Spatio-temporal variation in lifelong telomere dynamics in a long-term ecological study

Area of Science:

• Ecology
• Evolutionary Biology
• Gerontology

Background:

• Individual variation in environmental responses is key to life-history evolution and population dynamics.
• Telomere shortening, linked to oxidative stress, correlates with reduced survival and lifespan.
• Telomere dynamics can quantify individual costs from social and ecological factors.

Purpose of the Study:

• To analyze spatio-temporal variation in lifelong telomere dynamics in Seychelles warblers.
• To investigate how telomere dynamics change with age, cohorts, and environmental factors.
• To understand the relationship between telomere length and survival costs in a natural population.

Main Methods:

• Longitudinal study of Seychelles warblers (Acrocephalus sechellensis) combining life history, ecological, and telomere length data.
• Analysis of 1,808 samples from 22 cohorts (1993-2014) to track telomere dynamics over individual lifespans.
• Statistical analysis of repeated measurements to differentiate biological changes from measurement error.

Main Results:

• Telomere length decreases with age, particularly early in life, but increases were observed in some individuals, unlikely due to measurement error.
• Telomere length varied significantly across cohorts and was positively associated with insect abundance, a key food resource.
• Sex-specific relationships between telomere length and tarsus length suggested differential growth costs.

Conclusions:

• Telomere dynamics in Seychelles warblers are complex, varying across individual lifespans, space, and time.
• Environmental factors, such as resource availability, significantly impact telomere dynamics.
• Further research integrating genetic and long-term ecological data is needed to fully explain individual variation in telomere dynamics.