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Why can female bats store sperm throughout hibernation?

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The image shows a group of Virginia big-eared bats sleeping upside down in a dark cavern. — Dormancy Virginia big-eared bats (*Corynorhinus townsendii virginianushibernating*) are true hibernators, entering a state close to death for much of the winter.

In many temperate-zone bat species, female bats store sperm in their reproductive tracts throughout hibernation to ensure that ovulation, fertilization, and implantation occur only after they emerge in the spring.12

This reproductive strategy is highly advantageous because it allows these events to take place when the female has access to an abundant food supply and a warm roost, which significantly enhances the survival chances of the young. By mating in the fall—when the bats are at their nutritional peak—and delaying fertilization until the spring, the species synchronizes the most energy-demanding phases of the reproductive cycle, such as gestation and lactation, with the most favorable environmental conditions.23