Changes in Survival with Age in Three Populations of a Long-lived Seabird, the Atlantic Puffin Fratercula arctica

Abstract

Actuarial senescence is the irreversible decline of survival with increasing age. This phenomenon varies widely between taxa and species along the slow-fast continuum. However, inter-populational senescence differences have been less investigated, especially in the avian order. Here, I compared senescence rate between three contrasting populations of the Atlantic puffin (Fratercula arctica), and between sex within colonies. To assess this, 31 years (1990- 2020) of capture-mark-recapture data from together 2101 individuals from Isle of May, Røst and Hornøya were used. Most of the individuals were marked as breeding adults with unknown absolute age, and time elapsed since first capture (TFC) was used as a proxy for age. Productivity data were used as proxy for environmental conditions experienced in the breeding season to understand variation in senescence rates between populations. I found differences in senescence between the colonies, but not between the sexes. Productivity had different effect on senescence between the colonies suggesting different cost of reproduction under variable environment in the breeding season. Finally, resighting rate decreased with age, potentially having a biological relevance if it reflects reduced breeding probability with age. The colony with the lowest reproduction over the study span also had the lowest rate of senescence, indicating that puffins might be able to buffer poor reproduction with lower rates of senescence.