Asio ecuadoriensis

The peculiar limb morphology of A. ecuadoriensis suggests that it had robust and strong limbs well suited to grip prey and restrain it while it struggled. All other material found at the burrow locality, including those of other owl species, shows the signs of erosion caused by strigiform stomach acid, subsequently suggesting that the bones found at the site had been ingested by a large species of owl that likely inhabited the burrow. As the bones of Asio ecuadoriensis are the only ones not showing such signs of erosion, it is very likely that it is the owner of the burrow and by extension fed on the animals whose bones were recovered alongside it. Mammal bones found in the burrow included Cryptotis shrews, rabbits and cricetid rodents, while other owls are represented by the bones of the American barn owl, the burrowing owl and an indeterminate species of pygmy owl. The abundance of owl remains suggests the possibility that Asio ecuarodiensis may have been an owl specialist, or at least heavily incorporated other owl species in its diet alongside mammalian prey.[2]

American owl diversity during the Pleistocene was notably higher than today, including various large sized species found in continental North and South America as well as insular species like those of the Antilles, which coincided with an increased diversity in condors, caracaras and other raptors. One cause for this diversity may be widespread aridification during this time, replacing forested areas with wide open landscapes offering abundant food sources for birds of prey. Although the disappearance of the later can be linked to the extinction of the American megafauna, the disappearance of giant non-scavenging birds is more difficult to explain. One hypothesis states that these large, specialised taxa were deeply affected by the selective pressures following the Pleistocene extinctions and disappeared relatively quickly, in part due to their smaller population density compared to smaller forms.[2]