Strategie di foraggiamento del Chiurlo maggioreNumenius arquata  e differenze di successo alimentaretra sessi in un sito di svernamento dell’Italia centrale

Trotta M.



Abstract:

Foraging strategies of the Curlew Numenius arquata and differences in feeding success between sexes at wintering site in the Central of Italy. The foraging strategies and the difference of feeding success between sexes of the Curlew Numenius arquata were studied in a coastal region of Lazio (Pontine Lakes) in the period 1997-2001 (november to march). This species has been found in different habitats, however the data for this paper was collected in meadow-pastureland habitats. The pecking was the action used more often, the technique of digging and, to a lesser extent, of jabbing, were more effcient, particularly for the capturing of earthworms. The Curlew had a feeding success (prey/minute) on average of 1.41. The females obtained a little more feeding success. Since the bill of the female is considerably longer, this allows them to penetrate more the ground than males, capturing more prey. Whether feeding as single individuals or in small flocks, the foraging success was the same. The larger flocks have been observed in autumn and it appears that when they arrive, they chose areas with high food availability and, once exploited, they move to lesser-quality foraging areas.