Results of the third reproductive assessment survey of north American Asian (Elephas maximus) and African (Loxodonta africana) female elephants
Publication Type: |
Journal Article |
Year of Publication: |
2011 |
Authors: |
T. L. Dow,, I. Holásková, J. L. Brown |
Publication/Journal: |
Zoo Biology |
Publisher: |
A Wiley Company, Inc., Wiley Subscription Services |
Keywords: |
acyclicity, hormones, ovarian cyclicity, progestagens, reproduction, ultrasound |
ISBN: |
1098-2361 |
Abstract:
A written survey assessed reproductive status of female Asian and African elephants in AZA/SSP facilities in 2008, and data were compared to surveys conducted in 2002 and 2005. Results showed that ovarian acyclicity rates across the surveys remained unchanged for Asian (13.3, 10.9 and 11.1%) and African (22.1, 31.2 and 30.5%) elephants, respectively (P>0.05), but were higher overall for African compared to Asian elephants (P<0.05). In 2008, the percentages of Asian and African elephants with irregular cycles (14.3 and 15.8%) and irregular + no cycles (25.4 and 46.4%) was similar to 2005 (7.6 and 11.8%; 18.5 and 43.0%), but were increased compared to 2002 (2.6 and 5.2%; 16.0 and 27.3%), respectively (P<0.05). For both species, ovarian acyclicity increased with age (P<0.05). Reproductive tract pathologies did not account for the majority of acyclicity, although rates were higher in noncycling females (P<0.05). Bull presence was associated with increased cyclicity rates (P<0.05) for Asian (92.5 vs. 58.3%) and African (64.9 vs. 57.8%) elephants compared to females at facilities with no male, respectively. Cyclicity rates were higher for Asian (86.8 vs. 65.2%) and African (67.9 vs. 56.7%) elephants managed in free compared to protected contact programs (P<0.05), respectively. Geographical facility location had no effect on cyclicity (P>0.05). In summary, incidence of ovarian cycle problems continues to predominantly affect African elephants. Although percentages of acyclicity did not increase between 2005 and 2008, 42.2% Asian and 30.2% African females were no longer being hormonally monitored; thus, reproductive cycle abnormalities could be worse than current data suggest. Zoo Biol 30:699–711, 2011. © 2011 Wiley Periodicals, Inc.