Crested eagle

This species is a large but slender eagle. It measures long and has a wingspan of . A small handful of crested eagles have been weighed and have scaled from . The average weight of crested eagles in Tikal, Guatemala was claimed to be only , with a male reported to weigh and a handful of females . Standard measurements have indicated females are about 14% larger on average than males. , Panama The crested eagle has a large head, an effect enhanced by the often extended feather crest of its name. It has bare legs, with a sizable tarsus length of . The tail is fairly long, measuring in length, in part accounting for the considerably low weights cited for an eagle of this size. ==Distribution and habitat==

It is sparsely distributed throughout its extensive range from northern Guatemala through Belize, Honduras, Nicaragua, Costa Rica, Panama, being now found practically only in the Amazonian basin), and east Andean Ecuador, southeastern Peru, Paraguay and eastern Bolivia to north Argentina. The crested eagle lives in humid lowland forests, mostly comprised by old growth tropical rainforests. They can also range in gallery strips and forest ravines. Over most of the range, sightings of the species are from sea level to . However, in the Andean countries, they appear to be local residents in foothill forests up to elevation or even . They may show some predilection to be near water, including coasts or rivers. ==Ecology==

The crested eagle seems to be a still-hunter, as it has been observed perched for long periods of time while visual scanning the forest around them. The crested eagle may avoid direct competition with the harpy eagle by taking generally smaller prey. However, the crested eagle is certainly a powerful avian predator in its own right and most studies have indicated they are primarily a predator of small mammals. Often reflected in the diet are small monkeys, such as capuchin monkeys, tamarins, and woolly monkeys. Data from the Atlantic Forest of Brazil indicates that small-to-mid-sized monkeys appear to be focused on, either adults of small monkeys like squirrel monkeys and tamarins or small and young specimens of larger species like white-faced sakis and red-faced spider monkeys, with the monkeys attacked estimated to usually weigh from . Other mammalian prey may include numerous arboreal rodents as well as opossums, sloths and kinkajous. Further studies indicate that the crested eagle is specialized to hunt the small to mid-sized monkeys relative to other forest raptors but that the crested eagle preferred to attack the young of even smaller monkey species such as tamarins. In Tikal, the primary prey appeared to be opossums, from tiny mouse opossums to mid-sized Didelphis species, and the largely nocturnally-active prey of crested eagles indicated a deeply searching hunting technique, which overlapped with the black hawk-eagle in the region but not with the region's ornate hawk-eagle, which, in spite of its smaller size, tended to take larger prey and be more opportunistic as well as having a stronger predilection for bird-hunting. Various studies have also pointed to the abundance of snakes (both arboreal and terrestrial varieties with several instances of predation on boas reported) and other reptiles (principally lizards including iguanas) in its prey base, but the relative frequency of different types of prey apparently varies greatly on the individual level and reptiles appear to take a secondary position to mammals. It will also predate on tree frogs. Birds may comprise a larger portion of the diet for crested than they do for harpy eagles. Birds such as jays, trumpeters and guans have been observed to be predated at fruiting trees and male cocks-of-the-rock have been predated while conspicuously performing at their leks. However, dietary studies have indicated birds are even more minor in dietary significance than reptiles. The crested eagle is almost always observed singly or in pairs, being solitary like most raptors. ==Status==

The crested eagle has always seemed to occur at low densities and may occasionally elude detection in areas where they do occur. Though they still have a large distribution, they are currently classified as Near Threatened by the IUCN. The crested eagle is believed to no longer occur in several former breeding areas where extensive forest have been cleared. Data indicates that the species is declining essentially throughout its entire range. ==References==