Speed of migratory movements in birds as adaptive behaviour
Zoological Institute, RAS
199034 St.-Petersburg, Universitetskaya nab., 1
e-mail: payevsky@zin.ru; payevsky@yandex.ru
Migration speed of 115 bird species from 35 families of 14 orders was analyzed. The data were collected from published sources based on ringing recoveries. It was found that average speed varies between 10 and 880 km/day, and the maximum speed varies between 30 and 1392 km/day, but in the majority of species the average speed values are in the range of 20-100, and the maximum speed values are in the range of 40 360 km/day There is significant positive correlation between the average and maximum speed. The ratio between maximum and average speed in different species varies significantly, and overall for all birds is 4:1. On average, shorebirds migrate twice as rapidly as passerines, and average speed of the raptors is rather higher than in shorebirds. The species from Turdidae family migrate significantly faster than the species from Fringillidae family, and the latter migrate faster than tits. No significant differences in migration speed were found between the species from Sylviidae and Turdidae families, as well as between Sylviidae and Motacillidae. Significant negative correlation was found between the body mass and average migration speed in the shorebirds, but no relationship between these parameters was found in the passerines. In many bird species, adult birds migrate significantly faster than juveniles, and in some species no difference in speed was found between males and females. In the passerines, the average migration speed is significantly higher among long-distance early-departing nocturnal migrants as compared with the short-distance late-departing diurnal ones. The spring migration speed was much higher than autumn speed, but in some species only. The behavior of migrants at flight and at stopovers is governed by a complex interaction between their species-specific foraging features, weather conditions, and habitat.
