Costs of reproduction in female moose (Alces alces) as measured by means of phenotypic correlations

Abstract

The costs of pregnancy and lactation in terms of subsequent body growth and fecundity were studied by comparing different reproductive categories of Swedish female moose (Alces alces) during 1989-1992. Non-reproducing females and females that experienced gestation but not lactation were significantly heavier than females in the same reproductive category prior to reproduction. Production of one offspring and subsequent lactation during the summer and early autumn were also associated with an average annual increase in carcass mass, although this was less pronounced than in females that only experienced gestation. By contrast, production of two offspring and successful rearing of both to the autumn resulted, on average, in a reduction of carcass mass (7%) relative to that of females in the same reproductive category prior to reproduction. In female moose, while body growth was affected by the costs of lactation, future fecundity was not. Instead, future fecundity was related most strongly to the number of offspring produced during the current year. This positive association could not be attributed to variation in individual quality in terms of age or carcass mass. The ultimate consequences of reproduction in female moose seem to strongly influence the patterns of growth: adult females will alternate between gain and loss of body mass among years, depending on the number of offspring produced and successfully reared through the lactation phase.

Published in

Canadian Journal of Zoology
1998, volume: 76, number: 1, pages: 187-193
Publisher: NATL RESEARCH COUNCIL CANADA

SLU Authors

• Sand, Håkan

  • Department of Conservation Biology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Zoology
Ecology

Publication identifier

• DOI: https://doi.org/10.1139/z97-181

Permanent link to this page (URI)

https://res.slu.se/id/publ/51307