Consequences of the environment: timing of litter parturition and offspring survival in the social rodent Octodon degus

Variation in the timing of offspring parturition determines the environmental factors they experience during early development and their likelihood for survival. I used an 11-year dataset on a natural, free-living population of degus (Octodon degus), a social rodent endemic to Chile, to test predictions that ecological, social, and maternal conditions during the breeding season are associated with the timing of litter parturition and intragroup litter synchrony and that early-life conditions and the time at which pups are born influence their survival. Measures of females’ food access during breeding predicted their parturition day. Furthermore, differences in food abundance and phenotypical masculinization between female groupmates predicted differences in their parturition day. Females that experienced more food during breeding gave birth earlier in the year and female groupmates with similar masculinization and food shared greater differences in their parturition day. No effects of early-life conditions nor parturition day on offspring survival were identified