Defying expectations: sex-biased telomere dynamics and extended lifespan in the tropical bat species, Molossus molossus.

Abstract

Telomeres are key biomarkers of cellular ageing, yet their dynamics remain poorly studied in tropical and short-lived bat species. Here, we present the first investigation of telomere length across age in Molossus molossus, a tropical bat historically categorised as the shortest-lived bat on record. Through a multi-year mark-recapture study in Gamboa, Panama, we sampled 492 individuals (n = 317 females, 175 males) and documented a female M. molossus surviving to at least 13 years of age, more than doubling the previously reported maximum lifespan of 5.6 years. Across the population, relative telomere length (rTL) showed no overall decline with age. However, sex-specific models revealed clear divergence: males tended to have longer rTL than females but showed significant age-related shortening, whereas females exhibited stable rTL across the observed age range. The pattern of telomere stability in females aligns closely with results observed in long-lived bats of the Myotis genus while male-specific attrition suggests differential physiological and life-history costs between the sexes. Overall, the findings here challenge previous assumptions about the lifespan and ageing biology of M. molossus, demonstrate that telomere maintenance is not limited to temperate bats and reinforce the value of long-term field studies for understanding ageing processes in the wild.