出版社：International Academy of Ecology and Environmental Sciences
摘要：We present here the first description of recorded sexual differences in flight behaviour and space use of lesser kestrel Falco naumanni. Lesser kestrel is a migratory, colonial, small falcon breeding mainly in holes and crevices in large historic buildings within towns and villages, or in abandoned farm houses across the countryside. Using accurate GPS data-loggers, we gathered data on the activities of lesser kestrels in the two of main colonies of lesser kestrels in Italy, i.e. Gravina in Puglia and Altamura (Apulia, Southern Italy) and the surrounding rural areas in a 20-days monitoring during the reproductive period. We tested for sex differences in space use (home range’s circularity ratio) and flight attributes (5-minute flight length, instantaneous speed, distance from nest, flight altitude above ground level) of 9 monitored individuals (4 males and 5 females). We found significant sexual differences for all the observed traits. Our results demonstrate that female lesser kestrels during the monitoring period employed a lower amount of energy in local movements as measured by four flight attributes that resulted significantly different (and lower) than for males. Compact home ranges for females could represent a maximization of the benefit-cost ratio between prospected surface and distance from nest, i.e. the optimal trade-off between foraging requirements (explored surface) and costs in terms of time and energy (distance from nest). On the contrary, males showed a significantly different space use with very elongated home ranges and mean distance from nest almost three times as elevated as females’ one. We argue that the detected sexual divergence was the product of their respective ways to optimize the relationship between resource acquisition and reproductive activity.
