O. Olsson et al., Daily foraging routines and feeding effort of a small bird feeding on a predictable resource, P ROY SOC B, 267(1451), 2000, pp. 1457-1461
Citations number
32
Categorie Soggetti
Experimental Biology
Journal title
PROCEEDINGS OF THE ROYAL SOCIETY OF LONDON SERIES B-BIOLOGICAL SCIENCES
According to theory, a small diurnal bird living in a predictable environme
nt should have the highest feeding effort as late as possible in the day in
order to minimize the time it carries large and costly reserves. The feedi
ng effort should also decline with increasing food availability. We tested
both these ideas with the lesser spotted woodpecker (Dendrocopos minor). Fo
r most of the year, this bird feeds on wood-living insects in dead tree bra
nches. This food supply is likely to be highly predictable on a daily scale
. Our results corroborated the theory. We found that the proportion of time
spent actively feeding was lower in the mornings (before noon) than in the
afternoons. We also found that woodpeckers spent less time feeding the hig
her their food availability. However, for a given food availability they sp
ent more time feeding in the afternoons. This supports the idea that feedin
g is less and other activities are more valuable in the mornings given a pr
edictable food resource. This is the first demonstration of daily routines
in small birds concordant with a predictable environment. In spring, males
but not females reduced their feeding time. This difference between the sex
es may be related to their sex-specific reproductive effort.