Defying Expectations: Extended Lifespan and Age-Related Telomere Dynamics in the Tropical Bat Species, Molossus molossus.

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. Relative telomere length (rTL) showed a negative association with age, although this association was not retained in sensitivity analyses. Males consistently exhibited longer telomeres than females in both robust and age-matched analyses, while there was no evidence that age-related telomere dynamics differed between the sexes. Overall, these findings challenge previous assumptions about the lifespan and ageing biology of M. molossus. They reveal a difference between the sexes in mean telomere length and reinforce the value of long-term field studies for understanding ageing processes in the wild.