Relative costs of offspring sex and offspring survival in a polygynous mammal.
Costs of reproduction are expected to be ubiquitous in wild animal populations and understanding the drivers of variation in these costs is an important aspect of life-history evolution theory. We use a 43 year dataset from a wild population of red deer to examine the relative importance of two factors that influence the costs of reproduction to mothers, and to test whether these costs vary with changing ecological conditions. Like previous studies, our analyses indicate fitness costs of lactation: mothers whose calves survived the summer subsequently showed lower survival and fecundity than those whose calves died soon after birth, accounting for 5% and 14% of the variation in mothers' survival and fecundity, respectively. The production of a male calf depressed maternal survival and fecundity more than production of a female, but accounted for less than 1% of the variation in either fitness component. There was no evidence for any change in the effect of calf survival or sex with increasing population density.
Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK hannah.froy@ed.ac.uk.
Hannah
0000-0003-2965-3526
H
Froy
Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK.
Craig A
0000-0002-8547-9828
CA
Walling
Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK.
Josephine M
0000-0002-0075-1504
JM
Pemberton
Department of Zoology, University of Cambridge, Cambridge, UK.
Tim H
TH
Clutton-Brock
Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia.
Loeske E B
0000-0001-8588-1123
LE
Kruuk
D000818:Animals; D000831:Animals, Newborn; D003670:Deer / Q000502:physiology*; D005260:Female; D005298:Fertility / Q000502:physiology; D007774:Lactation / Q000502:physiology; D008297:Male; D011156:Population Density; D011247:Pregnancy; D012098:Reproduction / Q000502:physiology; D012606:Scotland; D012737:Sex Factors; D016019:Survival Analysis
Cervus elaphus; cost of reproduction; sex allocation; wild ungulate population