Effects of combination birth control on estrous behavior in captive western lowland gorillas, Gorilla gorilla gorilla
Article first published online: 14 JUN 2011
© 2011 Wiley Periodicals, Inc.
Volume 31, Issue 3, pages 350–361, May/June 2012
How to Cite
Sarfaty, A., Margulis, S. W. and Atsalis, S. (2012), Effects of combination birth control on estrous behavior in captive western lowland gorillas, Gorilla gorilla gorilla. Zoo Biol., 31: 350–361. doi: 10.1002/zoo.20401
- Issue published online: 13 JUN 2012
- Article first published online: 14 JUN 2011
- Manuscript Accepted: 9 MAY 2011
- Manuscript Revised: 28 APR 2011
- Manuscript Received: 6 FEB 2011
- lowland gorilla;
- combination birth control;
- estrous behavior
Combination birth control pills (CBC) are one of the most common birth control methods used for western lowland gorillas (Gorilla gorilla gorilla) housed in zoos. Since zoos are interested in maintaining as many natural behaviors as possible, it is important to know how contraception may affect social and sexual interactions among group members. Although some data are available regarding the influence of the pill on sexual behavior in human females, no data are available on its effects on gorilla estrous behavior. We examined temporal trends of estrous, aggressive, affiliative, and activity budget data in four females on CBC at the Lincoln Park Zoo in Chicago, IL. Behavioral data were collected using point sampling, all-occurrence records, and one-zero sampling. Estrous behavior occurred in less than 1% of observations. Using all-occurrence and one-zero sampling, estrous behavior occurred more frequently in week one of the cycle than any other week. The focal females exhibited affiliative, aggressive, and activity budget data evenly across their cycles. There were also no temporal trends in proximity to the silverback. Females varied by the types of estrous behavior they exhibited. We give a hormonal explanation for the prevalence of estrous behaviors in week one, and recommendations for effective behavioral sampling of gorilla estrous behavior. Zoo Biol 31:350–361, 2012. © 2011 Wiley Periodicals, Inc.