Hormonal and behavioral correlates of estrus in captive giant pandas
Publication Type: |
Journal Article |
Year of Publication: |
2002 |
Authors: |
Laura McGeehan, Xuebing Li, Lori Jackintell, Shiqiang Huang, Aiping Wang, Nancy M. Czekala |
Publication/Journal: |
Zoo Biology |
Publisher: |
A Wiley Company, Inc., Wiley Subscription Services |
Keywords: |
ailuropoda melanoleuca, behavior, estrogens, estrus, progestins |
ISBN: |
1098-2361 |
Abstract:
Abstract 10.1002/zoo.10047.abs Variability in female estrus expression has been identified as a barrier to captive panda reproduction [Lindburg and Millard, 1995]. In China, researchers have reported that 80% of female giant pandas in captivity exhibit “weak estrus,” or “the absence of overt estrous behavior” [Shuling et al., 1997]. Previous research on the reproductive endocrinology and behavior of female giant pandas has been limited to one to three animals, limiting understanding of the causal factors related to variable estrous expression in captive animals. In 1997 a study was initiated to evaluate the reproductive biology and behavior of one of the largest captive populations of female giant pandas in China. A checksheet was developed to track the presence or absence of 13 behavioral and physiological indices of estrus in six captive females. Daily urine samples were analyzed for estrogens and progestins by enzyme-immunoassay to determine whether ovulation took place. The behavioral and physiological indicators were aligned to the estrogen peak to examine the relationship between behavior of and ovarian hormones. Analyses of urinary ovarian hormones indicated that all females ovulated during the study. The data revealed that behavioral and physiological indices differed in their temporal relationship to ovarian hormones. Scent-marking was present 6 days before the estrogen peak, but not afterwards. Bleat and chirp vocalizations were closely associated with the estrogen peak; however, receptive behaviors, such as lordosis and “tail up when touched,” were most closely associated with falling estrogens. Although all females displayed some type of estrous behavior during the study, individual females varied in the presence or absence of attractive, proceptive, and receptive behaviors. Despite the variation in the behavior of individual females, the hormonal data suggest that the variability in estrous expression in this population was not hormonally based. Zoo Biol 21:449–466, 2002. © 2002 Wiley-Liss, Inc.