Age at first reproduction and senescence in Eastern chipmunks (Tamia striatus)

Senescence is the degradation of biological functions with increasing age. Its existence and relationship with life-history strategies remains poorly studied in short-lived wild vertebrate species. We investigated the relationships between age at first reproduction (AFR), reproductive senescence and longevity in an eastern chipmunk (Tamias striatus) population, where the first opportunity to breed is conditioned by pulses of seed production by trees (i.e., masts). We used 11 years of data from a longitudinal study, in which females breed for the first time at seven, 15, or 22 months of age and males at seven or 15 months of age. We first assessed the effect of age on three traits associated with breeding performance, namely the number of offspring produced, and the probability of weaning or siring a litter. We then tested whether an earlier AFR accelerated reproductive senescence and reduced survival of both males and females. We found sex-specific relationships between AFR and senescen..., These are data from a long term study on a population of eastern chipmunks in southern Quebec. We have followed individuals over their lifespan, to measure age at first reproduction, reproductive status, the probability of reproducing, number of offspring produced. We used Generalized linear mixed models on different reproductive traits in females and males, and a quadratic function of age, to test whether we could detect senescence patterns and whether age at first reproduction was linked to senescence., , # Age at first reproduction and senescence in Eastern chipmunks (Tamia striatus)

[https://doi.org/10.5061/dryad.pg4f4qrwr](https://doi.org/10.5061/dryad.pg4f4qrwr)

The data set represent 487 observation of reproduction for individual eastern chipmunks, captured between 2004 and 2018, on four study sites in southern Quebec, Canada.

## Description of the data and file structure

ID = individual ID
Age\_class = the age of the individual at first capture (J = juvenile ; A = adult)
site = name of the study grid
First\_capture = the date of first capture
Year\_birth = the year of birth
Cohort\_birth = one of the two types of birth cohort (chipmunks breed in the srping or in the summer)
cohort\_sexual\_maturity = one of the three category representing the age at which the animal first bred
AFR = age at first reproduction (in month)
Last-capture = the last capture of the animal (use to calculate lifespan)
lifespan = in month
weaned\_juv = whether the animal weaned juveniles during this repro...