Wednesday, October 20, 2010

Panama's Vultures

The New World Vultures (Cathartidae) are one of the most conspicuous elements of Panama's avifauna... there is always at least one of them within sight field. Misunderstood and usually ignored, they play an important role as scavengers, eating the carcasses of dead animals. They are amazingly adapted for this way of life, and they are so succesfull that most species are essentially aboundant in their own habitat (which includes cities and towns for some species). Sharp eyes and sense of smell, bald heads, effortless long-distant flights, strong gastric juices and to urinate on its legs are just a few of these adaptations.
Of the seven species that compose this family (including two species of extra-limital Condors), four are found in Panama. Of these, the Black Vulture (Coragyps atratus) is certainly the most common. If a panamanian is talking about a Gallinazo or, more commonly, a Gallote; then, he is talking about the Black Vulture. They congregate in incredible huge flocks at their prefered sites, like dumping sites and some beaches, feeding in almost anything they can find. As its name suggest, they are entirely black except for the white primaries which are easily seen in soaring birds.
The Black Vulture is the only member of its genera, the same as the King Vulture (Sarcoramphus papa). This bird is well-named. Not only is the biggest of the vultures (of course I'm not taking into account the condors), it is also quite distinctive from all others due to its mostly white plumage and multicoloured head. Also, it is the first one to eat if there are other vultures' species around a carcass. The numbers of this majestic bird are not even close to that of other species, but anyway it is still common in regions with extensive forest. Despite I have seen this species many times, it is always nice to see it perched (and not soaring as I usually do). This particular individual was taking a sunbath during the first hour of light.
The other two species belong to the genera Cathartes. The most common is the Turkey Vulture (C. aura). The resident subspecies are sedentary birds outnumbered by its black cousins. However, they become aboundant during migration, when most part of the populations breeding in North America fly over the isthmus in an impressive spectacle that marvels both birders and non-birders. The resident group can be distinguished by its pale (white or bluish) nape, and some authors think that they may represent a distinct tropical species... but more studies are needed for sure. At close range, it is obvious why we call them Turkey Vultures... they are pretty evocative of those big game birds worlwide known. In Panama, they are well-known with the local name Noneca; in other regions they are know also as Auras. Young birds exhibit more feathered dark-heads (is the same for all the Cathartes vultures). They have an incredible sense of smell... you can tell by seeing its skull, which have disproportionaly huge cavities to accomodate its sensory organs. Also, they are designed to fly or, more exactly, to soar across huge distances taking advantage of every single breeze, saving as much energy as they can. Its silhouette is distinctive, even from far away!
Finally, the Lesser Yellow-headed Vulture (C. burrovianus) is also pretty common... in the right habitat: swampy savannas and grasslands where they feed mostly on dead fish probably. Despite its commoness, few people is aware of the existence of a yellow-headed (instead of red-headed) vulture, until they get a close look. Then, the bird is impressive, with its rather multicoloured head. One can say that it is beautiful... an adjective not usually used with this family of birds. The Lesser Yellow-headeds usually soar low over the fields, showing its white shafts in the primaries feathers, which separate them from the similar Turkey Vulture. Despite all these vultures occupy different habitats, it is not unusual to see up to three species together at many sites, but more impressive is that, so far, I have seen all the four species together in two places this year. First at El Real airstrip (western Darien province), and then at Flores (southern Veraguas province) where I photographed the King Vulture pictured above. So, always be prepared for the unexpected!

1 comment:

  1. Muy interesante Jan! te felicito!

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