Walker CCF, Schlegel ML. 2013. Case Study: relationship between weight gain and offspring sex in African bush elephants (Loxodonta Africana african) at the San Diego Zoo Safari Park. In Ward A, Coslik A, Mahan K, Treiber K, Reppert A, Maslanka M, Eds. Proceedings of the Tenth Conference on Zoo and Wildlife Nutrition, AZA Nutrition Advisory Group, Salt Lake City, UT.
Facing a male biased offspring sex ratio (7:4) in the African bush elephant (Loxodonta africana africana) population at the San Diego Zoo Safari Park (SP), the overall weight and weight gain of the breeding females was analyzed and the weight gain prior to calf conception was determined. The breeding females arrived at the SP heavier than similarly aged Zambian female elephants used as a comparison. The females remained heavier and gained more weight than the Zambian females over the 10 years at the SP. Despite the male biased offspring, the sex ratio in this small population is not different than 50:50 (X2 = 0.818; df = 1; P = 0.40). There was no difference in the weight gain of breeding females 6 mo or 1 year prior to conception on the resulting sex of calf. Further monitoring of weight gain trends and offspring sex ratio needs to be done to determine if weight gain prior to conception influences calf sex. Additionally, monitoring body weight and body condition of the breeding female elephants at the San Diego Zoo Safari Park ensures a healthy reproductive live and preventing obesity.28_Walker.pdf     137 KB