Known as: Crowned Eagle, Crowned Solitary Eagle.
Estimated numbers left in the wild: 350 to 1,500 (difficult to estimate).
Crowned eagles are large predatory birds with slate grey feathers and a visible crest. These birds are 73 to 79 centimetres long, with a wingspan of 170 to 183 centimetres, weighing around 3 kilograms on average. The tail is striped boldly in black and white, though juveniles are duller and have plumage that includes quite a bit of brown.
Diet: The habits of crowned eagles are different from those of many other eagles, including their apparent habit of being most active at dawn and dusk. Though crepuscular, it is sometimes active in the daylight hours, though it appears sluggish during the day much of the time. Crowned eagles eat poisonous snakes and other snakes as one of the mainstays of their diet, with mammals making up another major portion of their prey. Armadillos, monkeys, weasels, rodents, and skunks are all frequent prey of this bird, too. Birds are taken infrequently, with tinamou and monk parakeets being some observed prey items – though domestic poultry is taken sometimes, too. The birds favour dry, open woodland and various kinds of grassland, as long as some trees are available for nesting.
Breeding: The crowned eagle builds a large, conspicuous nest out of sticks, with the platform typically measuring around 1.2 meters in diameter. Reproduction is slow, with only one egg laid during each breeding cycle. The exact timing of breeding and its specific details are uncertain, though eggs were present in some nests during an October survey and young eagles were seen in the same nests the following May. The crowned eagle remains relatively little-studied, due to its remote location and its sparse population.
Location: Crowned eagles live in Argentina, Brazil, Bolivia, and Paraguay. This bird of prey is found mostly in lowland habitats, including scrub-land (a mix of bushes and grass), open woodland, palm savannah, chaco (a hot, semi-arid plain with sparse dry woodland), and campo cerrado (a distinctive South America savannah type).
Threats: Habitat destruction is the biggest threat to the crowned eagle today despite its extensive range. Cattle ranching degrades the raptor’s habitat, especially the intensive type coming into common use in South America today. Invasive grass species, mechanized agriculture, and pesticides are also taking their toll.
The birds are also persecuted to some extent, at least in some countries – for example, dozens are known to have been shot in Argentina during recent years, while nests are sometimes deliberately disturbed or destroyed outright. A few birds are also captured each year to be sold illegally as exotic pets.
Conservation efforts: Argentina and Paraguay have given this bird protected status, though enforcement is always problematic. Hunting the birds is illegal in Brazil also. Some conservation organizations are working to establish ecological corridors in critical regions to lessen habitat fragmentation. There are also well-organized education initiatives, teaching ranchers that the eagles eat dangerous snakes and do not harm calves.
The Peregrine Fund
The Peregrine Fund aims to reverse the current decline in eagle population by conducting research and educating children from rural communities and farmers.