Infanticide occurs in a diversity of taxa and may provide benefits to the perpetrator through nutritional gain, reduced competition, or increased fitness from mating opportunities through sexually selected infanticide (SSI). Infanticide, however, is rarely observed. We documented a probable infanticide event by a 23-year-old adult male polar bear (Ursus maritimus) on a 3-month-old cub in western Hudson Bay, Canada, during the spring of 2023. We subsequently documented a 21-year-old solitary female who was lactating and in breeding condition with swollen labia, suggesting polar bears return to estrous quickly in the absence of cubs. Using the literature, we examined the relationships among polar bear cub-of-the-year, adult male survival, and the ratio of male/female mortality. We suggest SSI as the plausible explanation for the infanticide event observed and discuss how indirect effects from climate change may affect the prevalence of infanticide as a mechanism regulating polar bear populations.
- Volume 35
- Issue 20
- Pages 1-11
- Publication Date 29 October 2024
- DOI 10.2192/ursus-d-23-00028
- File Size 784.66 KB
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