Találati lista | Tudóstér

001-es BibID:	BIBFORM066150
Első szerző:	Mónus Ferenc
Cím:	Is foraging time limited during winter? : A feeding experiment with tree sparrows under different predation risk / Ferenc Mónus, Zoltán Barta
Dátum:	2016
ISSN:	0179-1613
Megjegyzések:	Small passerines are faced with a trade-off when foraging during winter. Increasing energy reserves makes them more vulnerable to predators, while a low level of reserves exposes them to a high risk of starvation. Whether small birds under these circumstances are allowed to reduce their foraging activity under increased predation risk, for example in feeding sites more exposed to predators, remains controversial in former behavioural and ecological researches. In this study, we investigated the foraging activity of free-living Tree Sparrow Passer montanus flocks feeding on an artificial feeding platform. The predation risk perceived by the sparrows was manipulated by placing the platform either close to or far from a bushy shelter. Foraging activity, assessed as cumulative activity of sparrows per unit time on the platform, did not differ between the low-risk and the high-risk conditions and did not significantly change during the day. Feeding efficiency, assessed as pecking rate, was not either reduced under the high-risk condition. Our results suggest that sparrows were forced to feed almost continuously during the day in order to maintain their preferred level of energy reserves. However, several behavioural changes helped sparrows to adopt a safer foraging policy when feeding far from cover, as we found in another study. Altogether, sparrow flocks feeding far from cover decreased the overall foraging time (the time when any sparrow stayed on the platform) by approximately 20% as compared to the near cover condition. A possible way to maintain the same level of foraging activity despite of the reduction in overall foraging time is discussed.
Tárgyszavak:	Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban foraging activity predation risk time-limited foraging Tree Sparrow
Megjelenés:	Ethology 122 : 1 (2016), p. 20-29. -
További szerzők:	Barta Zoltán (1967-) (biológus, zoológus)
Pályázati támogatás:	T-46661 OTKA K75696 OTKA 4.2.1./B-09/1/KONV-2010-0007 TÁMOP
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
Borító:
Saját polcon: