Reproduction partially compensates for human‐caused mortality in a cooperative breeder

Abstract Reproductive output can vary widely among mammalian species. There are many drivers that affect reproductive output including evolutionary, environmental, population, social, and individual traits. Although several factors, including human‐caused mortality, can affect reproductive output, we generally have a poor understanding of how such factors interact to affect reproduction, particularly in cooperative breeders. Gray wolves (Canis lupus) in Idaho, USA, are exposed to annual hunting and trapping. Thus, they are an ideal species to answer questions about how turnover within groups affects reproduction in cooperative breeders. I hypothesized that the reproductive output of wolves would be affected by individual, social, and environmental factors. Contrary to my prediction, mid‐summer litter size was positively associated with wolf harvest density, suggesting a compensatory response to harvest in cooperatively breeding gray wolves. Such compensation is only partial, however, and does not fully account for all the individuals lost from harvest. At the very highest harvest densities observed, mean litter size increased nearly 28%. In contrast, mid‐summer litter size was negatively associated with multiple breeding in groups, suggesting resource limitation and competition within groups. I show that characteristics associated with harvest and breeding strategies predict variations in litter size in a cooperative breeder.