Telomere Length Is Determined by Intrinsic Factors and Is Shortened During Drought Years in Gallotia galloti

Abstract

Telomeres have emerged as important indicators of organismal longevity and population health; however, our understanding of their dynamics in ectotherms remains incomplete. Here, we investigated variables influencing relative telomere length (rTL) in the Western-Canaries Lizard (Gallotia galloti) across diverse environments over 10 years. Using mixed-effect model-averaging and hierarchical partitioning, we assessed the effects of intrinsic morphological (sex and body length) and extrinsic environmental (elevation, radiant sky temperature, wind speed and relative humidity) factors while controlling for temporal (year sampled) effects on rTL variation. In addition, we investigated temporal signals corresponding to extreme weather events over the sampling period. Intrinsic factors had the strongest influence, with males exhibiting shorter rTL than females, and females showing shorter rTL with increasing size. Temporal patterns revealed a negative correlation with dry years, indicating that even though environmental drivers may be secondary predictors compared to individual determinants, severe weather conditions may represent cumulative burdens. Multiple intrinsic and extrinsic variables, including climate, should be considered when investigating telomere dynamics in ectotherms.