La Tour du Valat

Institut de recherche pour la conservation des zones humides méditerranéennes

Titre :	Diurnal mass gain strategies and perceived predation risk in the great tit Parus major
Auteurs :	R. Macleod, Auteur ; A. G. Gosler, Auteur ; W. Cresswell, Auteur
Type de document :	Article
Dans :	Journal of Animal Ecology (74(5) SEP 2005)
Article en page(s) :	956-964
Résumé :	1. Individual animals optimize their body mass to enhance fitness and mass is expected to be optimized over both short and long time-scales. On the short time-scale small birds increase mass as they build up energy reserves over each day to avoid starving at night. Theory predicts that starvation risk should be minimized by gaining mass at the start of the day thus insuring against unpredictable food supply later. However, if predation risk is mass-dependent due to reduced escape flight performance, birds should delay mass gain until later in the day to minimize predation risk. 2. Regulation of mass change over longer time-scales has been well documented and a number of studies have been able to show that over weeks, months and years mass is regulated consistent with the starvation-predation risk trade-off being mass-dependent. However, it is crucial to mass-dependent predation theory that it functions over shorter time-scales as well and that birds are able to regulate their diurnal mass gain strategies in response to predation risk. This has not yet been investigated and recent studies of flight performance have been unable to show that small-scale mass change (

Lundi , mardi et jeudi de 9h à 12h et de 13h à 17h00 : ouverture au public ...