Reproductive management is essential to meeting SSP genetic and demographic goals, enriching the lives of animals and supporting the long-term sustainability of captive populations. Temporarily preventing breeding in some individuals while promoting breeding in others is fundamental to successful population management. When genetically valuable animals fail to reproduce, the population loses genetic diversity; likewise, unplanned births in non-recommended pairs undermine careful population planning.
The AZA Reproductive Management Center (RMC), at the Saint Louis Zoo, previously known as the Wildlife Contraception Center, has historically advised the AZA community on the efficacy, safety, and reversibility of contraceptive products. The role of the RMC has expanded to include enhancing reproduction of recommended individuals. In particular, the RMC focuses on identifying and correcting causes of reproductive failure, such as infertility and pair incompatibility, and promotes Lifetime Reproductive Planning, that is, breeding females early and regularly to establish and maintain fertility. The RMC and its Advisory Board work closely with the Population Management Center, the Reproductive Health Surveillance Program, and coordinate efforts among relevant AZA Scientific Advisory Groups and Committees to address population-level threats to sustainability.
Four Main Areas of RMC
The RMC's Contraception Program maintains a Contraception Database containing over 30,000 records that are analyzed to continually update recommendations on efficacy and reversibility. The Reproductive Health Surveillance Program (RHSP), RMC's partner, studies the safety of contraceptives through comprehensive pathology examinations and analyses of reproductive tracts submitted by zoos and aquariums. The RMC works with commercial partners to bring new contraceptive methods to the AZA community, often at reduced cost. Ongoing communication between the RMC and members of the AZA community is critical to research efforts as well as overall program operation.
Successful reproduction in recommended pairs is critical to population management. Yet, fewer than 25% of breeding recommendations are fulfilled across AZA SSPs (Faust et al., 2011). While some failures can be attributed to logistics, more research is needed to identify the nuanced biological and social causes of reproductive failure. Emerging topics of study related to Reproductive Enhancement include identifying causes of female infertility and pair incompatibility, with the goal of improving reproductive success in affected individuals. Working with the AZA Population Management Center, and AZA Scientific Advisory Groups (SAGs) and Committees, the RMC promotes a holistic approach to evaluating reproductive failure, one that examines all possible elements (e.g., nutrition, behavior) rather than focusing on physiology alone.
Lifetime Reproductive Planning (LRP) considers each female's reproductive lifetime and examines breeding intervals needed to establish and maintain fertility for the species. LRP is based on analysis of historic breeding records, identifying factors (e.g., ages and experience of the male and female, inter-birth interval, rearing type, contraceptive history) that are associated with reproductive success. Those factors are then used to generate a statistical model that evaluates the impacts of various breeding scenarios on population demography and genetics for the species.
Achieving sustainability of AZA populations requires the coordinated efforts of members who are committed to AZA's mission and who represent diverse expertise. As part of its expansion, the RMC will integrate and work closely with the relevant AZA SAGs (Avian, Behavior, Biomaterials and Banking, Institutional Data Management, Molecular Data for Population Mangement, Nutrition, Reproduction and Endocrinology, Small Population Management Group, Veterinary) and Committees (Animal Health, Animal Welfare, Research and Technology, Wildlife Conservation and Management) to address population-level threats to sustainability. Each group has an essential role to play and collaboration among the groups can have a synergistic effect that could not be achieved by each group working alone.
Reproductive Health Surveillance Program
The partnership between the Reproductive Management Center (RMC) and the Reproductive Health Surveillance Program (RHSP) is central to the studies needed to support the reproductive health and fertility of zoo and wildlife species. Tissues submitted by participating institutions are analyzed and archived in a pathology database available for collaborative projects that benefit AZA Programs (TAGs, SSPs, etc). This archive allows us to detect disease patterns associated with various methods of reproductive management, including separation as well as contraception, and identify best practices. Note that these studies include tissues from both females and males, as well as prepubertal and post-reproductive animals. Analyses ensure that any side effects possibly related to contraceptive use or to separation are detected, and that recommendations are appropriately modified. Key to these studies, however, is the availability of reproductive tracts from uncontracepted animals, that is, "controls" for comparison to better understand the level of pathology that might be expected in an unmanipulated population. The RHSP is essential to the RMC's research on the relationship of reproductive health and infertility, by providing, for example, histological analysis of endometrial biopsies to diagnose uterine abnormalities. The quality of the data generated depends on the contents of the archive; the participation of your institution is critical to understanding this part of the "sustainability puzzle" in zoo populations.