A zoo scientist analyzes hormone samples

Timing Animal Reproductive Cycles

Purpose

Endocrinologists can gain insight into animal reproductive cycles by measuring and monitoring testosterone, estrogen, and progesterone—the same hormones that guide reproduction in humans.

About

Every species has its own unique reproductive cycle, dependent on biology and environment. Some animals are seasonal breeders; others can mate year-round. Some species require specific foods, light cycles, or behavioral prompts to mate, and estrous time, gestational period, and duration between births can all vary.

Zoos are very careful to make the right matches to ensure the long-term health of the populations in their care. Endocrinologists can gain insight into animal reproductive cycles by measuring and monitoring testosterone, estrogen, and progesterone—the same hormones that guide reproduction in humans. This can provide valuable insight for ensuring baseline health and choosing the right time to introduce potential partners.

Most reproductive hormone measurements, both at the zoo and in the wild, come from non-invasive fecal samples, allowing scientists to gather valuable information to improve conservation and care without bothering the animals.

Staff

Rachel Santymire, Ph.D.
Director
Davee Center for Epidemiology and Endocrinology
Michelle L. Rafacz, Ph.D.
Adjunct Scientist
Davee Center for Epidemiology and Endocrinology

Contributors

Katie Fowler, M.S.