Noisy miner

The noisy miner (Manorina melanocephala) is a bird in the honeyeater family, Meliphagidae, and is endemic to eastern and southeastern Australia. This miner is a grey bird, with a black head, orange-yellow beak and feet, a distinctive yellow patch behind the eye, and white tips on the tail feathers. The Tasmanian race has a more intense yellow panel in the wing, and a broader white tip to the tail. Males, females and juveniles are similar in appearance, though young birds are a brownish-grey. As the common name suggests, the noisy miner is a vocal species with a large range of songs, calls, scoldings and alarms, and almost constant vocalisations, particularly from young birds. One of four species in the genus Manorina, the noisy miner itself is divided into four subspecies. The separation of the Tasmanian M. m. leachi is of long standing, and the mainland birds were further split in 1999.

Found in a broad arc from Far North Queensland through New South Wales and Victoria to Tasmania and southeastern South Australia, the noisy miner primarily inhabits dry, open eucalypt forests that lack understory shrubs. These include forests dominated by spotted gum, box and ironbark, as well as in degraded woodland where the understory has been cleared, such as recently burned areas, farming and grazing areas, roadside reserves, and suburban parks and gardens with trees and grass, but without dense shrubbery. The density of noisy miner populations has significantly increased in many locations across its range, particularly in human-dominated habitats. The popularity of nectar-producing garden plants, such as the large-flowered grevilleas, was thought to play a role in its proliferation, but studies now show that the noisy miner has benefited primarily from landscaping practices that create open areas dominated by eucalypts.

Noisy miners are gregarious and territorial; they forage, bathe, roost, breed and defend territory communally, forming colonies that can contain several hundred birds. Each bird has an 'activity space', and birds with overlapping activity spaces form associations called 'coteries', which are the most stable units within the colony. The birds also form temporary flocks called 'coalitions' for specific activities, such as mobbing a predator. Group cohesion is facilitated not only by vocalisations, but also through ritualised displays, which have been categorised as flight displays, postural displays, and facial displays. The noisy miner is a notably aggressive bird, so that chasing, pecking, fighting, scolding, and mobbing occur throughout the day, targeted at both intruders and colony members.

Foraging in the canopy of trees, on trunks and branches, and on the ground, the noisy miner mainly eats nectar, fruit, and insects. Most time is spent gleaning the foliage of eucalypts, and it can meet most of its nutritional needs from manna, honeydew, and lerp gathered from the foliage. The noisy miner does not use a stereotyped courtship display, but copulation is a frenzied communal event. It breeds all year long, building a deep cup-shaped nest and laying two to four eggs. Incubation is by the female only, although up to twenty male helpers take care of the nestlings and fledglings. Noisy miners have a range of strategies to increase their breeding success, including multiple broods and group mobbing of predators. The noisy miner's population increase has been correlated with the reduction of avian diversity in human-affected landscapes. Its territoriality means that translocation is unlikely to be a solution to its overabundance, and culling has been proposed, although the noisy miner is currently a protected species across Australia.

## Taxonomy

English ornithologist John Latham described the noisy miner four times in his 1801 work Supplementum Indicis Ornithologici, sive Systematis Ornithologiae, seemingly not knowing it was the same bird in each case: the chattering bee-eater (Merops garrulus), black-headed grackle (Gracula melanocephala), hooded bee-eater (Merops cucullatus), and white-fronted bee-eater (Merops albifrons). Early notes recorded its tendency to scare off prey as hunters were about to shoot. It was as the chattering bee-eater that it was painted between 1792 and 1797 by Thomas Watling, one of a group known collectively as the Port Jackson Painter. John Gould treated the name Merops garrulus as the original description, and renamed it Myzantha garrula in his 1865 work Handbook to the Birds of Australia, giving it the common name of garrulous honeyeater, and noting the alternate name of chattering honeyeater. He noted the colonists of Tasmania called it a miner, and aboriginal people of New South Wales called it cobaygin. Que que gang was a local aboriginal name from the Blue Mountains.

In the early 20th century, Australian ornithologists started using the name Manorina melanocephala instead, because it was listed first by Latham in 1801. This usage did not follow the letter of the International Code of Zoological Nomenclature, and in 2009 the International Commission on Zoological Nomenclature conserved the current name by formally suppressing the name M. garrula. The species name melanocephala is derived from the Ancient Greek words melas 'black', and kephale 'head', referring to its black crown. Other common names include Mickey miner and soldierbird. Four subspecies are recognised, including subspecies leachi found in eastern Tasmania. The mainland population was split into three subspecies in 1999 by Richard Schodde—titaniota from Cape York Peninsula in Queensland as far south as Mareeba, lepidota from central Queensland and inland New South Wales west of Nyngan, and the nominate subspecies melanocephala from southeastern New South Wales, Victoria, and southern South Australia. There are broad zones where birds are intermediate between subspecies. Further study is required to settle the taxonomic status of these populations.

The noisy miner is one of four species in the genus Manorina in the large family of honeyeaters known as Meliphagidae. The other three species of the genus Manorina are the black-eared miner (M. melanotis), the yellow-throated miner (M. flavigula), and the bell miner (M. melanophrys). One of the most obvious characteristics of the genus is a patch of bare yellow skin behind the eyes, which gives them an odd 'cross-eyed' look. Within the genus, the noisy, black-eared and yellow-throated miners form the subgenus Myzantha. The noisy miner occasionally hybridises with the yellow-throated miner. Molecular analysis has shown honeyeaters to be related to the Pardalotidae (pardalotes), Acanthizidae (Australian warblers, scrubwrens, thornbills, etc.), and the Maluridae (Australian fairy-wrens) in the large superfamily Meliphagoidea.

## Description

### Appearance

The noisy miner is a large honeyeater, 24–28 centimetres (9.4–11.0 in) in length, with a wingspan of 36–45 centimetres (14–18 in), and weighing 70–80 grams (2.5–2.8 oz). Male, female and juvenile birds all have similar plumage: grey on the back, tail and breast, and otherwise white underneath, with white scalloping on the nape and hind-neck, and on the breast; off-white forehead and lores; a black band over the crown, bright orange-yellow bill, and a distinctive patch of yellow skin behind the eye; a prominent white tip to the tail; a narrow olive-yellow panel in the folded wing; and orange-yellow legs and feet. A juvenile can be distinguished by softer plumage, a brownish tinge to the black on its head and the grey on its back, and a duller, greyish-yellow skin-patch behind the eye.

The noisy miner is similar in appearance to the yellow-throated miner and the black-eared miner; it has a dull white forehead and a black crown, while the others have grey heads.

#### Geographical variations

Size variation in the noisy miner over its range follows Bergmann's rule; namely, birds tend to be larger where the climate is colder. Adults from central-eastern and northern Queensland tend to have little or no olive-yellow edging to the feathers of the back and wings, and have a wider white fringe on the feathers of the hind-neck and back, giving birds from Queensland the appearance of having more distinctive scalloping than other populations. Wing length generally increases with latitude, yet M. m. leachi has measurably shorter wings than the nominate race, although no significant difference in wing length was found in a study comparing populations north of 30° S and south of the Murray River. The subspecies leachi also has finer scalloping on the hind-neck than the nominate race, a more intense yellow tinge to the wing panels, and a slightly broader off-white tip to the tail.

The far north Queensland subspecies titaniota has a shorter tail, paler crown, larger yellow skin-patch, and paler upper parts without the yellow-olive of the nominate race; and lepidota, found in western New South Wales, is smaller than the nominate race with a black crown, and darker, more mottled upperparts.

### Vocalisations

As the common name suggests, the noisy miner is an unusually vocal species. Previously known as the garrulous honeyeater, it has a large and varied repertoire of songs, calls, scoldings, and alarms. Most are loud and penetrating, and consist of harsh single notes. It has two broad-frequency alarm calls that are used when mobbing intruders into their territory, or when predators (including humans) are sighted; and a narrow-frequency alarm call that is primarily used when airborne predators are seen, such as the brown falcon (Falco berigora), or other large flying birds, including the Australian magpie (Gymnorhina tibicen) and the pied currawong (Strepera graculina). The aerial predator alarm call is a series of high-pitched, slurred whistling notes. The broad-frequency alarm calls are a series of 'churr' notes, low-pitched and harsh, occurring at low and high levels of intensity. The narrow-band call is used in situations where the bird signals the presence of a predator and restricts information about its own location, while the broad-band alarm is used to attract attention, and can initiate mobbing behaviour. These churring calls vary between individuals, and laboratory tests show that noisy miners can distinguish calls by different birds. Hence, this may be integral to the complex social structure of the species.

Contact or social facilitation calls are low-pitched sounds that carry long distances. 'Chip' calls are given by individual birds when foraging, and a similar call is given by nestlings that call at an increased rate as the mother approaches the nest. Where there is a high level of social activity, such as during territorial disputes with conspecifics, calls are a series of quick, regular, single notes. The noisy miner has a mating display flight song: a soft warble of low-frequency notes given during short, undulating flights by the male, and responded to by the female with a low-frequency whistle. The noisy miner is found in open woodland habitats, where it is an advantage to call from the air, so as to overcome sound attenuation. Another display call, described as 'yammer', is a rapid rhythmical series of notes that is uttered during open-bill, wing-waving displays. The noisy miner has a song described as the 'dawn song'—a communal song of clear, whistled notes emitted in chorus in the early hours of the morning from May through January. The dawn song, which is also sung at dusk, is audible over long distances and features duets that often involve antiphony.

A nestling begins to give the 'chip' call soon after it emerges from the egg, and it calls frequently for the first two-thirds of the nestling period and constantly for the last third. The call does not vary in the presence of an adult at the nest, so it seems likely that the call is not directed at the adult bird. The nestling becomes silent when an adult gives an alarm call, and makes a squealing sound when the adult delivers food. The begging call of a fledgling is similar to the call of the nestling, but significantly louder and covering a greater frequency range (which may make it more directional). The rate of calling, on average, is 85 to 100 calls in a minute, and in open scrub, the call can be heard up to a kilometre away. Subsong, a juvenile vocalisation comprising elements of various calls, begins to be uttered when the fledgling is around thirty days old.

The noisy miner also produces non-vocal sounds by clicking or snapping its bill, usually during antagonistic encounters with other bird species, or when mobbing a predator.

## Distribution and habitat

The noisy miner is endemic to eastern and southeastern Australia, occupying a broad arc from Far North Queensland where there are scattered populations, to New South Wales where it is widespread and common from the coast to a line from Angledool to Balranald, through Victoria into southeastern South Australia, and eastern Tasmania. Its range in South Australia has been steadily expanding since it was first recorded near Adelaide in the early 1890s. It is sedentary over its entire range. The noisy miner is territorial, and the territory of a colony is aggressively defended—which has led to a significant reduction in avian diversity in areas occupied by the noisy miner, with smaller species excluded.

The noisy miner primarily inhabits dry, open eucalypt forest without understory shrubs. It is commonly found in open sclerophyll forests, including those on coastal dunes or granite outcrops; forests dominated by spotted gum on mountain ridges and exposed slopes; box and ironbark forests on the foothills of the Great Dividing Range; mixed forests of eucalypts and cypress (Callitris); forests dominated by yapunya, mulga, gidgee, brigalow or emu bush; in stands of belah and scattered clumps of boree; on the edges of woodlands of river red gum, including swamp woodlands bordering floodplains, and areas dominated by exotic species, such as European ash and willow. It regularly inhabits degraded patches of forest where the understory has been cleared, including recently burned areas, and modified habitats, such as lightly-timbered farming and grazing areas, roadside reserves, bushland remnants in towns and cities, and suburban parks and gardens with trees and grass, but without dense shrubbery.

The noisy miner has benefited from the thinning of woodland on rural properties, heavy grazing that removes the understory, fragmentation of woodland that increases the percentage of edge habitat, and urban landscaping practices that increase open eucalypt environments. It has been described as a 'reverse keystone' species, as it is colonising an ever-increasing range of human-dominated habitats, and aggressively excluding smaller bird species from urban environments. This phenomenon has been also observed in rural areas. A field study across the South West Slopes of New South Wales showed that the noisy miner's presence corresponded with reduced numbers of insectivorous birds, such as fantails, whistlers, the restless flycatcher (Myiagra inquieta), and other honeyeater species, and that this decrease was most marked in sites with better access to water and nutrients. While it has been hypothesised that the proliferation of large-flowering grevillea cultivars has contributed to the abundance of noisy miners, recent research has identified the proliferation of lightly treed, open areas, and the presence of eucalypt species as the most significant factors in the population increase. Large-flowered grevillea hybrids, such as Grevillea 'Robyn Gordon', can benefit the noisy miner, in that an abundance of resources is usually dominated by larger, aggressive honeyeaters, and a continuous nectar source could provide an advantage for the non-migratory species. A field study in box-ironbark country in central Victoria found that noisy miner numbers were correlated with the occurrence of yellow gum (Eucalyptus leucoxylon), which reliably produces flowers (and nectar) each year. The abundance of the noisy miner is primarily determined by habitat structure.

While the range of the noisy miner has not significantly expanded, the density of the population within that range has substantially increased. High densities of noisy miners are regularly recorded in forests with thick understory in southern Queensland, 20 kilometres (12 mi) or more from the forest/agricultural land edge. Many of these sites have extensive road networks used for forest management, and picnic areas and walking tracks for recreational use, and it has been found that these cleared spaces play a role in the abundance of noisy miners in the forest. There is evidence to suggest that higher road densities correspond with higher noisy miner population levels. Field work in Victoria showed that noisy miners infiltrated anywhere from 150 to 300 m (490 to 980 ft) into remnant woodland from the edges, with greater penetration occurring in less densely forested areas. This has implications for the size of woodland habitat needed to contain miner-free areas—around 36 hectares (89 acres). Revegetation projects restoring buloke woodland, a species of she-oak integral to the survival of the red-tailed black cockatoo (Calyptorynchus banksii), have been interplanted with a nurse species, usually fast-growing eucalypts. Noisy miner populations were more likely in those buloke woodlands where eucalypts had been planted at densities of up to 16 per hectare (6.4 per acre). The presence of noisy miners was accompanied by a substantial difference in number and types of other birds found in the woodland.

## Behaviour

### Social organisation

The noisy miner is a gregarious species, and the birds are rarely seen singly or in twos; they forage, move and roost in colonies that can consist of several hundred birds

Within a colony, a male bird will occupy an 'activity space', which will overlap with the activity spaces of other males. Males with overlapping activity spaces form associations called 'coteries', usually consisting of 10 to 25 birds. Coteries are the most stable unit within the colony. The birds also form temporary flocks when engaged in the same activity. These flocks, called 'coalitions', usually comprise five to eight birds, although coalitions of up to 40 birds can occur when mobbing a potential predator. Membership of the coalition changes frequently as individuals leave the group as it passes beyond the boundary of their activity space, or the activity ends or changes, as when the breeding season begins. Females use activity spaces that overlap with those of male birds, but not other females, so that females will join coalitions with males in their area, but only rarely will there be more than one female in the coalition. The exclusivity of female activity spaces leads to young females being driven out of the colony in which they were born, and also makes it difficult for them to gain a place in a new colony. A study of banded nestlings that survived in one colony until the next breeding season, found that they were all male birds, suggesting that all female nestlings had died or left the colony. Emigration of males does not seem to occur until the population density of the colony reaches a critical level.

Looking after the young is communal, with males of the coterie bringing food to the nestlings and removing faecal sacs. Communal feeding increases after fledging, when males from nearby coteries may even bring food to the young birds, if not driven off. Roosting is usually communal, with two to six adults and juveniles roosting in contact with each other, usually near the end of a hanging branch up to 20 metres (66 ft) above ground, within their activity space. They select a new site each evening, often selecting and rejecting several sites, and engaging in aggressive calling and chasing as other birds attempt to join the group. They are often the last birds to roost at night, but appear to sleep soundly, undisturbed by torchlight. Noisy miners drink together at the edge of lakes and dams, and from cattle troughs, often perching on a submerged branch. They bathe by diving head first into water and, when almost totally submerged, flapping their wings vigorously and ducking their heads under the water. They shake excess water off and then fly to a nearby branch to preen. They have been observed using rain- or dew-soaked foliage to bathe, and in dry weather will dust-bathe in dry soil or fine litter, such as grass clippings. Bathing is communal, with birds stimulated to participate by observing others. They are occasionally observed anting.

#### Flock behaviour

The noisy miner engages in most activities in a group. Roosting, foraging, preening, bathing and dust-bathing or anting are communal activities. Dawn song is a communal chorus, particularly during the breeding season. The communal interaction is facilitated by ritualised displays that have been categorised as flight displays, postural displays, and facial displays. In 'long flight' displays, initiated by either male or female birds, groups of up to twenty birds from more than one coterie fly about 40 metres (130 ft) above the canopy for distances of up to 1.5 kilometres (0.93 mi) from the colony, constantly calling and not returning to the colony for about twenty minutes. As they return, the remaining birds show signs of agitation, and sometimes fly up to join them. The 'short flight' display is performed by the male, and may be analogous to the territorial advertising displays of other birds. In a ritualised movement, the noisy miner flies out from a perch across an open area, in a rhythmic undulating pattern, usually calling in flight. At the end of the clearing it turns on an upward swoop and flies silently back to a perch near the starting point. The 'head-up flight' is performed by the female during the nesting period, and may function to attract male helpers. In its most intense form the body and tail are held almost vertically, with legs dangling, and the head held up and back. It is performed by the female when she is selecting the nest site, and when carrying nest-building material, and probably has the function of indicating the location of the nest to other group members.

Postural displays include tall and low poses, pointing, open-bill and wing-waving. The 'tall posture' is used when in close contact with another bird and is a mild threat. The bird holds itself upright with neck and legs stretched, and it faces the other bird. The 'low posture' is a submissive gesture; the bird sits low on a perch with legs obscured by fluffed feathers, and often faces away from the other bird. Fledglings threatened by adult birds will adopt a low posture and open their bill widely. 'Pointing' is a threat display where the bird stretches out horizontally, with feathers sleeked and the bill pointed at the target of the aggression. A bill snap will sometimes accompany pointing. An 'open-bill display' is used by subordinates in encounters between two birds, and by a female on the nest when other birds approach. The 'trident bill display' involves a fully open bill with the tongue raised and protruding, and is a higher-intensity submissive display. 'Wing-waving' is often performed at the same time as an open-bill display. The wings are flexed and held slightly away from the body, and flapped out and up around three to six times. Wing-waving may be accompanied by a yammer call. 'Eagle' displays involve holding the wings and tail spread out, in either a vertical or horizontal position.

Eye displays are made by exposing or covering the bare yellow patch behind the eye—when the feathers are completely sleeked the entire patch is visible, and when they are fluffed the patch is hidden. Eye displays are used in conjunction with postural displays, with the yellow patch fully displayed by dominant birds using threat postures, and immature birds tending to reduce the size of the eye-patch when under attack from other members of the coterie.

On occasion early in the breeding season, mass displays erupt, where twenty or thirty birds perform the various wing-spreading displays, short flights, and constant calling. Displaying birds are attacked by others, and groups of silent but agitated birds watch the interactions. Mass displays are more common in the early morning, can last for up to 40 minutes, and seem to be a combination of sexual and agonistic behaviour.

A 'corroboree' (from the word for a ceremonial meeting of Aboriginal Australians) is a group display, where birds converge on adjacent branches and simultaneously pose hunchbacked, giving wing-waving and open-bill displays, and the yammer call. A corroboree occurs when birds meet after a change in the social environment, such as a bird returning after an absence, or the repulsion of an intruder, or the coming together of different coteries. The corroboree appears to have a bonding function, and may involve all members of a colony.

#### Agonistic behaviour

Described as "always at war with others of the feathered kind" in early notes, the noisy miner is one of the most aggressive of the honeyeaters. Much of the activity within a noisy miner colony is agonistic with chasing, pecking, fighting, scolding, and mobbing occurring frequently throughout the day. The birds unite to attack predators and to defend the colony area against all other species of birds; the species is also highly aggressive intraspecifically.

Female noisy miners are aggressive towards each other, and one cause of a male-biased sex-ratio in colonies may be the females' greater intolerance for each other, driving immatures out of the colony and preventing the immigration of new females. Aggression at the nest is common between males. Adult males begin attacking juveniles when they are around 11 weeks old, and attackers can include males that previously cared for the fledgling. Adult females are less aggressive towards young birds, although mothers do occasionally attack their own offspring, and infanticide has been recorded. There is little male to female aggression other than the 'driving flights' that form part of the mating ritual. In direct attacks on young birds, pecks are directed at the eye-patch. Agonistic behaviour has been observed among nestlings, with aggression intensifying after fledging and at times resulting in the death of a sibling.

The noisy miner colony unites to mob inter-specific intruders and predators. The noisy miner will approach the threat closely and point, expose eye patches, and often bill-snap. Five to fifteen birds will fly around the intruder, some birds diving at it and either pulling away or striking the intruder. The mobbing continues until the intruder remains still, as with a tawny frogmouth (Podargus strigoides), or it leaves the area. Mobbing of snakes and goannas is particularly intense, and most species of bird, even non-predators, entering the territory are immediately chased. The noisy miner has been recorded attacking an Australian owlet-nightjar (Aegotheles cristatus) during the day, grebes, herons, ducks and cormorants on lakes at the edge of territories, crested pigeons (Ocyphaps lophotes), pardalotes, and rosellas. Non-predatory mammals such as bats, cattle, sheep, and wallabies are also attacked, though less vigorously than birds.

Noisy miner attacks are not limited to chasing the intruder, and aggressive incidents often result in the death of the trespasser. Reports include those of two noisy miners repeatedly pecking a house sparrow (Passer domesticus) at the base of its skull and killing it in six minutes; one noisy miner grasping a striated pardalote (Pardalotus striatus) by the wing, while another pecked it on the head until it died; and a sacred kingfisher (Todiramphus sanctus) being chased and harassed for over five hours, and then found dead with a fractured skull.

#### Response to threats

Noisy miners make louder alarm calls in noisier sections of urban environments, such as main roads. The most common initial response to alarm calls is to stay in the area and scan for threats, rather than withdraw. A study conducted in Melbourne and a nearby rural area found that noisy miners in urban areas were less likely to take flight, and when they did they flew shorter distances. It is unclear whether this is an adaptation or that bolder miners had been the ones to settle in the city. A field study in Canberra found that superb fairywrens (Malurus cyaneus) that lived in areas frequented by noisy miners recognised miner alarm calls and took flight, and had learnt to ignore their non-alarm calls, while those that live in areas not frequented by noisy miners did not respond to miner alarm calls. This suggests that the species has adapted and learnt to discriminate and respond to another species' vocalisations.

### Breeding

The noisy miner does not use a stereotyped courtship display; displays can involve 'driving', where the male jumps or flies at the female from 1–2 metres (3.3–6.6 ft) away, and if she moves away he pursues her aggressively. The female may perform a 'bowed-wing display', where the wings and tail are spread and quivered, with the wings arched and the head pointing down. The male may adopt a vertical or horizontal 'eagle display', with wings and tail spread wide and held still for several seconds. Copulation is frequent and conspicuous, with both males and females copulating with several birds, while other members of the colony display or otherwise interfere with the mating pair. Copulation usually occurs on larger, exposed branches close to the nest site and can occur at any time of the day, although slightly more often between 11:00 and 13:00, when communal activities are less frequent. The frenzied courtship activity had led to speculation that the female mates promiscuously to recruit males to help care for the young, but recent genetic testing shows that 96.5% of noisy miner broods result from monogamous mating and that multiple paternity is rare. An observation of banded birds noted that while females copulated repeatedly, it was always with the same male. Mate switching between broods is uncommon, with pairs staying together over several years.

The noisy miner breeds all year long, with most activity from July through November, though the peak period is subject to seasonal variations, with sharp peaks in laying activity when conditions are particularly favourable for raising young. The nest is built in prickly or leafy trees, and the noisy miner is often recorded nesting in eucalypts, and also in wattles, Araucaria, Banksia, Bursaria, Hibiscus, mistletoe, Melaleuca, Pittosporum, Schinus, and jacaranda. It seems to prefer moderately dense foliage for nesting, often near the end of drooping horizontal branches. Support for the nest may be the primary criterion of a suitable nest site, rather than characteristics of the vegetation or location. The female alone builds the nest, which is deep and cup-shaped, woven of twigs and grasses with other plant material, animal hair and spider webs. Occasionally, the nest will include man-made materials such as twine, scraps of material, and tissue paper. It is lined with wool, hair, feathers, flowers or plant down, and padded with a circular mat woven from fibres pulled from the cocoons of the processional caterpillar. The female noisy miner walks around on the ground close to the nest site, picking up material. She gathers material from disused nests of other birds, or dismantles its most recent nest to build a new one. The female completes the nest in five or six days. On average, nests have an external diameter of 15–17.8 centimetres (5.9–7.0 in) and an external depth of 9–11.4 centimetres (3.5–4.5 in). The internal depth of the nest is around 5.5 centimetres (2.2 in).

Eggs vary greatly in size, shape and markings, but are generally elongated ovals; white to cream or pinkish or buff coloured; freckled, spotted or blotched with reddish brown to chestnut or a purplish red, sometimes with underlying markings of violet or purplish grey. The clutch consists of two to four eggs. Incubation is by the female only, and the incubation period is around sixteen days. Hatching is asynchronous, with up to six days being recorded between the hatching of the first and last chicks in a clutch. Young are naked at hatching, and develop a cover of down within two to three days. The fledging period is around sixteen days, and young begin to find food for themselves between twenty-six and thirty days after fledging, but are still regularly fed by adults to thirty-five days. The young leave the nest before they are fully fledged, and only able to fly downwards, and scramble up. They do not go far from the nest, return to it at night, and take some weeks to completely leave the nest. Many fledglings are found on the ground and in low shrubs during this period, where they continue to be cared for until they can make their way up into the trees. These birds are often mistakenly 'rescued'. The fledglings seek out siblings if separated, and huddle together for up to three weeks after fledging.

The noisy miner has some of the largest group sizes of any communally breeding bird, with up to twenty males and one female attending a single brood. Only males help with a nest, and while many birds may be associated with a particular brood, some males devote all their time to a single nest, while others spread their helping efforts across five or six nests. Behavioural evidence and genetic testing indicate that helpers are male offspring of the breeding pair, or full siblings of the male parent. Males nearly always bring food to the nestling singly, and if several arrive at once, one will pass food to a nestling while the others wait. The female leaves the nest quickly when a male bird arrives, and never takes food from one of the helpers. Communal feeding of the young increases after fledging, and the young beg for food with constant 'chip chip' calls and gaping mouths. The female rarely feeds the young birds after they have fledged.

#### Nest predation

Cooperative breeding has been described as a strategy for decreasing nest predation, although one study found no relationship between the number of helpers visiting a nest site and its success or failure. Noisy miners were seen to have a range of strategies to increase their breeding success, including multiple broods, laying eggs early in the season, nesting low in the canopy and group mobbing of predators; these measures did not guarantee against nest failure, due to the diversity of potential predators in the noisy miner's open woodland habitat.

### Feeding

The noisy miner primarily eats nectar, fruit, and insects, and occasionally it feeds on small reptiles or amphibians. It is both arboreal and terrestrial, feeding in the canopy of trees, on trunks and branches, and on the ground. It forages within the colony's territory throughout the year, usually in groups of five to eight birds, although hundreds may gather at a stand of flowering trees, such as banksia. The noisy miner collects nectar directly from flowers, hanging upside down or straddling thin branches acrobatically to access the nectar; it takes fruit from trees or fallen on the ground; gleans or hawks for invertebrates; and picks through leaf litter for insects. It has been recorded turning over the dried droppings of emu (Dromaius novaehollandiae) and eastern grey kangaroo (Macropus giganteus), searching for insects.

In a study of birds foraging in suburban gardens, the noisy miner was seen to spend more time in banksia, grevillea and eucalypt species, and when in flower, callistemon, than in other plants including exotics. Most time was spent gleaning the foliage of eucalypts, and noisy miners were significantly more abundant in sites where eucalypts were present. The noisy miner can meet most of its nutritional needs from manna, honeydew, and lerp gathered from the foliage of eucalypts. Lower numbers of noisy miner were recorded at banksias and grevilleas than other large honeyeaters, such as little wattlebird (Anthochaera chrysoptera) and red wattlebird (Anthochaera carunculata).

Detailed studies of the diet of the noisy miner record it eating a range of foods including: spiders; insects (leaf beetles, ladybirds, stink bugs, ants, moth and butterfly larvae); nectar (from Jacaranda mimosifolia, Erythrina variegata, Lagunaria patersonia, Callistemon salignus, Callistemon viminalis, eucalypts Argyle apple, sugar gum, yellow gum, grey ironbark, and grey gum, Banksia ericifolia, B. integrifolia, B. serrata, Grevillea aspleniifolia, G. banksii, G. hookeriana, G. juniperina, G. rosmarinifolia, and flowering quince); seeds from oats, wheat and pepper tree; fruit from saltbush, mistletoe and crabapple; frogs and skinks; and other matter, such as bread, pieces of meat and cheese, and food scraps.

In the first study to demonstrate different learning techniques in a single species, the noisy miner was found to employ different cognitive strategies, depending upon the resource it was foraging. When searching for nectar, which does not move but is readily depleted, the noisy miner uses a spatial memory-based strategy, identifying characteristics of the environment—a strategy that is efficient in new environments and is not affected by changes in the bird's activities. When searching for invertebrates, it appears to employ a different strategy based on learned rules of insect movement (they improve at finding invertebrates with practice). The two different strategies imply the existence of adapted cognitive mechanisms, capable of responding appropriately to different foraging contexts.

## Conservation status

Abundant throughout its significant range, the noisy miner is considered of least concern for conservation, and its extreme population densities in some areas actually constitute a threat to other species. The strong correlation between the presence of noisy miners and the absence of avian diversity has been well documented. The role played by the noisy miner in the steep decline of many woodland birds, its impact on endangered species with similar foraging requirements, and the level of leaf damage leading to die-back that accompanies the exclusion of insectivorous birds from remnant woodlands, means that any strategy to restore avian diversity will need to take account of the management of noisy miner populations. Some habitat restoration and revegetation projects have inadvertently increased the problem of the noisy miner by establishing the open eucalypt habitat that they prefer. A focus of many regeneration projects has been the establishing of habitat corridors that connect patches of remnant forest, and the use of eucalypts as fast-growing nurse species. Both practices have sound ecological value, but allow the noisy miner to proliferate, so conservation efforts are being modified by planting a shrubby understory with the eucalypts, and avoiding the creation of narrow protrusions, corners or clumps of trees in vegetation corridors. A field study conducted in the Southern Highlands found that noisy miners tended to avoid areas dominated by wattles, species of which in the study area had bipinnate leaves. Hence the authors proposed that revegetation projects include at least 15% Acacia species with bipinnate leaves if possible, as well as shrubby understory plants.

Translocation of noisy miners is unlikely to be a solution to their overabundance in remnant habitats. In a Victorian study where birds were banded and relocated, colonies moved into the now unpopulated area, but soon returned to their original territories. The translocated birds did not settle in a new territory. They were not assimilated into resident populations of miners, but instead wandered up to 4.2 kilometres (2.6 mi) from the release point, moving through apparently suitable habitat occupied by other miners—at least for the first 50 days following translocation. Two birds with radio tracking devices travelled 18 kilometres (11 mi) back to their site of capture. Although noisy miners are protected across Australia, and a permit is required to cull them, culling has been proposed as the most humane and practical method of reducing their impact, particularly where combined with rehabilitation of the habitat to suit a wider variety of bird life. An unsanctioned cull took place on private rural property over 1991 and 1992, which, combined with extensive and dense plantings of native trees, reportedly resulted in an increase in species diversity.

Bird in the honeyeater family from eastern Australia

Taxa named by John Latham (ornithologist)


Marie Sophie Hingst

Marie Sophie Hingst (20 October 1987 – 17 July 2019) was a German historian and blogger living in Ireland who falsely claimed to be descended from Holocaust survivors. Born in Wittenberg to a Protestant family, she fabricated a Jewish background and sent documentation for 22 misrepresented or non-existent relatives, who she claimed were Holocaust victims, to the official memorial Yad Vashem. Hingst maintained the blog Read On, My Dear, Read On, where she wrote about her supposed Jewish background and identity, along with her experiences as a German expatriate in Ireland; the blog received hundreds of thousands of views, and she was awarded "Blogger of the Year" in 2017 by the Die Goldenen Blogger [de] (Golden Bloggers) association.

Throughout her life, Hingst falsified much of her background, connections, and achievements. She claimed to have a background in sex education, having purportedly founded a hospital in New Delhi and worked in sex education outreach to refugees in Germany. Hingst used her fraudulent credentials to receive awards and recognition; alongside her "Blogger of the Year" recognition, she wrote for the German newspaper Die Zeit, was one of the winners of the 2017 Financial Times Future of Europe project, and held positions of prestige in Jewish communities across Europe. In June 2019, the Der Spiegel journalist Martin Doerry [de] exposed Hingst's claims as false with the assistance of a team of historians and archivists. She was castigated in the German media, leading to the destruction of her reputation.

Hingst was found dead in her apartment on 17 July 2019 at the age of 31. Her fraud and suicide attracted attention across Europe. German and Irish coverage of Hingst differed, with German coverage focusing on the extreme sensitivity of the subject she had lied about and how she should have been stopped earlier, while Irish coverage focused on her mental health and accused Doerry of ignoring her vulnerability. She was compared to other women who had been uncovered as misrepresenting their backgrounds, such as Anna Sorokin and Rachel Dolezal; the particular similarity between Hingst and Dolezal, as people who claimed to have faced ethnic discrimination, sparked discussion of the role of identity politics.

## Early life and career

Marie Sophie Hingst was born 20 October 1987 in Wittenberg, a town in Saxony-Anhalt in what was then the German Democratic Republic (present-day eastern Germany). She grew up in a college-educated family from a Protestant Christian background; her grandfather was a pastor. Hingst attended high school in Dessau and studied history in Berlin, Lyon, Los Angeles, and eventually Dublin, where she moved in 2013. She attended Trinity College Dublin, where she completed a PhD in history; from 2015 to 2017, she was a fellow at the Trinity Long Room Hub Arts and Humanities Research Institute. In 2013, she founded the blog Read On, My Dear, Read On, where she wrote about her life as a German expatriate in Ireland and her purported Jewish background and identity. Der Tagesspiegel reported in June 2019 that it had 240,000 "regular readers", and Hingst was awarded "Blogger of the Year" in 2017 by the Die Goldenen Blogger [de] (Golden Bloggers) association.

Hingst had no Jewish ancestry on either side of her family. She claimed her mother was a French-Israeli Médecins Sans Frontières worker who committed suicide when Hingst was 16, and that her Gentile birth mother was her stepmother. She additionally constructed a Jewish background for her paternal grandparents, describing them as Holocaust survivors whose parents perished in the genocide. Hingst reported 22 alleged Holocaust victim relatives to Yad Vashem, Israel's official Holocaust memorial; most of these people were later determined to have never existed, and the remainder to not have been persecuted or killed in the Holocaust. According to later reports, she constructed this backstory shortly after her move to Dublin.

The contents of Read On, My Dear, Read On detailed this supposed family history. Hingst claimed that her paternal grandparents were each the sole survivors of their families; her grandfather was purportedly the youngest of five sons, and her grandmother the youngest of five daughters, both of whom lost their parents and older siblings in Auschwitz. She gave specifics of when many of her relatives had been murdered that contradicted historical dates, such as reporting the deportation of her great-grandfather and his family as occurring in February 1940, when deportations of Jews to Auschwitz only began in March 1942. Her grandmother reportedly ran yearly summer teaparties for fellow Auschwitz survivors in Germany, which Hingst, as a child, arranged invitations for and sat in on to listen to the narratives of the guests. This backstory was not the only focus of the blog. When the Turkish-German journalist Deniz Yücel was imprisoned in Turkey, Hingst sent him daily postcards expressing her support. She posted scans of each postcard on Read On, My Dear, Read On, and kept copies for herself, which she was able to give to Yücel after his release.

As well as constructing a backstory of descent from Holocaust survivors, Hingst fabricated several life accomplishments. She stated on her blog that in 2007, at the age of 19, she had founded a hospital in New Delhi that treated patients and provided sex education. This purported accomplishment led to her writing for Die Zeit about her experiences under the pseudonym Sophie Roznblatt. Her purported experiences providing sex education included working as a consultant at a doctor's office in Wittenberg, where she specialized in responding to anonymous sexual education questions from refugees. These claims were repeated uncritically by sources such as the feminist theory book Rape: From Lucretia to \#MeToo by Mithu Sanyal, published in 2019 by Verso Books.

In addition to her "Blogger of the Year" award and Die Zeit publication, Hingst was awarded a winner of the Financial Times Future of Europe project in 2017. Her winning essay, "Europeans should not abandon a collective identity", was published on the website. In her acceptance speech, she referred to her Jewish family. At various points, she was a panel moderator for meetings of the Memorial to the Murdered Jews of Europe, a member of Trinity College's Jewish Society, and an employee at the Selma Stern Center for Jewish Studies Berlin-Brandenburg [de]. In 2018, Hingst started a viral Twitter hashtag called \#KunstGeschichteAlsBrotbelag ("art history on a sandwich"), based around replicating famous artworks and historical photographs with food. Following the hashtag's popularity, she published a photo-book on the subject with DuMont Buchverlag [de] in March 2019. The book was described as commercially successful. At the time of the Der Spiegel publication in June 2019, she was working at Intel in Dublin as a self-described "disruptor", a role she ascribed to her success on social media.

## Der Spiegel outing

Suspicions were first raised about Hingst's claims in 2018 by the historian Gabriele Bergner [Wikidata]. Working alongside a lawyer, an archivist, and a genealogist, she created a mailing list examining the details of Hingst's blog posts with other researchers. That December, Bergner contacted Der Spiegel journalist Martin Doerry [de] with her impression that Hingst was misrepresenting her background. Throughout the first half of 2019, research by Bergner, Doerry, and archivists from the Stadtarchiv Stralsund led to the conclusion Hingst's claims of descent from Holocaust survivors were fraudulent.

In June 2019, Doerry published "The Historian Who Invented 22 Holocaust Victims", an exposé of Hingst's claims, on Der Spiegel in German and English. The story chronicled the research on Hingst that found she had falsified her Jewish background, her claims of providing medical treatment in India, and her supposed sex education outreach to refugees in Germany. The Der Spiegel piece was picked up by other news outlets across the DACH countries; Der Tagesspiegel compared her to Russian-American con artist Anna Sorokin, while Neue Zürcher Zeitung discussed the implications of the case for editorial reliability, noting her publication in Die Zeit and referencing that Der Spiegel had themselves been taken in by the fraudulent journalist Claas Relotius the preceding year.

Hingst took down her blog and retained legal counsel, who made a statement to the press that Read On, My Dear, Read On "claimed a significant degree of artistic freedom". In a statement to Trinity's student newspaper The University Times, she "strongly den[ied] all accusations" by Der Spiegel and said she had "never falsified anything". Die Zeit retracted her article; other organizations that had granted her platforms, such as Südwestrundfunk and Deutschlandfunk Nova, similarly retracted support of her. She was stripped of her Goldene Blogger prize. A German Wikipedia article was created, describing Hingst as a "blogger and fraudster".

After Doerry's piece was published in Der Spiegel, Derek Scally [Wikidata] of The Irish Times interviewed Hingst with a view towards publishing an article on her. Scally found Hingst emotionally distressed and struggling to handle the negative attention placed upon her by the international coverage of her fraud. He described her as "agitated and wounded, yet intelligent and even humorous"; she expressed her deep distress at the Der Spiegel article, describing herself as feeling "skinned alive", and continued to hold to the background and accomplishments she had presented on her blog despite the evidence to the contrary. Scally informed his employers and Doerry that he was uncomfortable writing about Hingst for The Irish Times; he feared further publications would jeopardize her mental health, and worried he might be the last person to see her alive.

## Death and aftermath

Hingst was found dead in her Dublin apartment on 17 July 2019 at the age of 31. Her death was ruled a suicide.

Weeks after her death, Scally published an article for The Irish Times on his interview and interactions with her mother Cornelia leading up to her death. Cornelia described her daughter as possessing "many realities, and I only have access to one". Doerry spoke to The Irish Times under the promise his statements would not be published; he instead dictated a one-line statement that "Der Spiegel will not comment on the article and regrets the death". Doerry soon after published "Why I Was Right to Report on Marie Sophie Hingst's Lies" for Der Spiegel, where he analysed Hingst's death and the public reaction and concluded his reporting was necessary to prevent a "mockery" of Holocaust victims.

### National differences

The difference between the Irish and German coverage of Hingst's fraud and death attracted media attention across Europe. Jennifer McShane, writing for the Irish IMAGE Magazine, criticised Der Spiegel for apparently failing to recognize Hingst's mental distress while describing Scally's piece for The Irish Times as "compassionate and moving". Avner Ofrath [Wikidata], a scholar of Mediterranean Jewish history at the University of Bremen, wrote about Hingst for the Switzerland-based European Journalism Observatory. He highlighted the enormity of Hingst's fraud, criticising Anglophone writers who attacked the severity of the German coverage for not realizing how offensive her claims were in Germany. Ofrath particularly spoke against commentators who had ascribed Doerry's coverage of the case in part to having lost relatives of his own in the Holocaust, describing the attempts to draw such links as "reveal[ing] an astonishing lack of sensitivity". Annika Schneider of Deutschlandfunk summarized the different Irish and German perspectives on the case as the German media focusing on how Hingst should have been stopped from her fraud, while the Irish media focused on her as a person and the intensity of her psychological distress.

### Journalistic ethics

The coverage of Hingst's life and death raised questions of journalistic ethics. In response to Scally's determination to remain in contact with Hingst's mother after the interview, the German professor of journalism Klaus Meier [de] lauded his ethical commitment but deemed it a level of emotional labour that would not be possible for every case. He also discussed the significant concerns raised by reporting on a mentally vulnerable person. In Hingst's case, Meier and Schneider justified these reports in the public interest; Schneider noted that due to the extent of the fraud, it would not have been possible to anonymize the fraudster.

Other discussions of the case revolved around Der Spiegel's own history of fabrication. Claas Relotius had then-recently been fired from the publication for the falsification of at least fourteen articles; critics accused the focus on Hingst of being an attempt to launder the magazine's image. Doerry responded to these challenges by noting the prior researchers who had also uncovered her fraud, and said he specifically had been sought out for his previous work on similar cases. Relotius had himself been the subject of arguments that the perpetrators of such fraud cases are unable to withstand the criticism they receive when uncovered. Christian Vooren, writing for Der Tagesspiegel, compared their situations in his obituary for Hingst; he similarly felt that the nature of the situation made reporting necessary, but quoted Cornelia Hingst's accusation that Doerry had not "seen the person behind the facts" when writing his exposé.

Deniz Yücel, a Turkish-German journalist who spent 336 days incarcerated in Turkey under suspicion of espionage, was in contact with Hingst via postcards during his imprisonment. Following her suicide, he wrote in a column for Die Welt that Doerry had contacted him during the research into her fraud. Yücel admitted that the severity of the situation forced him to reconsider his prior opinions of her, but felt critical of Doerry's attitude towards the situation and accused him of lacking empathy. Doerry reportedly disapproved that Yücel still sympathized with Hingst and expressed gratitude for her outreach to him; Yücel, for his part, felt that Doerry seemed overly enthusiastic about the case and narrow-mindedly focused on "exposing" Hingst's fraud.

In a column for Süddeutsche Zeitung, Carolin Emcke was critical of the German coverage while simultaneously recognizing the co-existing duty of care to Holocaust victims. She posited that the situation had no easy outcomes, being deeply regretful of Hingst's suicide, but also concerned about the harm her fraud had done to living Holocaust survivors and the memory of the victims. Scally and Emcke both attended Hingst's burial, hosted by Lea Rosh, chairwoman of the Memorial to the Murdered Jews of Europe, who wrote an obituary describing Hingst as a close friend who was unable to bear the media "shitstorm".

### Identity

The identity politics element of Hingst's claims has been the subject of discussion. Writing for Die Welt, Anne Waak [de] compared Hingst to Rachel Dolezal, a former activist who falsely claimed to be of African-American descent. Waak posited that both women's frauds were representative of an essentialist understanding of guilt and victimhood. By claiming to be members of marginalized groups, Hingst and Dolezal were able to present themselves as "authentic" experts on discrimination, and speak with a cultural cachet that under identity politics they would not have otherwise received. Ofrath too compared Hingst and Dolezal, but more cuttingly. He referred to Hingst's narrative as "wrought with clichés and basic inconsistencies", and stated it was a low-quality misrepresentation of the European Jewish experience. By contrast, he referred to Dolezal as having a strong commitment to her black identity. From Ofrath's perspective, Hingst had little interest in or knowledge of Jewish life; he took offence at her claims most strongly because of her superficial understanding of European Jewry and lack of significant research into the subject.

Micha Brumlik, the former head of the Fritz Bauer Institute for the History and Impact of the Holocaust [de], juxtaposed Hingst with fraudsters contemporary to the Holocaust, who had claimed to themselves be survivors. He deemed that unlike people who had been alive at the time, direct feelings of guilt and responsibility could not be a factor in her case; instead, she was attempting to escape a generational sense of historic responsibility. He referred to her as possessing "an unconscious will not only to identify with the victims, but to belong to them".

In the years following her outing and death, the identity politics element of Hingst's case kept her prominent in discussions of high-profile fraudsters. The concept of needing to be associated with the "victims" of ethnic discrimination and genocide, rather than the "perpetrators", was compared to cases such as those of Jessica Krug, H. G. Carrillo, Laurel Rose Willson, and Binjamin Wilkomirski. Commentators referred to the sociocultural appeal of situations like Hingst's as being a desire to "unmask" a con artist and discover the underlying desire driving such claims. The nature of such cases has inspired discussion of the nature of identity itself, and the degree to which fraud, obvious or subtle, plays a role in many politically oriented identities.

German hoaxer and blogger (1987–2019)


Mutual Core

"Mutual Core" is a song recorded by Icelandic singer Björk for her seventh studio album Biophilia (2011). It was written and produced by Björk herself, while programming and beats were made in collaboration with Matthew Herbert and the English dubstep band 16bit. "Mutual Core" is an uptempo experimental song. Its music includes Pipe organ, electronica-tinged sounds and features the Choir Graduale Nobili, the choir featured on Biophilia. The song's lyrics are a metaphor for human relationships, compared to the structure of the Earth and Plate tectonics. The song was well received by contemporary music critics, who praised its production and beats, moreover appreciating Björk's voice on the track.

As with all the songs on Biophilia, an app was made for the song, which features a video game in which the player have to move geological layers as an accordion to play chords. Though the song wasn't released as a single, a music video was produced, directed by Andrew Thomas Huang. The video was critically applauded and received further attention when it got projected for one month in Times Square in 2013, and then across the 7 continents. Björk promoted the song by performing it throughout her Biophilia Tour.

Three remixes by Matthew Herbert, 16bit and These New Puritans were released as part of Biophilia Remix Series. The Matthew Herbert's and the These New Puritans remixes were later included on bastards (2012). In July 2012, the online music store Beatport announced a fan contest in which "Mutual Core" had to be remixed, to be released afterwards on a remix package.

## Background

At the end of 2010, Björk confirmed she was working on a new album. In an interview published on Fréttablaðið, the singer stated that the project was midway through the completion and that she hoped to go on tour before the end of 2011. The project was officialised in March 2011, with the announcement of Björk performance at Manchester International Festival. The project, called Biophilia, comprises a series of live performances, a new website, a documentary and a series of apps, besides the release as a music album which is partly composed on an iPad. The Biophilia Tour was said to be touring eight cities for three years and to be including a series of workshops for children in collaboration with local schools. The first details about "Mutual Core" came regarding its app, which was described to allow users to "arrange geological layers to form chords".

"Mutual Core" was written and produced by Björk, while the beat of the song was made in collaboration with Matthew Herbert and 16bit. The song was engineered by Damian Taylor and Sveinn Kjartansson, with mixing provided by Taylor and Björk. "Mutual Core"'s lyrics were inspired by human relationships and by Björk's family decisions, who had to decide where her daughter, Ísadóra, would go to school between New York City and Reykjavík. Björk felt that the song is "the most personal [on the album] for me". David Fricke of Rolling Stone noted that "Björk likens the human emotions – love, physical obsession, changing moods, violent hurt – in songs such as "Mutual Core", "Moon" and "Virus" to natural phenomena: earthquakes, volcanic eruptions, lunar phases and contagious disease".

Three official remixes of the song have been released. The first one was released on Biophilia Remix Series VI on 25 June 2012, and it is a remix by long time-collaborator Matthew Herbert. Björk stated about Herbert's remixes: "He has taken it full on and made it into his version but still true to the heart of the song and, more than once, improved it". RJ Cubarrubia of Rolling Stone commented that the remix "builds slowly with background bleeps and opaque textures before erupting into a cacophonous rumble". The second one is a remix by 16bit, which was released as part of Biophilia Remix Series VII on July 9, 2012. This version had already been released as part of a promo for Icelandair flights, playing the song in flights to Iceland during Björk's concert residency in Reykjavik in Summer 2011. Other two remixes of "Crystalline" and "Sacrifice" were played. The last remix by These New Puritans has been on November 12, 2012 on Biophilia Remix Series VIII. The remix includes samples from the Traditional composition "Funeral Song (Solomon Islands 1978)", as extracted from the album Spirit of Melanesia by David Fanshawe. On October 8, 2012, the track list for bastards was announced, and the Matthew Herbert's and the These New Puritans remixes were included. On late July 2012, Beatport announced a contest in which the participants had to remix "Mutual Core". The winner would have their remix released on One Little Indian Records in a remix package to be sold on the website. The winner was announced on 18 September 2012, as "Breakwave". This remix, later renamed "Waxx Crooks Remix", was released on December 10, 2012.

## Composition

"Mutual Core" is an uptempo experimental song, which displays elements from electro, techno, glitch, breakcore and ambient, and includes also a choral part during the chorus. The rhythm of the song can be roughly divided into two distinct parts: the verses, which feature moderately sparse electronic beats and a time signature of 5/4, and the choruses, which display more upbeat sounds and a 2/4 time signature. According to Mark Diver of BBC Music during the shift from the verse and the chorus the song "slips from blissful ambience into bombastic electronic percussion, leaving the senses reeling, only to fade back into a comforting lilt".

The instrumentation of the verses includes a pipe organ. Sound designer David Paterson described the way Björk wanted the music on "Mutual Core": "Bjork described the sounds she wanted in a way that left it very open to interpretation. With the track "Mutual Core", for example, she described how it was about magnetic attraction – which doesn't really have a sound that springs to mind". Luke Turner of NME noted that "[Björk's] voice cracks against the increasing, insistent power of the electronic rhythms, as if recognising our human insignificance in the face of geology", citing the verse "As fast as your fingernail grows / The Atlantic ridge drifts" as an example, and, on a similar note, Odile De Plas of Télérama found the singer's voice "strong, acrobat, guttural and [...] crystalline".

The musical shift occurs when the singer pronounces the words "Core", during which, as described by Nikki Debben in her essay included in the Manual Edition of Biophilia, the "modality switches from minor to major". The lecturer noted that "the close, dark sound of the verse is partly due to the minor mode which has a flattened third degree, compared to the brighter sound of the chorus in the major mode which has the "normal" third degree of the chord". This part of the song uses a Plagal cadence, which involves a movement "from a chord built on the fourth degree of the scale to one built on the first degree of the scale". The chorus of the song features a vocal crescendo performed by the choir, which juxtaposes with breakcore-influenced beats, which display elements from dub. Chris Chafin of Capital compared the sound of the chorus to the work of The Chemical Brothers and stated that tracks like "Crystalline" and "Mutual Core" recall previous works from Björk's discography, especially Post (1995) and Homogenic (1997).

## Critical reception

The song was generally well received by music critics, who cited it as a highlight of the album. According to Mark Pytlik of Pitchfork, the song "may be the album’s best track overall", citing "its satisfyingly filthy electro skronk", while giving the album an average review; on a similar note, Arnold Pan of PopMatters defined the song as "the album’s most viscerally powerful number" citing that "that’s music that sounds just as at home in the sacred place of a vast cathedral as it is in the virtual vacuum of cyberspace". Gareth James of Clash praised the album and stated that "when the machine-gun beats do break through on "Mutual Core", they're augmented by a hymnal organ riff and a soaring, unprocessed and unleashed vocal which will leave you breathless".

"Mutual Core" was described as "best" and "climactic" by Helen Brown of The Daily Telegraph, which elected Biophilia as the CD of the Week, and "literally volcanic" by Heather Phares of Allmusic. Jim Fusilli of The Wall Street Journal stated that the track is "earthbound". According to the Daily Mirror review, the track "adds angry rebuke and glitchy distorted power chordings to the shimmering, ringing percussion and natural awe that feature on the astonishing tracks "Virus" and aptly named "Crystalline"". Alexis Petridis of The Guardian praised the composition of the album and stated "There’s something audacious and impressive about the way "Hollow" attempts to strike a weird balance between menace and calm, the vocals as lulling as the staccato backing is unsettling. Or "Mutual Core"’s repeated shifts from a wheezing keyboard – it was doubtless built in a laboratory by the provost of the Massachusetts Institute of Technology and professor Brian Cox, but it sounds like a 13th-century portative organ – to electronic bombardment". Möhammed Choudhery of Consequence of Sound analysed the use of Björk's voice in the album, stating:

> Her unique utility of the English language gives her words a quirky, idiosyncratic edge, allowing lines like “if you forget my name, you’ll go astray/ like a killer whale” to ring somehow striking. Said masterstrokes and quirks are well intact here, as is evident in the asteroid-bass volley of "Mutual Core" and lead single "Crystalline"‘s apocalyptical breakbeat coda. Biophilia‘s finest moments are its most subtly captivating, many of which are (admittedly) almost forgettable on first listen. The aforementioned "Mutual Core" and "Crystalline" can be assured a spot on any and all future Best of Björk compilations, compelling in how they blend archaic instrumentation with blistering electronica.

Despite this, some critics dubbed the song as "tedious" and "interesting but not surprising". Andy Gill of The Independent gave a negative review of the album, praising only the choral elements, stating that: "they’re a constant delight as she reflects upon her desire for the "dangerous gifts" of elemental nature, the lightning-flash of creative inspiration ("Thunderbolt"); muses about being a bead threaded upon a DNA chain ("Hollow"); explores the ethically neutral, natural attraction of parasite to host ("Virus"); admires the creative force of volcanic energy ("Mutual Core")".

## App

As with all the songs on Biophilia, "Mutual Core" was released as an app for iPhone or iPad. "Mutual Core" app features a video game in which the player arranges geological layers in the same way as an accordion to play chords. During the verses, the player tries to unite the hemispheres, because the energy keeps them apart while during the chorus the app shifts to a cutaway of a planet, and the player can touch the layers of the planet's interior to open it up and touch the core. The player may also change the resistance of the chords to increase the difficulty. The app was released on October 10, 2011, along with the rest of the apps from Biophilia. On January 17, 2012, Björk uploaded a video tutorial explaining the app on her official YouTube channel, commented also by Biophilia app designer Scott Snibbe. As Björk explains on the video:

> This app is called 'Mutual Core' and it's about taking the tectonic plates and pushing them together with effort until you create a mutual core beneath them. In musicology-wise this is to teach you about chords, and you can use [..] the tectonic plates, the strata inside them, and it sorta operates like accordion so you can change the chords and push them together and [...] create a mutual core.

### Credits

- Björk – creative director
- John Simon, Jr. – creative director, software engineer

Credits taken from "Mutual Core" app.

## Music video

### Background and development

A music video for the song was commissioned by the director of Los Angeles' Museum of Contemporary Art (MOCA), Jeffrey Deitch. The video was first revealed to be in the making in the September 2012 issue of Dazed & Confused, in an interview with director Andrew Thomas Huang. Huang was revealed to be chosen as the director for the video by Björk herself, marking this the first of several future collaborations. Huang said about the making process:

> "There's a lot of volcanic and earthy stuff in the video, we put Björk in quite a few uncomfortable set-ups when we were filming, but she was game for anything. She was a lot of fun and just very warm and trusting."

The director also hinted at a parallelism between the video and its short film Solipsist, which was released weeks before the shooting of "Mutual Core" video: "[The song] is a metaphor between earth’s crust and two people converging, and the effort that it takes, that was also what Solipsist was about, so working together made sense". The video was shot in Reykjavík in over two days. The director wrote the initial treatment for the video after visiting museums in London. The video features a mix of CG pictures and real natural elements, gathered by the team from different location in Iceland. The floating rocks in the video are made from foam and covered in plaster, fossilised barnacles and various textiles, the rock's tongues and the sand are computer-animated; for this reason, the post-production lasted two months. Björk's face motion was tracked in CG for the video, in which it appears to be melt in the rocks. Her costumes were inspired by Thai and Indonesian costumes, while the substance which resembles magma that she appears to spit in the video was a computer-modified mixture of ketchup and cake batter.

A teaser trailer has been released on 5 November 2012. The teaser shows Björk stuck in a bed of quicksand, wearing a blue wig. The video was premiered at an exclusive screening at the MOCA Grand Avenue on November 12, 2012. It was digitally released on November 13, 2012 on MOCA YouTube's channel, MOCAtv, as part of a series of music videos called ART+MUSIC which features collaborations between artists and musicians. The channel also posted a behind-the-scenes video on the same day. The video features glimpses of filming and an interview with the director of the video, who explains the filming process.

### Synopsis

In the beginning of the video, soil crumbles down, as Björk appears, buried to her waist in the sand, wearing a golden dress (by Michael van der Ham), a brooch on her shoulder designed by the singer herself and a blue wig, holding a rock. As she starts singing, she divides the rock into two pieces. As she waves the pieces, the sand around her stirs. She then lays the two pieces on the sand, and they become part of two rock sprites, that come out of the sand and start writhing around Björk, while strata emerges from them. In the end of the first verse, the strata of the two rocky sprites try to unite, as Björk grabs the sand and let it slips out from her fingers. During the second verse other rocks emerge from the sand and revolve around Björk, who dances in the sand. Other rocky sprites spring out of the new rocks and link to the main two, which are still spinning around the singer's head. The two parts are irresistibly attracted to each other and try to unite as they are stroked by Björk. The strata of the rocks morph to form a face, similar to that of the singer. As the chorus begins, Björk disappears in the darkness. The two rocky parts, now united, start to bestir themselves, whilst various rocks on the sand start to erupt. Lava, magma, smoke and fire storm while Björk's face appears in the lava. Every rock erupts noisily, causing a rain of volcanic ash.

The video shifts again to Björk buried in the sand under the rain of ashes. The two pieces of rock appear again, this time each one with a Björk-shaped strata. The strata also sing parts of the song, and two arms come out from the floating rocks and their hands barely brush against each other. The rocks unite once again as the chorus begins for the second time. During this part of the video, images of Björk singing in a smoky setting alternate with more rocks uniting to the main two, while their Björk-shaped strata secrete a substance similar to lava from their mouth. All the rocks are now united, forming a big volcano, whose crater is shaped like two opposite Björk-shaped rocks. The volcano finally erupts in an explosion of magma, while a thunderstorm occurs in the background. The video ends as the volcano fades out and all that remains visible is ash and smoke.

### Reception and accolades

The video was heavily praised by critics. Bob Boilen of What Matters commented that the video is "a bit weird and smartly done". Tom Breihan of Stereogum stated that the video is "a beguilingly strange vision" and that "as the song unfolds, the images reach an explosive conclusion that resembles a fucked-up metal album cover", on a similar note, Gregory Adams of Exclaim! cited the video as "groundbreaking". A poster on The Huffington Post wrote that the video, which he billed as "hypnotic", "takes viewers on a strange spirit quest gone awry". Jonah Bayer of Myspace opined that "Björk is a true artist, and her new video for “Mutual Core” is ample evidence of that". Likewise, Sam Byford of The Verge stated that "Björk has a history of stunning music videos, but she may have outdone herself with this latest effort", while Gary Pini of Paper billed the singer as a "master of both art and music".

Judy Berman from Flavorwire found the video "a precise yet still poetic evocation of the track", while CraveOnline's Johnny Firecloud opined that "In her new video for "Mutual Core", Iceland's queen of bizarre takes her latest single from Biophilia and turns it into an intimate hallucinatory mingling of the elements". Chris Martins of Spin compared the video to the TV series Nova, stating that the video "might be the weirdest NOVA pilot ever created", later adding that Björk "reinvents herself as the freakiest geology teacher the world's ever seen", an expression used also by io9 blogger George Dvorsky, who commented that "this stunning new video for "Mutual Core" makes us wish we had Björk for a geology teacher". Brett Warner of Ology praised the director's work stating that "director Andrew Thomas Huang's gorgeous visuals will adeptly manage to both confuse the hell out of you and absolutely take your breath away". Abdullah Saeed of The Atlantic compared the video to her previous works and commented:

> Back when she first began experimenting with electronic producer Mark Bell on Homogenic, Cunningham style complemented her music perfectly for videos like "All is Full of Love" Now, a decade and a half later, her music explores biology, a discipline naturally interpreted by Huang’s visual sense. ["Mutual Core"] represents a new level of quality and ingenuity from Huang, who seems to be building on his now established visual style.

On 24 December 2012, the video received two nominations at the 2012 Antville Music Video Awards in the categories of Best Art Direction and Best Visual Effects. It went on to win the latter. The video was nominated for the Music Video of the Year category at the 19th Icelandic Music Awards, but lost to "Glow" by Retro Stefson. On 9 April 2013, the video was nominated at the 2013 Webby Awards in the Online Music & Video — Music category. The video won the People's Voice Webby in that category, as voted by the people on the internet, but lose the Webby bestowed by the International Academy of Digital Arts and Sciences to "Fjögur píanó" by Sigur Rós. The video received two nominations at the 2013 UK Music Video Awards for Best Visual Effects in a Video and Best Art Direction in a Video, winning none. However, Huang was nominated for his work in the video as Best New Director and went on to win the award.

### Global projections

In March 2013, an edited version of the video was shown every night as part of a synchronised program on over 15 of the largest digital signs in Times Square, three minutes before midnight, as part of the Midnight Moment, a presentation of the Times Square Advertising Coalition (TSAC) and Times Square Arts. This Midnight Moment presentation is part of the New York City launch of Streaming Museum's Nordic Outbreak, an internationally touring exhibition of leading contemporary Nordic artists. Following the one-month exhibition in Times Square, a series of public programs and exhibitions took place across the city through 6 April at Scandinavia House, One Dag Hammarskjold Plaza, Manhattan Bridge Archway, Big Screen Plaza, Tisch School of the Arts, and an event in the Sky Room at the New Museum. On July 1, 2013, it was announced that the projections would go global, with planned projections to take place throughout the 7 continents, including a screening in the only cinema of Antarctica. Also on tour is a film by David Bates, Jr. that show the projection of the video across the billboards in Times Square. Commenting on the choice of bringing Björk's video projection worldwide, Nina Colosi, founder and creative director of Streaming Museum, stated:

> In the music video Mutual Core directed by Andrew Thomas Huang, Björk is organically part of nature and universe. The human connection to nature is a theme that underpins most of her artistic output. It’s particularly meaningful to bring Björk’s vision to 7 continents because of its relevance to all cultures.

### Credits

- Björk – starring role
- Andrew Thomas Huang – director
- Árni Björn Helgason – producer (Reykjavík unit)
- August Jakobsson – director of photography (Reykjavík unit)
- Gus Olafsson – production designer (Reykjavík unit)
- Frida Maria Hardardottir – hair & makeup artist (Reykjavík unit)
- Laura Merians – director of photography (Los Angeles unit)
- Hugh Zeigler – production designer (Los Angeles unit)
- David Lyons – visual effects executive producer
- Michael Ranger – lead CG supervisor
- Lindsey Fry – lead compositor
- Nico Sugleris – FX technical director
- LARK Creative – director representative

Credits taken from the official music video on YouTube.

## Live performances

Björk premiered Biophilia'''s songs during the Manchester International Festival with a residency commissioned by the Festival itself. The singer played in a circular stage which included custom-made instruments like computer-controlled Pendulum Harps and a Tesla Coil, an instrument called Gameleste, an hybrid between a gamelan and a celesta, and a pin Barrel organ called Sharpsichord. The stage also included a circle of projection screens. During the "Mutual Core" performance, the screen projected images of moving tectonic plates, which Alan Pedder of the website Wearsthetrousers likened to "Jóga"'s music video, while the choir performed a sort of choreography, which included huddling at center stage during the verses and dancing during the chorus. The song was performed on every date of her Biophilia Tour. Her performance was well received by critics, which praised the whole show and project, which was called "ambitious". While reviewing Björk's show at the New York Hall of Science, Will Hermes of the website PembrokeMayball stated that "during 'Mutual Core', she sang of tectonic plates under a circle of projection screens illustrating the phenomena, and licked her lips after a line about how 'the Atlantic ridge drifts' like she could feel that motion tingle beneath her skin".

"Mutual Core" was added to the Vulnicura Tour set lists beginning with Björk's headlining appearance at the Governors Ball Music Festival in New York on 6 June 2015, adding strings to the organ and choir parts of the original arrangement. The song also found its way onto Vulnicura Live, a collection of Björk's favorite performances from her 2015 tour.

## Credits and personnel

- Björk – vocals, songwriter, organ arrangement, beat, programming, choir arrangement, mixing, producer
- 16bit – beat, programming
- Matthew Herbert – beat, programming
- Damian Taylor – engineer, mixing
- Sveinn Kjartansson – engineer

Credits adapted from Biophilia'' album liner notes.

## Official versions

Digital download

- "Mutual Core" – 5:06

Biophilia Remix Series VI

- "Mutual Core" (Matthew Herbert's Teutonic Plates Mix) – 5:10

Biophilia Remix Series VII

- "Mutual Core" (16bit Remix) – 5:22

Biophilia Remix Series VIII

- "Mutual Core" (These New Puritans Remix featuring Solomon Islands Song) – 3:55

Beatport competition winner

- "Mutual Core" (Waxx Crooks Remix) – 4:27