TY - JOUR
T1 - Experimental evidence for density dependence of reproduction in great tits
AU - Both, C.
N1 - Reporting year: 1998
Metis note: 2398; CTE; PVD; file:///L:/Endnotedatabases/NIOOPUB/pdfs/Pdfs1998/Both_2398.pdf
PY - 1998
Y1 - 1998
N2 - 1. Density dependence of avian reproduction has often been analysed using correlations between annual mean reproductive output and population density. Experiments are necessary to prove that density is the cause of the observed patterns, but so far, three out of four experimental studies do not support a direct causal effect of density on reproduction. 2. This paper presents experimental evidence that reproductive decisions in great tits, Parus major L., are causally affected by breeding density. The breeding density of great tits was manipulated by providing nest-boxes at different densities in an ecologically homogeneous area. 3. Within years the densities in the high and low density plots differed approximately 8-fold. During the 11 years of the experiment, clutch size, nestling mass and the proportion of birds starting a second brood were all lower in the high density plot. In 5 years with equal breeding densities in both parts, clutch size did not differ between the plots. The patterns found were consistent with the density effects as predicted from the non-experimental data. [KEYWORDS: clutch size; density dependence; density manipulation; Parus major; reproduction Flycatcher ficedula-hypoleuca; clutch-size; parus-major; interspecific competition; population fluctuations; food; survival; habitat; fitness; winter]
AB - 1. Density dependence of avian reproduction has often been analysed using correlations between annual mean reproductive output and population density. Experiments are necessary to prove that density is the cause of the observed patterns, but so far, three out of four experimental studies do not support a direct causal effect of density on reproduction. 2. This paper presents experimental evidence that reproductive decisions in great tits, Parus major L., are causally affected by breeding density. The breeding density of great tits was manipulated by providing nest-boxes at different densities in an ecologically homogeneous area. 3. Within years the densities in the high and low density plots differed approximately 8-fold. During the 11 years of the experiment, clutch size, nestling mass and the proportion of birds starting a second brood were all lower in the high density plot. In 5 years with equal breeding densities in both parts, clutch size did not differ between the plots. The patterns found were consistent with the density effects as predicted from the non-experimental data. [KEYWORDS: clutch size; density dependence; density manipulation; Parus major; reproduction Flycatcher ficedula-hypoleuca; clutch-size; parus-major; interspecific competition; population fluctuations; food; survival; habitat; fitness; winter]
U2 - 10.1046/j.1365-2656.1998.00228.x
DO - 10.1046/j.1365-2656.1998.00228.x
M3 - Article
VL - 67
SP - 667
EP - 674
JO - Journal of Animal Ecology
JF - Journal of Animal Ecology
SN - 0021-8790
IS - 4
ER -