Golden jackal
The golden jackal is similar to the gray wolf but is distinguished by its smaller size, lighter weight, more elongated torso, less-prominent forehead, shorter legs and tail, and a muzzle that is narrower and more pointed. The legs are long in relation to its body, and the feet are slender with small pads. Males measure in body length and females . Males weigh and females weigh . The shoulder height is for both. In comparison, the smallest wolf is the Arabian wolf ("Canis lupus arabs"), which weighs on average .
Reproduction and life cycle of the golden eagle
The golden eagle chick may be heard from within the egg 15 hours before it begins hatching. After the first chip is broken off of the egg, there is no activity for around 27 hours. After this period, the hatching activity accelerates and the shell is broken apart in 35 hours. The chick is completely free in 37 hours. Upon hatching, the chicks are covered in fluffy white down. One day after hatching, chicks will weigh , with an average of . In the first 10 days, chicks mainly lie down on the nest substrate. The eagles are capable of preening on their second day but are continually thermoregulated via brooding by their parents until around 20 days. Within 10 days, the hatchlings grow considerably, weighing around . Around this age, they also start sitting up more. Around 20 days of age, the chicks generally start standing, which becomes the main position over the course of the next 40 days. The whitish down continues until around 25 days of age, at which point it is gradually replaced by dark contour feathers that eclipse the down and the birds attain a general piebald appearance. After hatching, 80% of food items and 90% of food biomass is captured and brought to the nest by the adult male. The adult male golden eagle perch away from the nest for about 74% of the nestling period, whereas females mainly stay on the nest for about 45 days after the first chick hatches. The voice of nestlings advances from a soft "chirp" to a disyllabic "seeir" at around 15 days of age and then to a louder, clearer and conspicuously harsher "psaa " call given from about 20 days of age to as late as several weeks after fledging. From 10 days to 45 days of age, the nestlings eat much more food and grow considerably. Meal size increases throughout the nesting season, the estimated morsel of flesh fed to the young ranged from at hatching to at fledging. The nestling golden eagles start “mantling” over food at around 10–20 days old: when given a food object, they stand over it, wings partially open, tail fanned and head bowed, covering the food item completely. This is believed to be a competitive behavior as it seen only in nests with more than one chick. Within a matter of days, the chicks try to defecate over the edge of the nest but are not competent at it until they are around 20 days old. The average daily food consumption for female nestlings tends to be greater than those in male nestlings. The average food consumption of the nestling sexes averages and per day, respectively, with male nestlings weighing about less than the equivalent-aged females. Despite this, males typically tend to develop sooner and fledge more quickly than the females. The average amount of food brought to the nest daily was notably higher in Idaho and Montana, where an average of and of prey were brought to the nest, respectively, than in Texas, where an average of was brought. For the first 30 days or so, the nestlings are fully dependent on their parents to feed them but after that period, they start standing around the edge of the nest and practice food tearing. When the first chick is an average of 29 days old, the female first start perching off the nest and at 40 days of age, she stops perching on the nest platform. From 50 days onward, dark brown plumage sprouts from the same sockets as the down and plumage changes become more subtle. The feet go from flesh-colored at hatching to grey to black, thence finally to yellow. When they are around 20 days or so old, as the structure of their wing develops, the nestlings start wing flapping and the frequency and intensity of this behavior increases considerably by 40 days old. Fledging occurs at 66 to 75 days of age in Idaho and 70 to 81 days in Scotland.