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ABSTRACT Males of polygynous mammals often do not live as long as females and, in some cases, exhibit evidence of earlier senescence. Patterns of DNA methylation (DNAm) have recently been used to predict chronological age in mammals. Whether DNAm also changes as a consequence of survival and senescence is largely untested in wild animals. In this study, we estimate mortality rates using recaptures of 2700 greater spear‐nosed bats,Phyllostomus hastatus, over 34 years and DNAm profiled for over 300 adult bats. In this species, one male typically controls mating access to a group of unrelated females. Bayesian analysis reveals that mortality risk in males is 1.8 times that of females, and comparison of age‐associated differences in DNAm indicates that DNAm changes 1.4 times faster in males than females. Therefore, even though the age of either sex is predicted by a common set of sites, the methylome of males is more dynamic than that of females. Sites associated with sex differences in the rate of DNAm change are sensitive to androgens and enriched on the X chromosome. Sites that exhibit hypermethylation are enriched in promoters of genes involved in the regulation of metabolic processes. Unexpectedly, subordinate males have higher mortality rates than reproductively dominant males and exhibit faster DNAm change than dominants at dozens of sites. Our results reveal that differences in mortality associated with sex and social status are reflected by changes in DNA methylation, providing novel insights into mechanisms of aging and mortality in this and likely other wild animal populations.
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Post-capture age- and sex-specific survival rates of mule deer in Utah, USA
Accurate estimates of mule deer survival are needed to model population dynamics and develop optimal management plans. Survival rates are often estimated using data from radio-collared animals but capture techniques to deploy these collars can risk mortality and injury to the animal. Our objective was to estimate age- and sex-specific survival rates of mule deer in the state of Utah, USA, while also investigating how these rates were affected by capture and handling. We captured 2,977 mule deer throughout the state and fitted them with radio-collars. Using Cox proportional hazard regression, we then estimated survival rates from the collected GPS data. We also examined the effects of age and sex on survival, while accounting for the influence of a variety of other covariates. Finally, we used a model selection framework to evaluate how long survival rates of captured animals were different from those of animals that were not captured. Fawn survival rates were 0.52 (0.45 – 0.60) for females and 0.66 (0.55– 0.79) for males, and overall adult survival rates were 0.76 (0.75 – 0.78) for females and 0.73 (0.70 – 0.77) for males. Survival rates for both sexes varied by age, latitude, and body condition. The negative effect of capture was small and initially disappeared after 3 weeks, but seemed to reappear later, perhaps during periods of high mortality.
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- Award ID(s):
- 2125921
- PAR ID:
- 10548932
- Publisher / Repository:
- American Society of Mammologists
- Date Published:
- Format(s):
- Medium: X
- Location:
- Boulder, CO
- Sponsoring Org:
- National Science Foundation
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