quinta-feira, 26 de dezembro de 2013

Hawk short tail

Hawk short tail

The hawk-of Short-tailed is a accipitriforme Accipitridae family.
His name means the (Greek) buteo = vulture, buzzard; and the (Greek) = brakhus short, short; and gold, with tail oura, tail. ⇒ short tail vulture or "hawk" short tail.
The common names of species in Portuguese, English and Spanish literally translate the meaning of the scientific name. The name means brachyurus short tail; "Brachy" (Latin) is short, flat, whereas "uros" is tail. However, this species has a significantly lower tail to the body compared to other of its kind, and this feature little help in their identification in the field.

It is approximately 35-45 inches long, with females being larger than males.
The course has morpho the tops and sides of the head in the adult black and brown in the immature, lower white-pure parties; the morpho clear immature plumage, the lower parts are well yellowish.
The dark morph has dark plumage, almost black, with darker secondary than primary. Because of this characteristic, has very similar to the vulture-of-head-black silhouette (Coragyps atratus) in flight. Immature morpho dark can present considerable variation in plumage, which can either be mottled white, as completely dark as in adults.
The pattern and number of the tail bars is also variable in birds Florida - USA, especially in immature and there is evidence that it can occur in Brazil (Monsalvo, unpublished data). In addition, the tail may have immature slightly longer than that of adults.
Individuals with melanin plumage

The melanism it is to increase the production of melanin, giving a darker color to the individual. Individuals melanin is usually associated with other individuals of the same species as the melanism not meant associated diseases such as albinism.
The case of predators
For some species of predators, the individuals are called melanin dark morph individuals, dark phase, or the English term "dark morph". In this case, the mutation does not appear random, and it is already established. In the same litter can be melanocytic and non-melanocytic individuals. The predators "morpho dark" have this color for life. The melanism in this case difficult to identify birds in the field, as these have a different color of the original and can be confused with other species.

Although older studies mention a varied diet of reptiles, invertebrates, amphibians and rodents, data subsequently obtained confirmed that the species is specialized predators of birds, showing both morphological adaptations

Habita fields with trees, forested areas permeated open and urban vegetation. It is usually found alone, sometimes in pairs. Tends to go unnoticed due to the fact spend most of the day hovering at high altitude.
Several studies have shown that this species seems to be more common than previously thought. There is also evidence that their populations are increasing because of its adaptability to environmental disruption.
In many regions where were better integrated - in Argentina, the US and Brazil - the morpho dark proved to be the most common form. In addition, observations of Meyer (2004) and Monsalvo (2012) suggest that this form would be genetically dominant to morpho clear. This possible predominance of dark morph could be another cause of this species go unnoticed, since these individuals are easily confused with a vulture-of-head-black (Coragyps atratus), with which usually share the behavioral térmicas.quanto for his capture. Usually capture small birds giving flybys in the treetops. In tropical regions, however, may have a slightly more diversified diet, due to the greater availability of prey.

There are air shows male, accompanied by vocalizations. Nesting on top of trees 12-30 feet tall. The eggs are usually spotted, very variable color. The incubation period is 32 to 39 days. While there is often two eggs, often develops just a puppy. It is unclear precisely how long the chicks remain in the nest, but the period is around five weeks.
In São Paulo-SP were followed reproducing in an urban park since 2008 (Monsalvo, 2012). This fact, hitherto unpublished, denotes a great adaptability of this species to human activity. From the second week of flight, the puppy received the prey in midair. The father (solely responsible for feeding the family) stopped in the air, vocalizing and keeping the position only with subtle movements of the wings and tail, with prey in the grip. When the puppy approached flying low, father let out the prey and the puppy to grab during the fall. The cub was fed until at least 3 months of age, and just left the nest area with 4 months (Monsalvo, 2012). Apparently the chicks remain in the territory of the country until at least 6 months of age, becoming adults with only 2 or 3 years.

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