A group of researchers from Virginia tech, found that birds living in cities exhibit a higher level of territorial aggression than those birds who were lucky enough or not lucky enough to live in rural areas. In any case it concerns the males singing sparrows, the behavior of which some experts have observed.
photo: Natalia Muslinkina
35 birds, “participated” in the study lived in suburban areas, however, close to the city. They were surrounded by all the city’s characteristic attributes — tall buildings, cars, streetlights, dumpsters, and so on. The other 38 Vorobyov was “the village” residents living in parks, at rivers or on-site farms away from the cities. Specialists tested objectively they divided the birds into “urban” and “rural”, examining satellite images and checking how far each lives from the nearest large and bustling settlement.
To check the level of aggression of birds, experts have found in their habitat dynamics, which are sometimes heard singing with another male — the sparrows had to assume that their territory has been infiltrated by a competitor.
Cost of “urban” singers sparrows to seslichat the voice of the intruder, they began to aggressively flapping their wings and making sounds that these birds mean the threat, then rushed in the direction where he heard music. Of course, the protection of its territory and cared for the sparrows that lived away from the cities, however, they showed significantly less aggression and are not too eager to get into a fight”.
According to the researchers, they found out that living in an urban area birds not aggressive at certain periods of time, but constantly. What exactly is the reason experts say is not ready, but they suggest that anger most likely is not due to stress from noise and lighting, and the fact that the birds really appreciate the urban area, and guard it fiercely because of this. Probably one of the reasons for that may be affordable food in the city dump.