Age-related reproductive effort and senescence in free-ranging moose, Alces alces

Abstract

A general prediction for aging placental mammals is that they should show a decline in reproductive value, and reproductive effort is therefore predicted to increase with age. To test this, we monitored known-age radio-collared females of a large ungulate, the moose (Alces alces), in a Swedish population. Female moose showed senescence in reproduction (i.e., litter size) from about 12 yr of age. Further evidence of senescence was a decrease in parental care during summer (expressed as increased offspring mortality) with the mother's age. Moreover, aging females facing a declining reproductive value increased their reproductive effort by giving birth to heavier offspring regardless of litter size. A logistic regression model showed that older moose have to give birth to heavier offspring to achieve the same offspring summer survival as that for offspring of younger mothers. This suggests that females increase their reproductive effort (by increasing offspring mass) as they get older. Furthermore, the rather intense harvest in our population may select for an increased reproductive effort in terms of litter size, which furthermore may select for an earlier onset of senescence in reproductive characters and mortality

Published in

Ecology
2001, volume: 82, number: 6, pages: 1613-1620
Publisher: ECOLOGICAL SOC AMER

SLU Authors

• Ericsson, Göran

  • Department of Animal Ecology, Swedish University of Agricultural Sciences
    

• Ball, John

  • Department of Animal Ecology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Environmental Sciences and Nature Conservation

Publication identifier

• DOI: https://doi.org/10.1890/0012-9658(2001)082[1613:ARREAS]2.0.CO;2

Permanent link to this page (URI)

https://res.slu.se/id/publ/6294