Socioecological variables predict telomere length in wild spotted hyenas

Abstract

Telomeres are regarded as important biomarkers of ageing and serve as useful tools in revealing how stress acts at the cellular level. However, the effects of social and ecological factors on telomere length remain poorly understood, particularly in free-ranging mammals. Here, we investigated the influences of within-group dominance rank and group membership on telomere length in wild adult spotted hyenas (Crocuta crocuta). We found large effects of both factors; high-ranking hyenas exhibited significantly greater mean telomere length than did subordinate animals, and group membership significantly predicted mean telomere length within high-ranking females. We further inquired whether prey availability mediates the observed effect of group membership on telomere length, but this hypothesis was not supported. Interestingly, adult telomere length was not predicted by age. Our work shows for the first time, to the best of our knowledge, the effects of social rank on telomere length in a wild mammal and enhances our understanding of how social and ecological variables may contribute to organismal senescence.

Individual variation in early‐life telomere length and survival in a wild mammal

“…Similarly, previous studies in birds have shown that higher levels of early‐life competition can accelerate telomere shortening (Boonekamp et al, ; Nettle et al, ), although studies that do not find stressors affecting early‐life telomere length do exist (reviewed in Vedder et al, ). In mammals, studies on social and ecological effects on telomere dynamics are emerging (Cram et al, ; Izzo et al, ; Lewin et al, ; Watson et al, ; Wilbourn et al, ), showing that, for example, socially dominant spotted hyaenas ( Crocuta crocuta ) have longer telomeres (Lewin et al, ) and that meerkat pups experiencing more intense early‐life competition have shorter telomeres (Cram et al, ).…”

“…In mammals, studies on social and ecological effects on telomere dynamics are emerging (Cram et al, 2017;Izzo et al, 2011;Lewin et al, 2015;Watson et al, 2017;Wilbourn et al, 2017), showing that, for example, socially dominant spotted hyaenas (Crocuta crocuta) have longer telomeres (Lewin et al, 2015) and that meerkat pups experiencing more intense early-life competition have shorter telomeres (Cram et al, 2017).…”

“…Nevertheless, early‐life telomere length might be an important predictor of life histories (Monaghan, ; Wilbourn et al, ; Young, ). While studies into the effects of the environment on telomeres are emerging in wild mammals (Cram et al, ; Izzo, Hamer, Bertozzi, Donnellan, & Gillanders, ; Lewin, Treidel, Holekamp, Place, & Haussmann, ), longitudinal studies in wild mammals remain relatively rare (Beirne, Delahay, Hares, & Young, ; Fairlie et al, ). Gaining a better understanding of telomere dynamics, its relationship with survival, and early‐life effects requires more comprehensive longitudinal studies in wild populations.…”

Socioecological predictors of immune defences in wild spotted hyenas

“…Asterisks denote statistically significant differences marked as follows: *P < 0.05, **P < 0.01, ***P < 0.001. Boydston et al 2003) and telomere length (Lewin et al 2015), but prior to this study it was unknown whether rank affects their immune function. Here, we show that rank is a strong predictor of immune defences in wild spotted hyenas, but that neither age nor circulating hormone concentrations were significantly associated with any of the immune defences that we quantified.…”

Telomere dynamics may link stress exposure and ageing across generations

“…In the chickens, these effects are most likely due to exposure while in ovo since offspring received no post-natal care [24]. In birds, recent experimental research during the post-natal period has also demonstrated that exposure to nutritional and social stressors such as being raised in a larger brood or at a lower social rank leads to greater telomere loss [56][57][58].…”