It would seem that Bolivian American Kestrels have switched up their diet as a part of adapting to the high-altitude urbanization.
Original Article here:
http://latino.foxnews.com/latino/lifestyle/2015/01/12/4-species-raptors-...
Four different species of raptors have adapted over the past 20 years to living in the Bolivian capital of La Paz, almost 4,000 meters (14,750 feet) above sea level, and could help reduce the city's overpopulation of pigeons, media reports said, citing a new scientific study.
The species are the black-chested buzzard-eagle, the variable hawk, the mountain caracara and the American kestrel, the latter known locally as the killi killi, and their presence has been studied by biologists Enrique Richard and Denise Contreras, the La Razon newspaper reported over the weekend.
The biologists advise promoting the care of these birds, whose process of adaptation to this city high in the Andes has been developing over the last 15 to 20 years, before which they were seen only in rural, non-urbanized areas.
The largest of these birds of prey is the black-chested buzzard-eagle (geranoaetus melanoleucus), whose wingspan measures around 1.86 meters (6 feet) and which, according to the study, has developed an efficient, sophisticated method of hunting from the rooftops of the historic downtown district of La Paz.
The buzzard-eagle chases pigeons and forces them to fly up to some 4,500 meters (13,000 feet) above sea level, where they collapse due to the altitude and the raptor seizes them without difficulty, Enrique Richard said.
The variable hawk, with a wingspan of 1.2 meters (4 feet), also raises flocks of pigeons to capture them, while the mountain caracara with a wingspan of 1 meter (3 1/4 feet) and the American kestrel with a 1/2-meter (1 2/3-foot) wingspan, steal chicks from pigeon nests.
The researchers said the latter species has changed its diet, having previously fed on rodents.
They also stressed the importance of preserving these birds of prey because of their ecological value, since they help control the overpopulation of pigeons in La Paz, which number some 50,000. -EFE