Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2011 Aug;65(8):1525-1533.
doi: 10.1007/s00265-011-1162-x. Epub 2011 Mar 11.

Age and sex influence marmot antipredator behavior during periods of heightened risk

Amanda J Lea  1 , Daniel T Blumstein
Affiliations

Age and sex influence marmot antipredator behavior during periods of heightened risk

Amanda J Lea et al. Behav Ecol Sociobiol. 2011 Aug.

Abstract

Animals adjust their antipredator behavior according to environmental variation in risk, and to account for their ability to respond to threats. Intrinsic factors that influence an animal's ability to respond to predators (e.g., age, body condition) should explain variation in antipredator behavior. For example, a juvenile might allocate more time to vigilance than an adult because mortality as a result of predation is often high for this age class; however, the relationship between age/vulnerability and antipredator behavior is not always clear or as predicted. We explored the influence of intrinsic factors on yellow-bellied marmot (Marmota flaviventris) antipredator behavior using data pooled from 4 years of experiments. We hypothesized that inherently vulnerable animals (e.g., young, males, and individuals in poor condition) would exhibit more antipredator behavior prior to and immediately following conspecific alarm calls. As expected, males and yearlings suppressed foraging more than females and adults following alarm call playbacks. In contrast to predictions, animals in better condition respond more than animals in below average condition. Interestingly, these intrinsic properties did not influence baseline time budgets; animals of all ages, sexes, and condition levels devoted comparable amounts of time to foraging prior to alarm calls. Our results support the hypothesis that inherent differences in vulnerability influence antipredator behavior; furthermore, it appears that a crucial, but poorly acknowledged, interaction exists between risk and state-dependence. Elevated risk may be required to reveal the workings of state-dependent behavior, and studies of antipredator behavior in a single context may draw incomplete conclusions about age- or sex-specific strategies.

PubMed Disclaimer

Figures

Fig. 1
Fig. 1
Proportion of time allocated to foraging (angularly transformed) following playbacks. Means for each age/sex class are presented with standard error bars
See this image and copyright information in PMC

References

    1. Arenz CL, Leger DW. Antipredator vigilance of juvenile and adult thirteen-lined ground squirrels and the role of nutritional need. Anim Behav. 2000;59:535–541. doi: 10.1006/anbe.1999.1345. - DOI - PubMed
    1. Armitage KB. Yellow-bellied marmot. In: Davies DE, editor. CRC handbook of census methods for terrestrial. Boca Raton: CRC Press, Inc; 1982. pp. 148–149.
    1. Armitage KB. Social and population dynamics of yellow-bellied marmots: results from long-term research. Ann Rev Ecol Evol Syst. 1991;22:379–407. doi: 10.1146/annurev.es.22.110191.002115. - DOI
    1. Bachman GC. The effect of body condition on the trade-off between vigilance and foraging in Belding’s ground squirrels. Anim Behav. 1993;46:233–244. doi: 10.1006/anbe.1993.1185. - DOI
    1. Beauchamp G. What is the magnitude of the group size effect on vigilance? Behav Ecol. 2008;19:1361–1368. doi: 10.1093/beheco/arn096. - DOI