Chicks have a hook on the upper mandible, which disappears by the time of fledging. If there isn’t enough food, the chicks will quarrel, with the hook being used as a weapon, and the smallest chick may even be killed by its larger siblings. If food is plentiful, the parent birds spend more time brooding the chicks, so the chicks are not able to fight.
|Laughing kookaburra (Dacelo novaeguineae). (© LightColourShade. All rights reserved)|
|Laughing kookaburra (Dacelo novaeguineae) front view. (by-nc-nd)|
|Laughing kookaburra (Dacelo novaeguineae) on perch. (by-nc-nd)|
American kestrel (Falco sparverius), or the sparrow hawk, is a small falcon, and the only kestrel found in the Americas. American kestrel hunts by hovering in the air with rapid wing beats or perching and scanning the ground for prey. Its diet typically consists of grasshoppers, dragonflies, lizards, mice, small birds and even snakes. It nests in cavities in trees, cliffs, buildings, and other structures. The female lays three to seven eggs, which both sexes help to incubate. It is commonly used in falconry, especially by beginners.
It is found grasslands, meadows, deserts, and other open to semiopen regions, but they can also be found in both urban and suburban areas. A kestrel's habitat must include perches, open space for hunting, and cavities for nesting (whether natural or man-made). The bird breeds from central and western Alaska across northern Canada to Nova Scotia, and south throughout North America, into central Mexico and the Caribbean. Most birds breeding in Canada and the northern United States migrate south in the winter. American kestrel has a 14-17 year life expectancy, and is able to live in very diverse conditions, ranging from above the Arctic Circle, to the tropics of Central America or elevations of over 4,500 m (14,800 ft) in the Andes Mountains. kestrels can live up to 14–17 years.
|American kestrel (Falco sparverius), Sparrow hawk female.|
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|Great Grey Owl (Strix nebulosa) portrait. (© LightColourShade. All rights reserved)|
|Great Grey Owl (Strix nebulosa). (by-nc-nd)|
Harris's hawk (Parabuteo unicinctus), is a medium-large bird of prey that breeds from the southwestern United States south to Chile and central Argentina.
Harris' hawk is notable for its behaviour of hunting cooperatively in packs consisting of tolerant groups, while other raptors often hunt alone. Harris's hawk's social nature (rather bad luck) which results in easier training has made Harris' hawk a popular bird for use in falconry.
|Harris Hawk (Parabuteo unicinctus) on windowsill. (by-nc-nd)|
Pied crow (Corvus albus), Africa's most widespread member of the genus Corvus, occurs from Sub-Saharan Africa, specifically Senegal, Sudan, Somalia and Eritrea down to the Cape of Good Hope and on the large island of Madagascar, the Comoros islands, Aldabra group islands, Zanzibar, Pemba and Fernando Po. It inhabits mainly open country with villages and towns nearby and is rarely seen very far from human habitation. Pied crows are generally encountered in pairs or small groups, although an abundant source of food may bring large numbers of birds. The species behaves in a similar manner to the hooded and carrion crows. Their menu consists of insects and other small invertebrates, small reptiles, small mammals, young birds and eggs, grain, peanuts, carrion and any scraps of human food and sometimes fruit and even mushrooms. It has been recorded killing and eating roosting bats and is frequently seen scavenging around slaughterhouses in large numbers. The nest is usually built in tall, isolated trees, though sometimes smaller ones are used, depending on availability. The cross supports of telephone poles are also frequently used, and both sexes build the nest. They lay a clutch of 3–6 eggs Incubation lasts 18–19 days and the young are usually fledged by around 45 days. As in all good families both sexes rear the young.
|Pied Crow (Corvus albus) thoughtful. (by-nc-nd)|
|Pied Crow (Corvus albus). (by-nc-nd)|
Turkey vulture (Cathartes aura), aka turkey buzzard (or just buzzard), and in some areas of the Caribbean as the John crow or carrion crow, is the most widespread of the New World vultures which ranges from southern Canada to the southernmost tip of South America. It inhabits a variety of open and semi-open areas, including subtropical forests, shrublands, pastures, and deserts.
Like all New World vultures, it is not closely related to the Old World vultures of Europe, Africa, and Asia. The two groups strongly resemble each other because of convergent evolution; natural selection often leads to similar body plans in animals that adapt independently to the same conditions.
Turkey vulture is a scavenger and feeds almost exclusively on carrion it finds using its keen eyes and sense of smell while flying low enough to detect the gases (ethyl mercaptan) produced by the beginnings of the process of decay in dead animals, preferring those recently dead, and avoiding carcasses that have reached the point of putrefaction. This heightened ability to detect odors allows it to search for carrion below the forest canopy. King vultures, black vultures, and condors, which lack the ability to smell carrion, follow the turkey vulture to carcasses. Turkey vulture arrives first at the carcass, or with greater yellow-headed vultures or lesser yellow-headed vultures, which also share the ability to smell carrion. It displaces the yellow-headed vultures from carcasses due to its larger size, but is displaced in turn by the king vulture and both types of condor, which make the first cut into the skin of the dead animal. This allows the smaller, weaker-billed turkey vulture access to food, because it cannot tear the tough hides of larger animals on its own. This is a shining example of mutual dependence and even collaboration between species.
Turky vultures may rarely feed on plant matter, shoreline vegetation, pumpkin, coconut and other crops, live insects and other invertebrates, and in South America on the fruits of the introduced oil palm. They rarely, if ever, kill prey themselves. Like other vultures, it plays an important role in the ecosystem by disposing of carrion which would otherwise be a breeding ground for disease. The only downside is that their droppings can harm or kill trees and other vegetation.
It roosts in large community groups on dead, leafless trees or man-made structures such as water or microwave towers. Lacking a syrinx—the vocal organ of birds—its only vocalizations are grunts or low hisses. It nests in caves, hollow trees, or thickets. Each year it generally raises two chicks, which it feeds by regurgitation. It has very few natural predators. This vulture is often seen standing in a spread-winged stance. The stance is believed to serve multiple functions: drying the wings, warming the body, and baking off bacteria. It is practiced more often following damp or rainy nights. Like storks, turkey vulture often defecates on its own legs, using the evaporation of the water in the feces and/or urine to cool itself, a process known as urohidrosis. It cools the blood vessels in the unfeathered tarsi and feet, and causes white uric acid to streak the legs. The turkey vulture has few natural predators, such as red-tailed hawks, golden eagles and bald eagles, while eggs and nestlings may be preyed on by mammals such as raccoons and opossums. Its primary form of defense is regurgitating semi-digested meat, a foul-smelling substance which deters most creatures intent on raiding a vulture nest. It will also sting if the predator is close enough to get the vomit in its face or eyes. Its life expectancy in the wild is about 16 years, while in captivity they can live over 30 years.
|Turkey vulture (Cathartes aura), turkey buzzard profile.|
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