Using Theoretical Flight Speeds to Discriminate Birds from Insects in Radar Studies

The condor

Sergio A. Cabrera-Cruz¹ 

关键词: airspeed;    bird migration;    insects;    Isthmus of Tehuantepec;    marine radar;    Mexico;    radar ornithology.;   

DOI  :  10.1525/cond.2013.110181

学科分类：动物科学

来源: Central Ornithology Publication Office

【 摘 要 】

Abstract. Marine radar is a tool widely used in the study of bird migration, but in most cases it cannot identify detected objects to species. For this reason airspeed is used as one of the main criteria to separate birdlike from insectlike targets, but this criterion has not been tested outside the temperate regions where it was developed. We used a theoretical approach for calculating minimum-power speeds (Vmp) and maximum-range speeds (Vmr) of birds and insects to estimate an interval of airspeeds from which an appropriate value of the criterion can be selected and to propose a criterion based on flight speed for the Isthmus of Tehuantepec in southern Mexico. This approach, with data from 36 species of insects and 60 of passerines either known to occur or similar to species occurring in southern Mexico, found that although Vmp of insects and birds overlaps at 5.5 m sec-1, birds generally fly faster than insects. After combining our results with data from the literature, we conclude that the best airspe...

【 授权许可】

CC BY