move on its own. These groups are most often formed by a couple of adults and a juvenile that combine their efforts in search of food. Small birds, such as the Plain-mantled Tit-spinetail also fall prey to them. Lone Caracaras were also recorded to follow human vehicles that would periodically throw out scraps of food. Being opportunistic feeders, they have adapted well to living near humans and are more concentrated near cities where they are more likely to be able to feast on carrion and refuse. Reproduction The Caracara species are unique among the family Falconidae in that they build their own nests of sticks, though these can range from a bare minimum of materials to quite a substantial amount; some nests consist merely of an empty cliff ledge while others are massive weaves of branches. Breeding season is from October to December and the nest will usually contain two eggs, and very rarely three, that hatch in December. The chicks have fledged and are independent by March, though they may stay with their parents for months afterward. Group Foraging It is still unknown why some Mountain Caracaras use a group foraging method to hunt down food. Even though the hunting party may be able to overturn bigger rocks and cover more ground, the prey captured is usually not shared amongst the hunters and usually little to no benefit is received by the youngest in the group. The Caracara that decides on the most likely rock to move is usually the bird who grabs and eats the prey, though if enough food is available, all members could potentially receive a meal at some point during their forage. Vocalizations When group foraging, an adult who finds a rock worth turning over will call out to attract the rest of its nearby party. A flight call has also been recorded. Taxonomy The Mountain Caracara is closely related to the other birds of the genus Phalcoboenus, a group which separated from the rest of the Caracaras around 1.9 million years ago. The White-throated Caracara (Phalcoboenus albogularis) is the Mountain Caracara's closest relative and there have been recordings of hybridization events between the two species. They differ mostly by the colour of their plumage and by their habitat preference. It is supposed that the Phalcoboenus taxa diverged within themselves roughly 0.6 million years ago when there was a large amount of glacial activity in