Behaviorial Endocrinology Research at Brookfield Zoo

Setting the Standards

As greater numbers of species are pushed to the brink of extinction, the Chicago Zoological Society continues to find innovative ways to protect threatened animals. The Behavioral Endocrinology Program was started in 2001 to take advantage of an exciting area of conservation science that helps improve the well-being and reproductive success of threatened species, both in zoos and in the wild.

Behavioral endocrinology combines the study of behavior and the study of hormones, enabling scientists to interpret changes in behavior based on changes in hormone levels. Because hormone levels now can be determined from samples obtained non-invasively (through fecal, urine and saliva samples), it is possible to regularly gather data without the risks that come with restraining animals or collecting blood samples.

A Leader In the Field

Our Behavioral Endocrinology Program positions CZS on the leading edge of scientific innovation. The Endocrine Lab is one of only a handful of labs worldwide focusing on threatened species specifically to address conservation issues. Ours is also the only lab at a major zoo to focus on the behavioral endocrinology of stress, which has earned us international recognition in the emerging field of zoo animal welfare.

The program has achieved groundbreaking successes in the areas of animal well-being and breeding for species as diverse as clouded leopards, Canada lynx, and callimico. We are currently monitoring hormone levels for dozens of species, located at Brookfield Zoo and at other accredited zoos. In many cases this is the first detailed physiological information ever gathered for a species.

Among its successes, the CZS’s Behavioral Endocrinology Program has:

Conducted multi-zoo research into the effects of environmental factors on the stress-hormone levels of clouded leopards, resulting in important stress-reducing enhancements in habitats.

Established pregnancy due dates for animals including aardvarks, black rhinos, giraffes, okapi, and red river hogs, helping keepers provide appropriate resources and support to expectant mothers and increasing healthy pregnancies and births.

Documented the seasonal reproductive cycle of the Southern hairy-nosed wombat, providing keepers with information they can use to schedule successful breeding introductions.