (t1,25 = −4.05, p < 0.001), and significantly higher in non-drinking species (mean pant 50 ± SD, 40.7 ± 2.6 °C, n = 20) compared to drinking species (36.9 ± 2.4 °C, n = 10) t1,25 = 3.86, p < 0.001) (Fig. 4). Whereas both foraging location and prop_sun were influential in some of the top models, these variables did not show a significant effect on pant 50 (p > 0.1) (Table 1). A PGLS analyses showed that drinking dependency was the most important explanatory variable in all the top weighted models, and non-drinking species had significantly higher pant 50 values compared to drinking species (t1,28 = 3.86, p < 0.001) (Table 1). The top performing model included a positive correlation with prop_sun as an explanatory variable that approached significance (t1,28 = 2.10, p = 0.051).
Table 1 Three top-weighted models explaining median T air values in panting/gular flutter behaviour (pant 50) using both generalized linear models (GLS) and phylogenetic independent analyses (PGLS). The global model included: log10 body mass (log10 M b); proportion of observations where birds were mobile (prop_act), and exposed to full sun (prop_sun) at air temperature between 35 and 40 °C (see methods for details); drinking dependency; foraging location; and diet as independent variables. Only the variables that were influential in the three top-weighted models are shown. For each variable we provide the contrast (± standard error), and significance level (see note below Table)
Median T air values for panting/gular flutter (pant 50) were significantly related to (a) log10 body mass (log10 M b) (negative relationship), b prop_act (negative relationship), and c drinking dependency (D: drinking species; ND: non-drinking species); pant 50 was lower in species that rely on surface water. The insets represent partial residuals of the model including all three above-mentioned variables. The filled and clear circles represent drinking and non-drinking species, respectively
Models for wing50
A conventional GLS showed that log10 M b best explained variation in wing 50 in the top three most influential models (Table 2); wing 50 was significantly negatively correlated with log10 M b (t1,28 = −2.85, p < 0.01; Fig. 5). Although drinking dependency and prop_act were important in models 2 and 3, neither of these had a significant effect on wing 50 (all p > 0.7) (Table 2). In contrast, a PGLS analysis showed that log10 M b and prop_sun were influential in some of the models, but did not perform better than the null model; none of these factors had a significant effect on wing 50 (log 10 M b: p = 0.08; prop_sun: p > 0.30) (Table 2).
Table 2 Three top-weighted models explaining median T air values in wing-drooping behaviour (wing 50) using both generalized linear models (GLS) and phylogenetic independent analyses (PGLS). The global model included: log10 body mass (log10 M b); proportion of observations where birds were mobile (prop_act), and exposed to full sun (prop_sun) at air temperatures between 35 and 40 °C (see methods for details); drinking dependency; foraging location; and diet as independent variables. Only the variables that were influential in the three top weighted models are shown. For each variable we provide the contrast (± standard error), and significance level (see footnote below Table)
Median T air values for wing-drooping (wing 50) varied significantly only with log10 body mass (log10 M b)
Comparing pant50 and wing50
For species for which both pant 50 and wing 50 could be calculated, drinking species showed mean pant 50 and wing 50 values of 37.6 ± 3.7 °C (n = 10) and 39.2 ± 3.4 °C (n = 10), respectively, and these were correlated (Pearson correlation coefficient = 0.752). Non-drinking species showed mean (± SD) pant 50 and wing 50 of 40.7 ± 2.6 °C (n = 18) and 39.2 ± 1.5 °C (n = 18), respectively, and these values were not correlated (Pearson correlation coefficient = 0.244). Both a GLS and PGLS showed that prop_act and drinking dependency significantly predicted the magnitude and direction of wing 50 – pant 50 (Fig. 6). Proportion activity was significantly positively correlated with wing 50 – pant 50 (GLS: t1,25 = 3.33, p < 0.01; PGLS: t1,25 = 2.52, p < 0.05); species with high activity demands showed wing 50 values higher than pant 50 values (Fig. 6). Non-drinking species showed a greater difference between wing 50 and pant 50 values than drinkers (GLS: t1,25 = −3.94, p < 0.001; PGLS: t1,25 = −3.55, p < 0.01); non-drinkers initiated panting at higher T airs than wing-drooping (Fig. 6).
Differential use of wingspreading (wing 50) and panting/gular fluter (pant 50), i.e. wing 50 minus pant50 values, were significantly positively correlated with activity and varied significantly with surface water drinking dependency. Species with low activity demands showed wing 50 values lower than pant 50 values, and non-drinkers showed lower wing 50 than pant 50 values, compared to drinkers. Black dots and clear circles represent drinking and non-drinking species respectively
Models of rest50 and shade 50
Our small sample size of significant rest 50 values precluded detailed interspecific analyses. In both GLS and PGLS analyses, shade 50 was best explained by the null models (see Additional file 1: Table S3). Although prop_act and forage location appeared to be influential in the top three models, none of these were significant (all p > 0.2).
The relationship between prop_act and body mass
Most species were active (mobile) in less than 50 % of the observations (mean prop_act = 0.37), but 11 species were active in more than 50 % of observations (prop_act = 0.5 to 1.0). A GLS showed that prop_act (logit-transformed) was significantly negatively related with log10 M b (GLS: t1,30 = −5.64, p < 0.001); large species were less active (Fig. 7). Similarly, a PGLS analyses revealed that prop_act was significantly negatively correlated with log10 M b (PGLS: t2,30 = −4.17, p < 0.001).
Prop_act varied significantly with log10 body mass (log10 M b). The inset indicates logit-transformed proportion active as a function of log10 M b
We found considerable interspecific variation in the temperature dependency of HDB, activity patterns and shade-seeking among the common bird species of the Kalahari Desert. Most species increased HDB at high temperatures, although reliance on respiratory HDB (i.e., pant 50) versus non-respiratory HDB (wing 50) differed between drinking and non-drinking species. In conventional analyses, respiratory HDB thresholds varied systematically with body mass, activity levels and drinking dependency, while only M b influenced non-respiratory HDB thresholds. After accounting for phylogeny however, drinking dependency was the only remaining variable that explained variation in respiratory HDB. In contrast, after accounting for phylogenetic effects, non-respiratory HDB was not explained by any of the variables in our global analyses.
Importantly, non-drinking species used panting/gular flutter at higher T airs compared to wing-drooping. Birds may face a trade-off between reducing their heat load through evaporative cooling (which requires water) and acquiring this water (an activity that in turn increases heat load or may incur other costs); our data suggest that drinking species afford water-costly HDB at lower a T air threshold, whereas non-drinking species may rely more on passive heat loss to conserve water. To the best of our knowledge, this study is the first to report on interspecific variation in HDB of free-living birds, with previous studies focusing only on single species, for example, Heermann's Gull Larus heermanni [28]; Southern Pied Babbler Turdus bicolor [13]; White-browed Sparrow-Weaver Plocepasser mahali [14]; Common Fiscal Lanius collaris [15]; Australian Magpie Cracticus tibicen [31]; and Great Knots Calidris tenuirostris [50].
Conventional and phylogenetic analyses
Our phylogenetic independent analyses provide strong support for the notion that higher pant 50 values have evolved in non-drinking species. Although log10 M b and prop_act were correlated with most categories of HDB, we found no statistical support for these relationships after taking phylogenetic relatedness into account. Both log10 M b and prop_act showed significant phylogenetic signals, suggesting these traits are phylogenetically constrained. It is therefore not clear whether the effects of log10 M b and prop_act on HDB are the result of mechanistic differences, or simply because closely related taxa are similar in mass and activity patterns. In contrast, the relationship between prop_act and log10 M b was strong, and here the effect remained important after accounting for phylogeny. We believe that the scaling effect of prop_act is linked to the scaling effects of energy-, water-, and heat balance observed in endotherms, regardless of phylogeny. We therefore argue that the correlations of HDB with log10 M b and prop_act that emerged in the conventional analyses are functionally important for understanding how species of varying M b respond to hot conditions.
Effects of body mass and activity levels on heat dissipation behaviour
After accounting for activity levels and drinking dependency in conventional analyses, the negative relationship between pant 50 and log10 M b (albeit limited to species <200 g) observed in our study corroborates laboratory studies of avian thermoregulation at high temperatures. These studies typically show that the T air thresholds for initiation of panting/gular flutter and elevated EWL rates scale negatively with body mass [18, 19, 35, 51]. It was hypothesized that the smaller surface area-volume ratio of larger birds should result in higher thermal inertia, and therefore, as T air approaches T b the windows for passive heat loss become smaller for larger birds compared to small birds [35, 52]. Under these conditions, larger birds will dissipate metabolic heat more slowly via passive avenues, compared to smaller birds, and will either need to store the excess heat (i.e. facultative hyperthermia) or make use of evaporative cooling to minimise hyperthermia. Our pant 50 data, which show that larger birds pant/gular flutter at lower T airs, support the latter point. The former option of storing excess heat in long bouts of hyperthermia has been shown to be less beneficial in large birds, as net water savings are decreased by increased pulmonary water loss at a high T b [53]. We found a significant reduction in activity with increasing T air in 4/7 commonly observed species >100 g (mean 159.1 g). In contrast, only 9/39 species <100 g (mean 64.7 g) showed this same pattern of reduced activity. Reduced activity translates into reduced metabolic heat load, so this finding suggests that larger birds may rely less on facultative hyperthermia and heat storage than smaller birds, perhaps for the above reasons proposed by Tieleman and Williams [53]. More detailed studies on the relationships between M b, hyperthermia and EWL, involving concurrent records of T b patterns and HDB behaviour in birds under natural/semi-natural conditions, will be required to test these hypotheses.
It is important to note that the pattern of lower activity levels and greater heat dissipation effort that we observed in larger birds, which may imply that larger birds are at a disadvantage under climate warming, is likely linked to situations where T air < T b (as was the case in our study). At extremely high T air (T air > T b), when activity is suspended in all birds regardless of M b, a different picture will emerge. Under these conditions, smaller birds, despite regulating T b at higher levels, will still rapidly reach dehydration limits (11 to 20 % of M b) while attempting to maintain T b below lethal limits [51]. Larger birds, on the hand, may be less at risk during extreme heat waves as their lower mass-specific EWL, lower rates of environmental heat gain, and larger body-water pool afford them the critical window of extra survival time.
In our data set, few small species showed significant reductions in activity levels (rest 50 ) at high T air: in total 11 species sustained high levels of activity (prop_act between 0.5 and 1.0) at hot T airs, often while engaging in HDB. Here the relative use of respiratory versus passive heat loss, and degree of facultative hyperthermia used (discussed below) may be critical. Most active behaviour involves foraging, and high foraging effort under hot conditions may indicate strong temperature-related trade-offs [13]. Maintaining high foraging effort is likely important in arid habitats, due to the associated lower overall food availability compared to more mesic habitats [54].
The role of surface water dependency in the initiation of heat dissipation behaviour
The major pattern emerging from our data is that species that are independent of surface water showed higher thresholds for the initiation of panting and gular flutter compared with drinking species. The majority of the drinking species in our study are granivores and most non-drinkers are insectivores. The few non-drinking granivore and omnivore species (e.g. Scaly-feathered Finch Sporopipes squamifrons, and White-browed Sparrow-weaver Plocepasser mahali) also fit the above pattern, with consistently higher pant 50 values compared to granivore and omnivore drinking species (e.g. Cape Sparrow Passer melanurus and Southern Masked Weaver Ploceus velatus). For example, mean pant 50 values were on average 5 °C higher in non-drinking omnivores (40.8 ± 3.8 °C, n = 5) compared to drinking omnivores (35.8 ± 1.9 °C, n = 5).
Our findings also indicate that most non-drinking species depend on wing-drooping behaviour as the dominant form of HDB at T air between 30 and 40 °C, postponing the initiation of panting/gular flutter (to higher T airs). This pattern is consistent among the non-drinkers and suggests behavioural and physiological responses are functionally centred on reducing evaporative water loss. Non-drinking species acquire most of their water by foraging, and therefore run the risk of expending more water on evaporative cooling while active, than they obtain through their food [17, 33, 54], particularly if foraging efficiency is reduced at high T air [13]. Wing-drooping enhances dry heat loss through convective and radiative cooling [28, 37], and while it is unlikely to be as efficient as evaporative cooling, it is less costly in terms of water demands.
We suggest two probable reasons for the link between drinking dependency and high levels of panting and gular flutter. First, drinking species may have more water available than non-drinking species, and consequently are able to expend more water on regulating T b. According to this scenario, we expect the expression of HDB in these species to be very sensitive to reduced water availability; i.e. HDB in drinking species should be reduced when water sources are scarce. For example, when deprived of drinking water, Emus (Dromaius novaehollandiae) reduced respiratory heat dissipation and elevated T b compared to when water was available [55]. However, it is important to note that increased EWL is not the only cost associated with panting and gular flutter: sustained panting carries a risk of alkolosis, i.e. increased build-up of blood CO2 to dangerous levels [56, 57]. Therefore we hypothesize that birds should make use of panting or gular flutter only when the costs of hyperthermia outweigh the physiological costs associated with respiratory HDB. Species with low thresholds for panting or gular flutter might be more sensitive to elevations in T b, which lead to decreases in thermal performance or risk physiological damage [58]. These species will have higher evaporative cooling demands to defend stable T b, which could explain their reliance on drinking water.
We propose that T b patterns at high T air, in particular facultative hyperthermia, play a key role in activity and evaporative cooling trade-offs. Studies relating HDB directly to short-term changes in T b are limited [14]. Smit et al. [14] showed that panting was initiated when T b was above modal active-phase levels in free-ranging White-browed Sparrow-weavers (Plocepasser mahali). Because panting and gular flutter appear to represent a response to increasing T b, potentially approaching lethal limits [44–46 °C, [22]), we hypothesise that variation in thresholds of panting/gular fluttering is related to variation in tolerance of a raised T b. We predict that non-drinking species likely make use of facultative hyperthermia [14] under free-living conditions to a greater extent than drinking species.
Considerations when undertaking this approach
In our study we identified a number of limitations in using heat dissipation and behavioural patterns as a proxy for thermoregulatory demands in bird communities. First, the utility of the method presented here is likely to be limited to relatively open habitat, such as arid regions, where birds can be observed when they are inactive. Second, collecting data at a community level requires that most species are fairly abundant in the community, i.e. species evenness should be high. In many cases workers will need to increase search effort for less abundant species to obtain a community level data set. Third, in cases where a median T air value for HDB cannot be established, an alternative metric for behavioural responses would therefore be to simply use proportional values. In all cases, prop_pant or prop_wing values were highly correlated with their respective median T air values of HDB (see Additional file 1: Figure S1). Median values seem a good predictor of the percentage of time a behaviour is expressed during hot temperatures and represent functional differences in activity time-budgets.
Finally, some avian taxa, such as the order Columbiformes, are expected to make substantial use of cutaneous evaporative cooling [59–61]. Panting or gular flutter behaviour will greatly underestimate evaporative heat dissipation efforts in these taxa. In our study we found that the pant 50 values for two species of dove, Namaqua Dove and Cape Turtle Dove, were higher than for similar sized passerines in our data-set, and represented influential outliers. The low incidence of panting and gular flutter observed in doves could be explained by the highly efficient evaporative cooling rates recently shown for this taxon [62, 63]. In contrast, the order Passeriformes have a limited capacity for cutaneous evaporative cooling at high temperatures [64–66]. We argue that, with the exception of the Columbiformes, cutaneous evaporative cooling is unlikely to be an important avenue of heat loss at high temperatures in most of the species observed in our study, especially the non-drinking species, since cutaneous evaporative cooling will be expensive when water sources are scarce.
Heat dissipation behaviour as a proxy for vulnerability
Many regions in South Africa have shown sustained climate warming over the past few decades, i.e. 1990s to 2010s [67, 68]. Moreover, globally, the years of 2015/2016 have been the warmest on record. During the austral summer of 2015/2016 most of the semi-arid and arid-zone regions of South Africa experienced record monthly maximum temperatures (in some cases 3 to 5 °C above average) and all-time record maxima were observed country wide (https://www.wunderground.com). It seems evident that over the next few decades many avian populations will more frequently experience T airs that will elevate water demands and behavioural trade-offs. Our data show that species vary in their behavioural and thermoregulatory responses to high temperatures. Some of the species included in our study have already been shown to experience challenging trade-offs at T airs between 30 and 40 °C. For example, Common Fiscals (Lanius collaris) show changes in shade-seeking behaviour leading to reduced prey capture and provisioning rates, compromising breeding success [15, 16] and White-browed Sparrow-weavers show elevated T b [14] and mismatches between daily water intake and water loss [17]. Common Fiscals and White-browed Sparrow-weavers have relatively high pant 50 values of 40 and 46 °C, respectively, whereas 58 % of species in our data set had pant 50 values below 40 °C. We therefore predict that most of the latter species are already vulnerable to increasing T airs.
This study presents a novel method for large-scale and low-cost assessment of variation in behavioural patterns of heat stress in bird communities. Our study shows that systematic inter-specific variation in panting and gular flutter is related to the drinking ecology of species, and to some extent, their body mass and activity patterns. We propose that this approach could greatly supplement integrative studies on the trade-offs between energy and water demands, foraging effort and thermoregulation under hot conditions. We further propose that this method could be developed as a proxy for investigating community-level response to high temperatures, and that it would be particularly relevant to predict vulnerability to climate warming scenarios. However, to fully understand the thermal physiological trade-offs associated with heat dissipation thresholds we still need to determine if variation in pant 50 is associated with species-level physiological differences, other than those driven by intrinsic factors such as body mass and activity demands. A small number of studies have already demonstrated that HDBs represent behavioural trade-offs with potential fitness consequences [13]. However, to further understand links between HDB and thermal physiological trade-offs that may underpin vulnerability, further investigation should address the following questions: 1) what are the relationships between heat dissipation patterns and T b regulation? We predict that lower pant 50 and wing 50values could be related to lower tolerance of T b elevations; 2) is heat dissipation effort indicative of dehydration risk? We predict species with low pant 50 values to show greater daily water demands and a greater risk of dehydration on hot days; 3) How flexible are temperature-related HDB, activity and T b patterns as a result of food and water supply? We predict that there will be variation in species' capacity to adjust their thermoregulatory patterns and this may be linked to adaptation to arid environments. In conclusion, our study shows that interspecific variation in HDBs, together with information on body size, physiology and ecology has the potential to provide community-level assessments of the thermoregulatory trade-offs that species confront at high T airs. We hope that, together with further research on the relationships between HDBs, T b regulation and dehydration risk, these findings will form a foundation for using low-cost field-based observational studies to assess vulnerability to climate change.
BEMs:
Bioclimatic envelope models
EWL:
Evaporative water loss
GLS:
Generalized linear models
Heat dissipation behaviour
M b :
Body mass
pant 50 :
Air temperature where panting behaviour occur in 50 % of cases
PGLS:
Phylogenetic generalized linear models
prop_act :
Proportion of observations where birds were mobile at air temperatures between 35 and 40 °C
prop_pant :
Proportion of observations where birds were panting at air temperatures between 35 and 40 °C
prop_sun :
Proportion of observations where birds were exposed to full sun at air temperatures between 35 and 40 °C
prop_wing :
Proportion of observations where birds were wing-drooping at air temperatures between 35 and 40 °C
rest 50 :
Air temperature where resting behaviour occur in 50 % of cases
shade 50 :
Air temperature where shade-seeking behaviour occur in 50 % of cases
T air :
T b :
wing 50 :
Air temperature where wing-drooping behaviour occur in 50 % of cases
Thomas CD, Cameron A, Green RE, Bakkenes M, Beaumont LJ, Collingham YC, Erasmus BFN, Ferreira de Siqueira M, Grainger A, Hannah L, et al. Extinction risk from climate change. Nature. 2004;427:145–8.
Araújo MB, Thuiller W, Pearson RG. Climate warming and the decline of amphibians and reptiles in Europe. J Biogeogr. 2006;33:1712–28.
Huntley B, Collingham YC, Green RE, Hilton GM. Potential impacts of climate change upon geographical distributions of birds. Ibis. 2006;148:8–28.
Lawler JJ, Shafer SL, White D, Kareiva P, Maurer EP. Projected climate-induced faunal change in the Western Hemisphere. Ecology. 2009;90(3):588–97.
Thomas CD, Franco AMA, Hill JK. Range retractions and extinction in the face of climate warming. Trends in Ecology and Evolution. 2006;21(8):415–6.
Peterson AT. Predicting species' geographical distributions based on ecological niche modeling. Condor. 2001;103:599–605.
Briscoe NJ, Handasyde KA, Griffiths SR, Porter WP, Krockenberger AK, Kearney MR. Tree-hugging koalas demonstrate a novel thermoregulatory mechanism for arboreal mammals. Biol Lett. 2014;10:20140235.
Briscoe NJ, Kearney MR, Taylor CA, Wintle BA. Unpacking the mechanisms captured by a correlative species distribution model to improve predictions of climate refugia. Glob Chang Biol. 2016;22(7):2425–39.
Kearney M, Porter WP, Williams C, Ritchie S, Hoffmann AA. Integrating biophysical models and evolutionary theory to predict climatic impacts on species' ranges: the dengue mosquito Aedes aegypti in Australia. Funct Ecol. 2009;23(3):528–38.
Kearney MR, Wintle BA, Porter WP. Correlative and mechanistic models of species distribution provide congruent forecasts under climate change. Conserv Lett. 2010;3(3):203–13.
Humphries MM, Thomas DW, Speakman JR. Climate-mediated energetic constraints on the distribution of hibernating mammals. Nature. 2002;418:313–6.
Krockenberger AK, Edwards W, Kanowski J. The limit to the distribution of a rainforest marsupial folivore is consistent with the thermal intolerance hypothesis. Oecologia. 2012;168:889–99.
du Plessis KL, Martin RO, Hockey PAR, Cunningham SJ, Ridley AR. The costs of keeping cool in a warming world: implications of high temperatures for foraging, thermoregulation and body condition of an arid-zone bird. Glob Chang Biol. 2012;18:3063–70.
Smit B, Harding CT, Hockey PAR, McKechnie AE. Adaptive thermoregulation during summer in two populations of an arid-zone passerine. Ecology. 2013;94(5):1142–54.
Cunningham SJ, Martin RO, Hockey PAR. Can behaviour buffer the implacts of climate change on an arid-zone bird? Ostrich. 2015;86(1–2):119–26.
Cunningham SJ, Martin RO, Hojem CL, Hockey PAR. Temperatures in excess of critical thresholds threaten nestling growth and survival in a rapidly-warming arid savanna: a study of common fiscals. PLoS One. 2013;8(9):e74613.
Smit B, McKechnie AE. Water and energy fluxes during summer in an arid-zone passerine bird. Ibis. 2015;57(4):774–86.
Milne R, Cunningham SJ, Lee ATK, Smit B. The role of thermal physiology in recent declines of birds in a biodiversity hotspot. Conservation Physiology. 2015;3(1):cov048
Whitfield MC, Smit B, McKechnie AE, Wolf BO. Avian thermoregulation in the heat: scaling of heat tolerance and evaporative cooling capacity in three southern African arid-zone passerines. J Exp Biol. 2015;218:1705–14.
Bakken GS. Measurement and application of operative temperatures in ecology. Am Zool. 1992;32(2):194–216.
Wolf BO, Walsberg GE. Thermal effects of radiation and wind on a small bird and implications for microsite selection. Ecology. 1996;77(7):2228–36.
Dawson WR. Temperature regulation and water requirements of the brown and Abert towhees, Pipilo fuscus and Pipilo aberti. In: Bartholomew GA, Crescitelli F, Bullock TH, Furgason WH, Schechtman AM, editors. University of California Publications in Zoology, vol. 59. Berkeley: University of California Press; 1954. p. 81–123.
Dawson WR, Whittow GC. Regulation of body temperature. In: Whittow GC, editor. Sturkie's avian physiology. New York: Academic Press; 2000. p. 343–90.
Bartholomew GA, Dawson WR. Body temperatures in California and Gambel's quail. Auk. 1958;75:150–6.
Bartholomew GA. Body temperature and energy metabolism. In: Gordon MS, editor. Animal physiology: principles and adaptation. New York: Macmillan; 1972. p. 298–368.
Finlayson HH. Heat in the interior of South Australia – holocaust of bird-life. South Australian Ornithologist. 1932;11:158–60.
Saunders DA, Mawson P, Dawson R. The impact of two extreme weather events and other causes of death on Carnaby's Black Cockatoo: a promise of things to come for a threatened species? Pac Conserv Biol. 2011;17:141–8.
Bartholomew GA, Dawson WR. Thermoregulatory behavior during incubation in Heermann's Gulls. Physiol Zool. 1979;52(4):422–37.
Bartholomew GA, Hudson JW, Howell TR. Body temperature, oxygen consumption, evaporative water loss, and heart rate in the poor-will. Condor. 1962;64(2):117–25.
Lasiewski RC, Bartholomew GA. Evaporative cooling in the poor-will and the tawny frogmouth. Condor. 1966;68:253–62.
Edwards EK, Mitchell NJ, Ridley AR. The impact of high temperatures on foraging behaviour and body condition in the Western Australian Magpie (Cracticus tibicen dorsalis). Ostrich. 2015;86(1–2):137–44.
Catry I, Catry T, Patto P, Franco AMA, Moreira F. Differential heat tolerance in nestlings suggests sympatric species may face different climate change risks. Clim Res. 2015;66(1):13–24.
Tieleman BI, Williams JB, Visser GH. Variation in allocation of time, water and energy in hoopoe larks from the Arabian Desert. Funct Ecol. 2003;17:869–76.
Martin RO, Cunningham SJ, Hockey PAR. Elevated temperatures drive fine-scale pattern of habittat use in a savanna bird community. Ostrich. 2015;86(1–2):127–35.
Weathers WW. Physiological thermoregulation in heat-stressed birds: consequences of body size. Physiol Zool. 1981;54(3):345–61.
Dawson WR, Bartholomew GA. Temperature regulation and water economy of desert birds. In: Brown GW, editor. Desert biology. New York: Academic Press; 1968.
Dawson WR, Hudson JW. Birds. In: Whittow GC, editor. Comparitive physiology of thermoregulation. New York: Academic Press; 1970. p. 223–310.
R Core Team. R: a language and environment for statistical computing. Vienna: R Foundation for Statistical Computing; 2012.
Gerson AR, Smith EK, Smit B, McKechnie AE, Wolf BO. The impact of humidity on evaporative cooling in small desert birds exposed to high air temperatures. Physiol Biochem Zool. 2014;87(6):782–95.
Paradis E, Bolker B, Claude J, Cuong H, Desper R, Du-rand B, Dutheil J, Gascuel O, Heibl C, Lawson D, et al. ape: analyses of phylogenetics and evolution. 2013.
Orme D, Freckleton R, Thomas G, Petzoldt T, Fritz S, Isaac N, Pearse W. caper: comparative analyses of phylogenetics and evolution in R. 2013.
Hockey PAR, Dean WRJ, Ryan PG. Roberts birds of southern Africa. 7th ed. Cape Town: John Voelcker Bird Book Fund; 2005.
Jetz W, Thomas GE, Joy JB, Hartmann K, Mooers AO. The global diversity of birds in space and time. Nature. 2012;491:444–8.
Hackett SJ, Kimball RT, Reddy S, Bowie RCK, Braun EL, Braun MJ, Chojnowski JL, Cox WA, Han K-L, Harshman J, et al. A phylogenomic study of birds reveals their evolutionary history. Science. 2008;320:1763–8.
Mesquite: a modular system for evolutionary analysis. Version 2.75. http://mesquiteproject.org
Burnham KP, Anderson DR. Model selection and multi-model inference: a practical information-theoretic approach. 2nd ed. New York: Springer; 2002.
Barton K. MuMIn: Multi-model inference. R package version 0.13.17. In: https://cran.r-project.org/web/packages/MuMIn/index.html. 2010
Warton DI, Hui FKC. The arcsine is asinine: the analysis of proportions in ecology. Ecology. 2011;92(1):3–10.
Blomberg SP, Garland T, Ives AR. Testing for phylogenetic signal in comparative data: behavioral traits are more labile. Evolution. 2003;57(4):717–45.
Battley PF, Rogers DI, Piersma T, Koolhaas A. Behavioural evidence for heat-load problems in Great Knots in tropical Australia fuelling for long-distance flight. Emu. 2003;103(2):97–103.
McKechnie AE, Wolf BO. Climate change increases the likelihood of catastrophic avian mortality events during extreme heat waves. Biol Lett. 2010;6:253–6.
Calder WA, King JR. Thermal and caloric relations of birds. In: Farner DS, King JR, editors. Avian biology, vol. 4. New York: Academic Press; 1974. p. 259–413.
Tieleman BI, Williams JB. The role of hyperthermia in the water economy of desert birds. Physiol Biochem Zool. 1999;72(1):87–100.
Tieleman BI, Williams JB. Effects of food supplementation on behavioural decisions of hoopoe-larks in the Arabian Desert: balancing water, energy and thermoregulation. Anim Behav. 2002;63:519–29.
Maloney SK, Dawson WR. Changes in pattern of heat loss at high ambient temperature caused by water deprivation in a large flightless bird, the emu. Physiol Zool. 1998;71(6):712–9.
Calder W, Schmidt-Nielsen K. Panting and blood carbon dioxide in birds. American Journal of Physiology – Legacy Content. 1968;215(2):477–82.
Marder J, Arad Z. Panting and acid–base regulation in heat stressed birds. Comp Biochem Physiol A Physiol. 1989;94(3):395–400.
Boyles JG, Seebacher F, Smit B, McKechnie AE. Adaptive thermoregulation in endotherms may alter responses to climate change. Integr Comp Biol. 2011;51(5):676–90.
Hoffman TCM, Walsberg GE. Inhibiting ventilatory evaporation produces an adaptive increase in cutaneous evaporation in mourning doves Zenaida macroura. J Exp Biol. 1999;202(21):3021–8.
Marder J, Arieli U. Heat balance of acclimated pigeons Columba livia exposed to temperatures of up to 60 °C Ta. Comp Biochem Physiol. 1988;91A:165–70.
McKechnie AE, Wolf BO. Partitioning of evaporative water loss in white-winged doves: plasticity in response to short-term thermal acclimation. J Exp Biol. 2004;207:203–10.
McKechnie AE, Whitfield MC, Smit B, Gerson AR, Smith EK, Talbot WA, McWhorter TJ, Wolf BO. Avian thermoregulation in the heat: efficient evaporative cooling allows for extreme heat tolerance in four southern Hemisphere columbids. J Exp Biol. 2016;219:2145–55.
Smith EK, O'Neill J, Gerson AR, Wolf BO. Avian thermoregulation in the heat: resting metabolism, evaporative cooling and heat tolerance in Sonoran Desert doves and quail. J Exp Biol. 2015;218(22):3636–46.
Wolf BO, Walsberg GE. Respiratory and cutaneous evaporative water loss at high environmental temperatures in a small bird. J Exp Biol. 1996;199:451–7.
Tieleman BI, Williams JB. Cutaneous and respiratory water loss in larks from arid and mesic environments. Physiol Biochem Zool. 2002;75(6):590–9.
Ro J, Williams JB. Respiratory and cutaneous water loss of temperate-zone passerine birds. Comparative Biochemistry and Physiology A. 2010;156:237–46.
van Wilgen NJ, Goodall V, Holness S, Chown SL, McGeoch MA. Rising temperatures and changing rainfall patterns in South Africa's national parks. Int J Climatol. 2016;36(2):706–21.
Kruger AC, Sekele SS. Trends in extreme temperature indices in South Africa: 1962–2009. Int J Climatol. 2013;33:661–76.
We thank E Oppenheimer and Son, and the Tswalu Foundation for sponsoring a field vehicle and accommodation at TKR. We thank Robert Sutcliffe, David Nkosi, Dawn Cory Toussaint, Carol Hoole, Hardie van Tonder, Elsabie Templeton and Jorge Berdón for their assistance in the field. We thank Tom Flower for collecting additional data on some species. Maxine Whitfield is thanked for her valuable comments on the discussion of the manuscript.
This research was supported by funding from National Research Foundation and the DST-NRF Centre of Excellence at the Percy FitzPatrick Institute to AEM and PARH.
Availability of data and material
All raw data are available in Aditional file 2.
BS, ROM, SJC, AEM and PARH developed the conceptual framework. BS, ROM and GZ collected data. BS analysed conducted data analyses. BS and AEM wrote the manuscript. ROM and SJC edited the manuscript. All authors read and approved the final manuscript.
We have obtained consent to publish the data collected by Tom Flower at KRR. We declare there are no further contents of this manuscript that require consent to be published.
Department of Zoology, Nelson Mandela Metropolitan University, PO Box 77000, Port Elizabeth, 6031, South Africa
B. Smit
Percy FitzPatrick Institute of African Ornithology, DST-NRF Centre of Excellence, University of Cape Town, Rondebosch, 7701, South Africa
G. Zietsman, R. O. Martin, S. J. Cunningham & P. A. R. Hockey
DST-NRF Centre of Excellence at the Percy FitzPatrick Institute, Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield, 0028, South Africa
A. E. McKechnie
G. Zietsman
R. O. Martin
S. J. Cunningham
P. A. R. Hockey
Correspondence to B. Smit.
P. A. R. Hockey, deceased.
Summary of heat dissipation observations and statistics. (DOCX 82 kb)
Behavioural observation data of birds collected during the austral summers (November-March) of 2009/2010 and 2010/2011. (XLSX 1.09 mb)
Raw data as presented in Table S1 and Table S2. (XLSX 63 kb)
Smit, B., Zietsman, G., Martin, R.O. et al. Behavioural responses to heat in desert birds: implications for predicting vulnerability to climate warming. Clim Chang Responses 3, 9 (2016). https://doi.org/10.1186/s40665-016-0023-2
Accepted: 28 September 2016
Vapour Pressure Deficit
Evaporative Cool
Large Bird
Mechanistic approaches to predicting climate change impacts on endotherms


text:
Grade Level:
PreK, K, 1, 2
by Mary Hoffman A guide for parents, teachers, and group leaders to accompany the reading of this picture book. The guide below provides before, during, and after-reading discussion questions. Choose from activities and discussion questions to build children's understanding of generosity, community, and service to others. Spanish Version Attached.
AmazingGrace.jpg
We hope you feel inspired by the story of Amazing Grace. It is not difficult to understand why Grace is so creative and confident when you meet her supportive family. When we have the support of our families, it can feel like we can do anything. Talk about the many ways that Grace's family supports her. Connect that to the many ways your family members support and encourage each other. Extend the idea to exploring further ways you can support each other in the family and community—especially siblings. The title of this book is wonderful because of the many meanings of the word grace. Look up the meanings in the dictionary. Talking about the meanings of words is a fun family activity. If you don't have a family dictionary, it is a great investment.
Before Reading
ASK: Draw a picture of your family. (Each person, including the reader, draws his or her own picture.) Label the picture with names. Talk about who is in your family and compare pictures—what is the same and different? What is the best thing about families? What do families do for each other? How do families support each other?
SHOW: Look at the cover and pictures on the title page. Talk about what you can tell about Grace from these pictures.
CONNECT: Can you think of a time that you wanted to try something new and someone told you "that's too hard for you"? How did that make you feel and how did you respond? We're going to read a story about a girl who didn't let those words stop her from trying.
During Reading
ASK: How did Grace act when told she couldn't be Peter Pan?
SHOW: Compare the attitudes and actions of the different characters (classmates, mother, grandmother, Grace). Which things were helpful and which were harmful?
CONNECT: How can you support and encourage your family members? How do they support and encourage you?
After Reading
ASK: What do you think of the line "You can be anything you want if you put your mind to it?" Have you ever put your mind to something? How did it feel??
SHOW: Look at pictures throughout the book. Find examples of Grace's family loving and supporting her.
CONNECT: How did Grace work toward becoming Peter Pan? Why doesn't it matter if she is black or a girl? Think about what you would like to be or do. How can you work toward it?
Make a simple puppet stage and act out a familiar story such as a fairy tale. Work together as a family to gather the supplies and practice the story.
Stage Ideas:
Prop up couch cushions and use blankets to hide behind.
Put two chairs together and drape a blanket over the seats. Hide behind the blanket and use the seats as the stage.
Cut a large rectangle-shaped hole in a large box. Put the puppets through the hole.
Puppet ideas:
Stick puppets
Small stuffed animals
Make up/Act out stories about people or animals who have been told they couldn't do something, but they work hard and believe in themselves and do it! Talk as a family about who the characters are, the problem, and the solution.
Use dress-up clothes to make a costume of a favorite character—use some of Grace's characters for ideas.
Have a family meeting to discuss supporting and encouraging each other. Talk about ways to say "good job" and "I know you can do it." Have each person make a plan to try something new and difficult this month. Listen to each others' ideas and make a plan for supporting and encouraging each other.
Sing "Amazing Grace" together as a family.
Look up the meaning of "grace" in the dictionary. Which definitions seem to fit Grace from the story.
Think of one amazing thing about each member of your family. Draw a picture for each person and copy and finish this sentence on each page: The amazing thing about _________ is ________________________________________. Give the finished pictures and sentences to your family members. (As an alternative, put your own family event/tradition in place of a name. Examples: The amazing thing about our family is… The amazing thing about our holiday celebration is… The amazing thing about our vacation was…)
A Chair For My Mother
Julius: The Baby of the World
Alexander Who Used to Be Rich Last Sunday
Links & Attachments
Spanish Version of Literature Guide

redpajama_set_name: RedPajamaCommonCrawl


text:
Recap, Series, Victorian Period
Hunderby: Baby Blues
Previously on Hunderby: Helene got a dog, Matilda died (with an assist from both Dorothy and Edmond), and Dorothy got her hands on Helene's incriminating locket.
The funeral's over and the family is sitting down for the reading of the will. Basically, Edmond will get everything if he and Helene have a child within the year. If there is no child, everything is to be sold and the money used to build an underwater memorial to those lost when the Bethany Rose sank. Dorothy isn't mentioned at all. Ha!
At church that Sunday, Edmond reminds everyone that Dorothy will be holding her regular healing circle that day at noon. He then prays that he and Helene be blessed with a child, adding that all children are born filthy savages. Well, all right, then.
At home for lunch, Helene's being made to eat bull's testicles, I think. Needless to say, her appetite isn't great. Edmond pointedly tells her he'll be upstairs and leaves, giving Dorothy time to snipe at Helene for not eating enough. Edmond thankfully saves her by calling for her, so up she goes for more of the worst non-sex ever. Once again, Edmond hasn't made it inside, apparently. Edmond looks out the window and spots shirtless Jeff, which gets him all excited. He finishes up and Dorothy comes right in to offer him some bubbly milk.
Later, Dorothy's got her healing circle going. This must be a pretty healthy parish, because they're focusing on trying to cure a man of baldness. Unsuccessfully, of course.
Edmond, meanwhile, has gone to pay a visit to Brother Joseph, who gives Edmond a massage and notes that he seems rather tense. Edmond confides that he's noticed Helene has a clitoris, which he thinks is some sort of deformity. Oh, Victorians. Again, I'd think this was absurd if it wasn't actually how people thought until shockingly recently. Joseph says his wife has mentioned such things, which are said to drive women mad. Edmond also admits that looking at Helene is something of a turnoff for him, so Joseph suggests he cover her face, as he does with his wife, and conjure up a "more stimulating scene." For Joseph, that apparently means an altar boy, who comes in briefly and hastens out, probably sensing the creepy atmosphere.
Dorothy's circle has turned its attention to Helene, who's lying on her back while the others sing a strange song calling for a strong infant to, basically, explode from her thighs.
Afterwards, Helene's weeping in the churchyard, where she's found by Hester, a woman in a wheelchair. Hester's sweet and comforts Helene, saying she felt like crying the first time she was in the healing circle too. Turns out the circle's useless, to her, at least, but she's sure Helene will be all right. Helene admits that she would really love to have a child, and then feels bad because obviously Hester can't have one. Hester tells her not to worry about it, because she has a wonderful husband instead. And guess who that is? Dr. Fogarty! And he's walking their way with a bouquet of flowers and a look on his face that says, "oh, crap, my crush is talking to my wife." Yeah, that's awkward for everyone involved.
Edmond comes over and tactlessly refers to Helene as "stout legs" before bundling her off for another fruitless coupling. As she goes, Helene drops her handkerchief, which Hester recognizes as belonging to her husband. Helene takes it from her and hurries away, while Dr. F presents his wife with her wildflower bouquet.
At Hunderby, Dorothy shows Helene and Edmond the nursery she's created for the baby. It's an almost empty, cell-like stone room with tiny slit windows and a cradle the Addams family would love. It's all black, spiky, iron bars. Lovely. Dorothy tells the prospective parents that babies should sleep 14 hours straight, and if they do cry, it's because the devil has gotten into them and they should be left to fight it out. Even Edmond seems a bit put off by this.
Later, Dorothy presents Helene with more balls and the locket. Helene lies pretty admirably and says the "Elizabeth" mentioned on the locket is her middle name, and the man inside is her late brother. She tries to take the locket, but Dorothy won't give it up.
Helene heads to Edmond's room, where she finds him dressed in a long nightdress and white wig. He explains that Joseph suggested some Biblical roleplaying to get them both in the mood, so Helene will be playing Job, while Edmond will be Jehovah, coming to rain down punishments. Kinky!
And useless, it seems. Though Edmond once again glimpses Jeff through the window and gets excited, when Helene looks up at him (still wearing her Job beard), he finds himself unable to finish.
Edmond presents Jeff with a footman's livery and tries very hard not to check out Jeff's bare bum while he changes. Later, Edmond's enjoying the sight of some pictures of naked savages in some missionary tract when Dorothy comes in and shoves Helene's bloody sheets in his face, informing him that "Satan's jam has once again burst [Helene's] bristled bun." Wow. Where does Julia Davis come up with this stuff? In his annoyance, he throws a spoon across the room, accidentally hitting Helene in the face as she walks in.
Doc Fogarty is called for, and of course he immediately notices the bruise on her cheek. He's concerned, but Edmond angrily tells him that Helene's just clumsy and Fogarty's there to inspect her womb, not her cheek.
Helene and the doctor repair to her bedroom for the exam, which shows she's perfectly normal. Perfectly normal for a woman who's already had a child, that is.
Helene, of course, freaks out, and begs Fogarty not to tell Edmond. He reassures her he won't breathe a word but tells her she can certainly have more kids. Helene tells him the baby was the product of rape at the hands of the humpbacked man whose picture is in her locket, and that the baby died. Fogarty comforts her and makes a confession of his own: he was the one who crippled Hester. It was an accident, of course: he got drunk the night before their wedding, because he realized he didn't love Hester, and then got on his horse to go home and accidentally ran her down. Somehow, she doesn't know that it was Fogarty who did it, even though she was running outside to meet him at the time, so maybe she hit her head or something. Or she's lying about not knowing it was him.
Fogarty next asks to examine Edmond, who agrees, but turns down Dorothy's creepy offer of assistance. While he's otherwise occupied, Helene runs to the kitchens in a panic, calling for Annie. When Annie appears, Helene tells her Fogarty knows about the baby she had. Annie tells her not to stress, because this "wouldn't be the first queer child that's haunted these walls." Iiiiinteresting. Anyway, she's sure Fogarty won't tell, and anyway, it's not as if Helene killed anyone. Well, except the father of her child, as Helene flashes back to her bashing the man's head in. Annie suggests they go play with Susan, and once they're gone, Dorothy emerges from a hiding place on the other side of the table.
Fogarty examines Edmond and…well, let's just say that everything seems to be working as it should.
Dorothy, armed with some nasty looking shackles, lets herself into the room that's always locked up, where the creepy wailing comes from.
EditorBee September 12, 2012 black comedy, comedy, Julia Davis
One thought on "Hunderby: Baby Blues"
Pingback: Hunderby: I Want You, I Need You, Oh Baby, Oh Baby « The Armchair Anglophile
Previous Previous post: The Battle of Stirling Bridge
Next Next post: What Date?


text:
Page-load survey informs net neutrality debate
By Grant Gross
IDG News Service | PT
About a third of Internet users will abandon slow-loading Websites within five seconds, and users of mobile devices expect Website performance to be as good as it is on wired computers, according to a new survey that may have implications for the network neutrality debate in the U.S.
Thirty-two percent of Internet users would leave a Web page if it doesn't load within five seconds, according to the survey, released Tuesday by Gomez, the web performance division of Compuware, an IT application performance product vendor. However, only 17 percent of mobile-device users would stick around if a Web page fails to load within five seconds, according to the Web-based survey of 1,004 Internet users completed in late June.
The survey's results suggest that Websites can be significantly disadvantaged by poor performance and bad connections, said Gomez CTO Imad Mouline. Thirty-seven percent of respondents said a slow-loading Website would discourage them from coming back, and 27 percent said a slow-loading site would make them more likely to visit a competing site.
Gomez takes no position on a long-standing argument in Washington, D.C., over the need for net neutrality rules, but the survey results may inform the debate, Mouline said. The survey shows Web users' expectations for Website performance are rising, he said.
Some Web companies may see that the survey results show a need for net neutrality rules from the Federal Communications Commission or Congress, Mouline said. Other companies may see the opposite—that without net neutrality rules they could potentially pay broadband providers for priority access to their customers, he said.
"You can see it both ways," Mouline said. "One, 'let's make sure net neutrality is in place, so that carriers don't have the ability to decide who gets better performance and who doesn't.' There might be others who say, 'no, I'm a corporation, and I'm willing to pay a little bit extra to make sure that I get a leg up on the competition.'"
Gomez hopes the survey data will allow people on both sides of the debate to see "what's really at stake out there," he added.
In early August, Verizon Communications and Google unveiled a net neutrality proposal that would exempt mobile broadband services from rules enforced by the FCC. The survey, however, suggests mobile customers expect Web pages to load as fast or faster than on the wired Internet, Mouline noted.
Thirty-two percent said they expect Websites to load faster or just as fast on their mobile phones as on their wired computers. Another 18 percent said they expected Websites to load nearly as fast on their mobile phones, and 33 percent said they expect Websites on mobile phones to load slightly slower.
A spokeswoman for CTIA, a trade group representing mobile carriers, wasn't immediately available for comment.
Two-thirds of the people responding to the survey said they encounter a slow-loading Website at least once a week, and 46 percent said they abandoned slow-loading sites very frequently or somewhat frequently.


text:
Doniya Malik Biography
Born in: Bradford, England
Famous as: Instagram star, Fashion blogger, sister of Zayn Malik
British Women Aries Women
father: Yaser Malik
mother: Patricia Brannan Trisha Malik
siblings: Safaa Malik, Waliyha Malik, Zayn Malik
City: Bradford, England
Safaa Malik
Waliyha Malik
Katherine Schwa...
Doniya Elisha Malik is a British beauty and fashion blogger, Instagram star, and entrepreneur. She is the older sister of Zayn Malik, a former member of the boy band One Direction. Doniya was raised in Bradford, England, and like the rest of her siblings, attended Tong High School. After receiving her college degree from the University of Bradford, she decided to pursue a career in beauty and fashion, as she has been interested in these fields since she was a child. She has set up her own beauty website and runs a beauty salon in Bradford with her mother and sister. While she garnered fame initially because of her singer brother, she has since managed to establish herself as a prominent social media influencer. She has over 463,000 followers on Twitter and more than 666,000 followers on Instagram.
https://www.instagram.com/p/BnW0RHQB0sF/?taken-by=doniyabeauty
https://www.instagram.com/p/BnOlWxChqxV/?taken-by=doniyabeauty
https://www.instagram.com/p/BnJ78U1hOl8/?taken-by=doniyabeauty
https://www.instagram.com/p/BfeIXUKH8RQ/?taken-by=doniyabeauty
https://www.instagram.com/p/BeiyOoyB7u3/?taken-by=doniyabeauty
https://www.instagram.com/p/BccycmLBYaI/?taken-by=doniyabeauty
https://www.instagram.com/p/BPfsvrZBbZL/?taken-by=doniyabeauty
Doniya Malik has always harboured a deep passion for beauty and fashion. After she graduated from college, she decided that working in the field of fashion would be the ideal profession for her. As a result, she began to work towards becoming a beauty and fashion blogger. At some point, she set up a website under the name Doniyabeauty, which is currently used to market Armani products.
In early 2016, Doniya, along with her mother Trisha and sister Waliyha, set up a beauty salon called Waliyha Beauty in Bradford. According to their website, they provide a broad range of services, including bridal hair and makeup, party hair and makeup, yumi lash lift, semi-perm lash extensions, eyebrow and facial threading, waxing, manicures, facials, pedicures, acrylic nails, and spray tans. Doniya and Waliyha are also building up their very own line of selected makeup products, named Daliyha Beauty. As of 2018, they have released their signature line of eyelashes.
According to a report published in the Daily Star in December 2016, she was working as a customer service advisor of a leading gas and electric supplier at the time. Her job mainly entailed dealing with general enquires.
The Most Popular US Veterans
The Sexiest Men Of 2020, Ranked
The Best Black Actresses Of All Time
Doniya was born on April 19, 1992, in Bradford, England to Yaser and Patricia Brannan "Trisha" Malik. Zayn, born on January 12, 1993, is about a year younger than her. She also has two younger sisters: Waliyha (July 23, 1998) and Safaa (September 13, 2002). Yaser is a British Pakistani while Trisha is of English and Irish descent. When she married Yaser, Trisha converted to Islam, which is his religion.
Doniya and her siblings grew up in a working-class household, living in a working-class neighbourhood. They all studied at the Tong High School. After graduating high school, she attended the United of Bradford. Doniya and Zayn share a deep bond. Despite Zayn being younger than her, he is very protective of her. She has stated, "Because me and Zayn are very close in age, we've grown up together... Actually he bosses me around, he acts like a big protective brother which is quite nice at times." She has also talked about how Zayn's meteoric rise to fame has affected the family. She has admitted that it has changed their lives quite a lot, adding that it has also brought about many opportunities. It all began when she was only 18 years old and everything had felt surreal and weird. However, she has become accustomed to it with time.
Follow Doniya Malik On:
Who Is The Greatest Female Warrior In History?
The Top 25 Wrestling Announcers Of All Time
Celebrities Who Are Not In The Limelight Anymore
Doniya Malik Bio As PDF
- Doniya Malik Biography
- https://www.thefamouspeople.com/profiles/doniya-malik-42228.php
(British)
Laura Alvarez
(British, Mexican)
Haya bint Hussein
(Emirati, Jordanian)
(South African, Zimbabwean)


text:
Reconciliation Through the Arts (IRA1-V10)
Video clips of artists, Indigenous leaders and public servants discussing the role of the arts in the reconciliation process.
Reconciliation Through the Arts
Transcript: Reconciliation Through the Arts
Within our Nation, the Mohawk Nation, there was no language word for art. We called it beauty. It was a way of life. It was how we lived day to day, and the path, the path of beauty.
Cowboy Smithx.
Good to see you.
Good to see you again.
I'm glad you made it.
Yeah, well, I'm really happy just to be here on your land, you know.
I've heard that before.
---Laughter
Elder in the Making is kind of a road trip story, actually, between a Chinese Canadian (me) and Cowboy Smithx, as we go learning about our shared history and our home. What started off as kind of this small exploration grew into a huge exploration of Indigenous culture and history in Southern Alberta, on the traditional territories of the Blackfoot.
Actually, you know, shoot the beautiful landscapes that exist out there and understand what they mean to the people of the land. I can't even say it was so close to home; it is home.
What is it that you would want to tell us, the public servants, on how we should be building better relationships with Indigenous Peoples?
Making a genuine connection with individuals, specifically elders. You know, they carry the most knowledge in our communities. It's really a conversation about effort. I mean, you've got to go beyond what's in your policy here, at the School. I mean, you've got to make it a personal journey and not one that is part of the institution you represent. You can't expect anything. You can't think there's a certain level you are going to get to if you spend four years with an elder. It doesn't work that way.
Here's a dangerous conversation about pan-Indianism. We are not all the same. We all have different circumstances and connections because the land itself, the physical geography, the geology, expresses itself in different ways.
Definitely, you have to go above and beyond what siloed expectations you may have which may be connotated to your work or connotated to some sort of obligation. Even tokenism is always kind of a dangerous thing to get involved with. But definitely make it genuine, make it authentic, if you're going to connect to somebody. Know your history.
It's important to know what you're actually saying before you say it. Be considerate, right? So, when I hear things like, "Well, we'll let the First Nations do their dance at the beginning, or we'll let them…" I mean, come on, we're done being "let in." I mean, we're foreigners in our own territory enough that we don't need to be let anywhere within our own territories.
So, when it comes to the language of any type of circumstance, it's important to be very aware of what you're saying. Inclusion is a form of othering and it's… You know, I'm saying to be respectful.
We're seeing all these types of stories like Elder in the Making , like the Truth and Reconciliation Report, which I recommend everybody read. These all help to start shaping people's understanding of how we came to where we are.
---Music
It's essentially a love story. It's about Annie, who is a young, Indigenous girl who is not in touch with her culture. She meets Gordon, who is a survivor, and he teaches her about the Indian Residential School story.
I felt it was timely, and I felt that art can bring about change. I want to make people aware.
Truth brings reconciliation; reconciliation, I think, can bring harmony; and harmony can bring prosperity.
Reconciliation is a word I've only started using recently. The fact that we're even having this conversation is quite inspiring. Hopeful is definitely a part of that, but we've been hopeful for too long. It's time to really take agency over these conversations and bring them into fruition.
We're not going to come and say, "Oh, it's time to come to Mohawk lands." You know, we're not going to do that, it's not our place. It's your place to come and ask, and it's in the asking you will grow, learn. But more importantly, love for yourself and others.
---Chants


The primary objective of SIRENE is to simulate the response to neutrino events of any type of high energy neutrino telescope. Additionally, it implements different geometries for a neutrino detector and different configurations and characteristics of photo-multiplier tubes (PMTs) inside the optical modules of the detector through a library of C+ + classes. This could be considered a massive statistical analysis of photo-electrons. Aim of this work is the development of a multithreaded version of the SIRENE detector simulation software for high energy neutrinos. This approach allows utilization of multiple CPU cores leading to a potentially significant decrease in the required execution time compared to the sequential code. We are making use of the OpenMP framework for the production of multithreaded code running on the CPU. Finally, we analyze the feasibility of a GPU-accelerated implementation.


text:
Notices to Race - Waitakere Champs
Notices to Race - 2019-2020
Sailing Instructions - 2019-2020
News from Taikata Yacht Club
Latest news from and about the club, its events, and its members.
Site Admin's Blog
Auckland Champs - 2018
April 1, 2018By Site Admin Results auckland 0
In the weekend 24-25 March Taikata held its Auckland Frostbite Champs. The club welcomed a new sailor (who had obviously done it before) sailing a borrowed Boat (Asahi).
Day 1 was a brisk wind giving some exciting moments for all. The scratch results were shared evenly among 3 boats. Days 2 saw a complete change with very light winds. The competition was then done to two with our visitor in Asahi taking the honours.
With the new handicaps set for the second half of the season it was Limeburner that prevailed in the handicap stakes. We must acknowledge that Ashia was pushing here also taking out second place.
Well done to all the sailors and thanks to the support personnel!
Scratch Results
Sail No Boat Race 1 Race 2 Race 3 Race 4 Race 5 Race 6 Total Corrected Final Score
76 Asahi 1 3 2 3 2 1 12 9 1
53 Matitai 3 1 1 4 3 10 22 12 2
187 Orca 5 5 6 1 4 5 26 20 3
29 Sarnia 7 6 4 2 6 2 27 20 3
190 Sub Zero 2 2 3 8 8 12 35 23 5
85 Footprint 8 7 5 11 1 3 35 24 6
206 Shadze 12 12 7 5 5 4 45 33 7
110 Limeburner 4 9 8 6 9 7 43 34 8
116 Rapscallion 6 10 9 7 7 6 45 35 9
127 Scrorcha 9 8 10 9 11 8 55 44 10
149 Family Affair 10 4 11 12 12 12 61 49 11
Handicap Results
76 Asahi 3 6 8 7 2 0 26 18 2
127 Scrorcha 5 4 2 2 11 7 31 20 3
53 Matitai 4 3 3 8 7 9 34 25 5
187 Orca 6 7 10 5 6 5 39 29 8
206 Shadze 12 12 9 6 5 4 48 36 10
Waitakere Champs 2018-19
The Waitakere Championships were held for the 2018-19 season over the weekend of December 15 and 16. In terms of participation it was a great competition with 14 Frostbites sailing each day. In weather terms it was a true test. Day 1 was a light but consistent breeze with each of the three races completed in almost identical time for first and last boat (+/- 2 minutes). Line honours were shared between Sea Lion (2) and Sub Zero (1). On Day 2 the wind dropped to 'very light'. This brought Footprint (2) and Sarnia (1) to the fore to take the gun. Overall Sea Lion did enough to take the Championship.
The handicap competition was dominated by Limeburner who took the honours with 5 wins with the other race taken by Asahi.
With six races completed it can only be considered a successful event for the club and the Frostbite class.
Scratch:
125 Sea Lion 1 2 1 3 2 5 14 9 1
85 Footprint 4 5 8 1 3 1 22 14 2
206 Shadze 3 4 3 2 5 6 23 17 3
190 Sub Zero 2 1 6 6 11 15 41 26 6
149 Family Affair 7 7 2 8 6 15 45 30 7
116 Rapscallion 10 9 9 7 7 2 44 34 8
57 Kotiri 9 11 10 9 8 8 55 44 9
128 Pollyanna 11 10 11 10 10 7 59 48 10
127 Scorcha 12 13 12 11 13 9 70 57 11
23 Amber 13 12 13 12 12 11 73 60 12
97 Corrugated Cannery 14 14 14 13 14 10 79 65 13
308 Asahi 8 8 5 25 25 25 96 71 14
90 Incognito 25 25 25 DSC 9 15 99 74 15
Handicap:
110 Limeburner 1 1 3 1 1 1 8 5 1
57 Kotiri 4 5 5 5 2 7 28 21 2
85 Footprint 9 6 12 3 4 3 37 25 3
206 Shadze 6 3 6 4 10 8 37 27 4
29 Sarnia 10 7 7 6 3 6 39 29 5
116 Rapscallion 12 11 9 2 8 2 44 32 6
149 Family Affair 3 12 2 7 9 15 48 33 7
125 Sea Lion 7 4 8 8 6 9 42 33 7
127 Scorcha 8 8 4 10 12 5 47 35 9
190 Sub Zero 5 2 10 9 11 15 52 37 10
128 Pollyanna 11 10 11 11 7 4 54 43 11
23 Amber 13 13 13 12 9 11 71 58 12
Welcome to 2018-2019 Season
September 2018 and is warming up for a new season. Time to dust of the Frostbite, get a new WOF (yeah right!) and try and remember all those little things you were going to fix in the off-season. Too late now!
The schedule is posted: http://www.taikata.co.nz/Schedule
There is a new orange button above the calendar called iCal. Click that and you can import the schedule into your personal calendar of choice; iCalendar, google calendar, outlook … No excuse for forgetting a race day (or being late).
Event number 1:
Social Sailing/Shakedown
Start Date:Sunday, 16 September 2018
Time: 11:00 a.m.
High Tide: 12.18pm 3.1m
Location: Taikata Sailing Club
Description: Social Sailing - Shakedown shakedown Tide: 12.18pm 3.1m
Summer Series Race 1 – 2018-19
The competition proper started this weekend for the 2018-19 season. The turnout was good with 13 boats. In light airs it was Footprint once again showing its speed and holding off the challenge to take line honours. Pollyanna (sailing as the club boat while under going as face lift), took the handicap gun.
Sail No Boat Finish Duration Scratch Handicap
85 Footprint 11:36:27	 01:36:27	 1 4
29 Sarnia 11:36:49	 01:36:49	 2 6
190 Sub Zero 11:37:25	 01:37:25	 3 7
142 Team Effort 11:37:34	 01:37:34	 4 10
116 Rapscallion 11:39:21	 01:39:21	 5 2
128 Pollyanna 11:40:10	 01:40:10	 6 1
134 White Heather 11:44:25	 01:44:25	 7 3
149 Family Affair 11:44:45	 01:44:45	 8 9
57 Kotiri 11:48:21	 01:48:21	 9 5
16 Kraka Jak 11:50:22	 01:50:22	 10 8
23 Amber 11:52:55	 01:52:55	 11 12
809 Vitamin C 11:57:29	 01:57:29	 12 11
127 Scrorcha 12:08:47	 02:08:47	 13 13
Back into the Summer series for 2019 with 2 races to go. WindPredict was promising 10 knots from the East. Unfortunately it under-delivered with a very light breeze to start, but filling in with a bit more consistent pressure as the race went on. Very tight racing was had with all bouts finishing within 10 minutes after 1.5 hours of sailing. Sarnia sailed strongly to take the gun with Limeburner picking up another handicap win.
187 Orca 12:27:12	 01:27:12	 2 11
85 Footprint 12:28:28	 01:28:28	 4 10
110 Limeburner 12:28:55	 01:28:55	 6 1
23 Amber 12:34:34	 01:34:34	 9 6
128 Pollyanna 12:35:00	 01:35:00	 10 8
57 Kotiri 12:35:56	 01:35:56	 11 4
Another great turnout with 14 boats racing. A new challenge today with fickle winds that couldn't decide what direction they wanted come from. Once again it was Team Effort that showed the fleet the way to take the win. Handicap honours went to Footprint.
142 Team Effort 10:23:57	 01:13:57	 1 5
53 Matitai 10:25:23	 01:15:23	 3 4
149 Family Affair 10:39:31	 01:29:31	 10 11
97 Corrugated Cannery 10:50:22	 01:40:22	 12 12
90 Incognito 00:00:00	 DNF	 DNF DNF
Summer Series Race 3–2018-19
With 15 boats in the main fleet and a couple of Opti's on the water it was a great day with a breeze to test. It was also a day that brought everything; boat on boat action, a sinking, a walk in the mangroves, flexible attention to the course, a capsize and abandon ship. Even Team Effort which left the fleet in its wake for both scratch and handicap wasn't without some gear challenges.
SailNo Boat Finish Duration Scratch Handicap
310 Charisma 16:09:48	 00:59:48	 3 7
206 Shadze 00:00:00	 DNF	 DNF DNF
57 Kotiri 00:00:00	 DNF	 DNF DNF
6 Mirror 00:00:00	 DNF	 DNF DNF
127 Scrorcha 00:00:00	 DNF	 DNF DNF
Site Admin (41)
1918 2018 2018;waitakere auckland course event postponement results sail Summer Summer;2018
15 Chapman Rd
Waitekere 0610
Usual Sailing Waters: Upper Waitemata Harbour
Commodore: Ashok Magan
Treasurer: John McShane
Taikata Sailing Club Hire: Ashok Magan (021 419704)
© Copyright 2020 by Taikata Sailing CLub | Terms Of Use | Privacy Statement


We put dull, dying and worn off roofs back to life. With generations of experience and knowledge of the latest roofing trends and technology, we deliver extra-ordinary Colorbond roofing results. You can trust us when we say that we are the expert of Colorbond roofing because we deliver results that are quality centric and long-lasting.
You certainly don't want your expensive electronics to get all wet or see your authentic carpet get drenched in the rainwater? Well, this all can happen if you have leaking roofs that allow rainwater to enter the house. Roofs are your security cover from extreme weather conditions and rain is one of them. Often old, dull and worn out roofs develop cracks and holes that make an easy access to rainwater. While this may appear as a small problem, in case of heavy rainfall, thunderstorms and other catastrophe conditions, it can cause heavy water flow in the house or complete damage of the roofs, even worse.


text:
Home About Us News CF Nanobiotechnology has a new atomic force microscope
News Press Releases
CF Nanobiotechnology has a new atomic force microscope
The unique device could be used for testing materials for novel types of body implants
The Core Facility Nanobiotechnology at CEITEC Masaryk University in Brno recently completed the installation of a new device. It is the atomic force microscope (AFM) JPK NanoWizard 4XP, used for biomechanical scanning combined with an optical fluorescence microscope. This specialized bio-AFM microscope enables local study of the mechanical properties on samples, ranging from tissues or small organisms up to the individual biomolecules. Standard AFM microscopes are not suitable for working with this type of biological samples. However, the new device is adapted to work with biological samples in physiological conditions and additionally provides a significantly greater range of motion, which enables scientists to also study large and fragmented samples. One can investigate mechanical properties of bone sections, plant parts, but also cells in cell cultures. An important area of application is the study of cell adhesion to new types of materials that are being used for the construction of body implants.
Atomic force microscopy is a microscopic technique used since the late 1980s to image surfaces in three dimensions. With this method, scientists study the adhesion of a material, but also its elasticity or plasticity. The image of the surface is assembled gradually, point by point. This method achieves a very high resolution and can display even individual atoms. The AFM technique can be used not only for imaging, but also for forming structures or for processing of surfaces in the nanometer range. AFM microscopes belong to the group of microscopes working with a scanning probe. The interaction between this probe, which is usually a pyramidal tip, and the surface then allows the creation of a topographic image of the sample and also the measurement of its mechanical properties.
"The best instruments are really able to see individual atoms, but this is especially true for research in materials engineering. If we talk about the so-called bio-AFM microscopy, the resolution for biological samples typically begins at the level of the double-helical structure in the DNA molecule and ends at the level of whole cells, cell clusters and tissues. A new trend is the use of AFM in the so-called nanoindentation, where the microscope probe serves as a nanosensor, applying a precisely controlled force to the sample. This experimental approach then enables the study of mechanical properties, such as adhesiveness, elasticity or plasticity. Thanks to the high accuracy of the AFM microscope, it is possible to monitor these properties at the level of individual biomolecules, but of course it is also possible to increase the sample size up to the tissues or small organisms," explains Jan Přibyl, head of the Core Facility Nanobiotechnology.
The main advantage of this microscope is the extended measuring range. Scientists working with large and fragmented samples have been longing for this feature for a while. The scientific potential of the device is greatly increased by expansion modules FluidFM and NanoIndenter Biosoft. FluidFM is a special part of the AFM microscope, where otherwise a full probe contains a microfluidic channel connected to the pump. Such a system can be compared to a nanopipette with extremely precise control not only in terms of movement but also for targeted force interaction. The nanopipette can then be used to picoinject various solutions into individual cells or to extract extremely small volumes at the level of individual cells. Another interesting application is the study of cell adhesion on surfaces, which is a basic parameter for testing new materials with potential use for implant construction. In this process, the cell is aspirated with a nanopipette and the force required to tear it from the surface is monitored. The FluidFM module can also serve as a 3D nanoprinter.
NanoIndenter BioSoft is a modification of the standard indenter for working with biological and very soft samples. The classic indenter is a device based on the linear ejection of a hard tip, which could be described as a needle with a precisely defined tip. During the extension, the studied material is deformed and its mechanical properties are described during the deformation process. However, Indenter was developed primarily for materials research, to study very hard and rigid materials, such as alloys, ceramics, semiconductors, etc. The BioSoft device is the first of its kind that is suitable for working with very soft samples. It is thus possible to study the mechanical properties of hydrogels, cells in cell cultures, tissues, parts of plants, but also bone sections or bacterial biofilms. The device thus suitably complements the results obtained by AFM nanoindentation.
In addition to standard AFM imaging applicable to a wide range of samples, the new instrument will primarily serve scientists studying the pathophysiology of various diseases through changes in the mechanical properties of cells. An indisputable advantage is the possibility of working under so-called semi-physiological conditions, which are very close to physiological conditions. As part of the installation, the Core Facility Nanobiotechnology also organized a series of three workshops, with the aim to familiarize the scientists with the potential of this unique device.
Tweets by CEITEC_Brno