Grizzly Bear Vagina
This photo shows a female grizzly bear’s vagina during mating season. Her genitals are swollen and more visible than other times of the year. This suggests that male bears may use their sense of sight (in addition to smell) to determine if a female bear is in estrus (ovulating).
Grizzly bear females will ovulate once a year usually in May and June. If her eggs are successfully fertilized, the baby bears will be born in the middle of winter while she is in her den. Her eggs may be fertilized by more than one grizzly male, meaning that grizzly bear siblings may have different fathers. Occasionally you will wonder about this when you spot cubs that are the same age but drastically different sizes.