© Peggy Armer, Fresno Chaffee Zoo
Reproductive Physiology is an important factor that must be considered to ensure the highest standards of animal and population care, health, and welfare. Understanding the reproductive physiology of individual species allows animal care and population management specialists the opportunity to ensure high genetic diversity and augment the conservation of threatened and endangered species. The AZA Wildlife Contraception Center, Population Management Center, Reproduction Scientific Advisory Group, and Endocrinology Scientific Advisory Group play vital roles in the management of the animal populations cared for in AZA-accredited institutions. In a world where human-influenced factors are threatening or endangering increasing numbers of species, it is imperative that experts in the assisted reproduction field collaborate to develop, implement, and share new technologies to promote progressive conservation initiatives and strategies.
Hormone and Pregnancy Monitoring
Scientists working in the field of animal and/or human reproductive medicine and physiology have developed techniques to measure reproductive hormones in either urine or feces for many species (e.g. okapi, manatee, etc.). This ability is important for determining reproductive cycles, evaluating the fertility or infertility of individuals, diagnosing pregnancy, determining gestation lengths, and predicting parturition.
Cryopreservation of Gametes
The technology of cryopreserving gametes by storing them in liquid nitrogen has been well established with humans and several domesticated species, however this methodology is not as refined and often requires significant modification for applications with non-domesticated and threatened species (e.g. killer whales, tigers, etc.). The success rate of obtaining founder or under-represented male gametes, cryopreserving them and using artificial insemination techniques to generate young varies considerably from species to species, as well as from individual to individual. Advancement of these technologies is crucial for ensuring the long term sustainability of many species populations.
Artificial insemination techniques provide a straightforward opportunity for increasing genetic diversity among managed species. The ability to use semen collected from males residing in different AZA accredited institutions, or from new founders in the wild during routine health assessments, eliminates complications that may be associated with the transporting of animals into new habitats and social groups. Although artificial insemination techniques have been successfully implemented with anesthetized animals, many species have been behaviorally conditioned to voluntary participate in these same procedures. Dolphin males, for instance, are easily trained to provide semen samples with a simple hand cue while females are trained to remain stationary for the insemination procedure.
In Vitro Procedures
Precise handling and processing of mammalian oocytes can play a valuable role in producing embryos by in vitro fertilization that can then be implanted into receptive females. This methodology may be particularly valuable if utilized with a species that is endangered or threatened because the male often inflicts detrimental or lethal injuries to the female during normal mating behaviors (e.g. amur leopard).