Sex-specific effects of size and condition on timing of natal dispersal in kangaroo rats

Andrew J. Edelman

Behavioral Ecology, 2011, vol. 22, issue 4, 776-783

Abstract: The effects of proximal cues in eliciting natal dispersal are predicted to vary between sexes because of differences in reproductive strategies. I examined how body mass and condition affected timing of natal dispersal in male and female banner-tailed kangaroo rats (Dipodomys spectabilis), a species that lacks sex-biased dispersal. I experimentally manipulated cues by providing additional food to a subset of offspring prior to dispersal. All supplemented offspring, regardless of sex, grew faster, were in better condition, and had higher survivorship than unsupplemented offspring. Sons who received food supplements dispersed earlier than unsupplemented sons, indicating that timing of dispersal was related to size and condition. Timing of dispersal in daughters was unaffected by resource supplementation, suggesting that size and condition are less important proximal cues. These sex-specific responses match the intersexual differences in mammalian reproductive strategies and parental investment patterns. My results support the hypothesis that sons remain at the natal territory until a certain threshold of size and condition is reached. Male reproductive success is typically dependent on body size, which affects their ability to find and defend mates. By allowing sons to remain at the natal territory until this threshold is attained, mothers likely increase the fitness of their sons. Female reproductive success is influenced more by securing resources than by body size. Thus, dispersing as early as developmentally feasible would allow daughters to secure an existing burrow system and maximize the time available for caching food prior to their first breeding attempt. Copyright 2011, Oxford University Press.

Date: 2011
References: Add references at CitEc
Citations:

Downloads: (external link)
http://hdl.handle.net/10.1093/beheco/arr050 (application/pdf)
Access to full text is restricted to subscribers.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:oup:beheco:v:22:y:2011:i:4:p:776-783

Ordering information: This journal article can be ordered from
https://academic.oup.com/journals

Access Statistics for this article

Behavioral Ecology is currently edited by Louise Barrett

More articles in Behavioral Ecology from International Society for Behavioral Ecology Oxford University Press, Great Clarendon Street, Oxford OX2 6DP, UK.
Bibliographic data for series maintained by Oxford University Press ().