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The South China tiger Panthera tigris amoyensis is the rarest of thefive living tiger subspecies, the most critically threatened and theclosest to extinction. No wild South China tigers have been seen by officials for 25 years and one was last brought into captivity 27 years ago. The 19 reserves listed by the Chinese Ministry of Forestry within the presumed range of the tiger are spatially fragmented and most are too small to support viable tiger populations. Over the last 40years wild populations have declined from thousands to a scattered few. Despite its plight and occasional anecdotal reports of sightings by local people, no intensive field study has been conducted on this tiger subspecies and its habitat, The captive population of about 50 tigers, derived from six wild-caught founders, is genetically impoverished with low reproductive output. Given the size and fragmentation of potential tiger habitat, saving what remains of the captive population may be the only option left to prevent extinction of this tiger subspecies, and even this option is becoming increasingly less probable. This precarious dilemma demands that conservation priorities be re-evaluated and action taken immediately to decide if recovery of thewild population will be possible. [ABSTRACT FROM AUTHOR]

The golden lion tamarin (GLT) is an Endangered primate endemic to Brazil's lowland Atlantic Forest. After centuries of deforestation and capture for the pet trade, only a few hundred individuals survived, all in isolated forest fragments 85 km from Rio de Janeiro city. Intensive conservation actions, including reintroduction of zoo-born tamarins, increased numbers to about 3700 in 2014. The most severe yellow fever epidemic/epizootic in Brazil in 80 years reduced two of the largest GLT populations by over 90%. Herein we report the results of a 2023 survey of GLTs designed to examine the dynamics of population recovery following yellow fever. Results indicate that populations hard hit by yellow fever are recovering due in part to immigration from adjacent forest fragments. No local extirpations were observed. About 4800 GLTs live in the survey area. This represents a 31% increase since the baseline survey completed in 2014. Two factors explain most of the increase: four large areas that had no GLTs or very low-density populations in 2014 are now at moderate density (three areas) or low density (one area), explaining 71% of overall increase since 2014. Increase in forest area within our survey area may explain up to 16% of the increase in GLT numbers since 2014. Results of computer simulations suggest that strengthening forest connectivity will facilitate metapopulation resilience in the face of mortality factors such as yellow fever., (© 2024 Wiley Periodicals LLC.)

Genome resource banks (GRBs) have the potential to preserve the genetic diversity of a species over time, yet they are rarely utilized as effective components of conservation breeding programs. Advances have been made in reproductive biology, collection and storage techniques, and use of stored gametes for achieving successful reproduction, but there are few guidelines for integrating GRBs into established breeding programs. Here we present basic guidelines, focusing on strategies for the collection, maintenance, and use of semen GRBs for protecting genetic diversity. These guidelines should be applied in the context of the specific purposes and roles of a breeding program's GRB, which will differ among species depending on vulnerability to loss and the status of rescue and conservation efforts. We recommend establishing up to three types of collections: (1) a National Reserve to preserve a species' genetic diversity, to be used only as a last resort; (2) a Savings Account to be used periodically to invigorate a genetically depauperate population; and (3) a Checking Account to be used as a regular part of the breeding program. We present methods for identifying donors to maximize genetic diversity in a GRB, as well as strategies for maintaining and optimally using GRBs., (© 2022 The Authors. Zoo Biology published by Wiley Periodicals LLC.)

Maintaining a living plant collection is the most common method of ex situ conservation for plant species that cannot be seed banked (i.e., exceptional species). Viability of living collections, and their value for future conservation efforts, can be limited without coordinated efforts to track and manage individuals across institutions. Using a pedigree-focused approach, the zoological community has established an inter-institutional infrastructure to support long-term viability of captive animal populations. We assessed the ability of this coordinated metacollection infrastructure to support the conservation of 4 plant species curated in living collections at multiple botanic gardens around the world. Limitations in current practices include the inability to compile, share, and analyze plant collections data at the individual level, as well as difficulty in tracking original provenance of ex situ material. The coordinated metacollection framework used by zoos can be adopted by the botanical community to improve conservation outcomes by minimizing the loss of genetic diversity in collections. We suggest actions to improve ex situ conservation of exceptional plant species, including developing a central database to aggregate data and track unique individuals of priority threatened species among institutions and adapting a pedigree-based population management tool that incorporates life-history aspects unique to plants. If approached collaboratively across regional, national, and global scales, these actions could transform ex situ conservation of threatened plant species., (© 2020 The Authors. Conservation Biology published by Wiley Periodicals LLC on behalf of Society for Conservation Biology.)

Many animal populations managed by the Association of Zoos and Aquariums' (AZA) Species Survival Plans® (SSPs) have low rates of reproductive success. It is critical that individuals recommended to breed are successful to achieve genetic and demographic goals set by the SSP. Identifying factors that impact reproductive success can inform managers on best practices and improve demographic predictions. A Reproductive Viability Analysis (RVA) utilizes data gathered from Breeding and Transfer Plans, studbooks, and SSP documents, and through modeling identifies factors associated with reproductive success in a given species. Here, we describe the RVA process, including different statistical models with the highest accuracy for predicting reproductive success in fennec foxes (Vulpes zerda) and Mexican wolves (Canis lupus baileyi). Results from the RVA provide knowledge that can be used to make evidence-based decisions about pairing and breeding strategies as well as improving reproductive success and population sustainability., (© 2019 Wiley Periodicals, Inc.)

Most threatened species do not yet have an integrated conservation plan to guide zoos and aquariums in species selection and conservation action. To address this issue, the Conservation Planning Specialist Group (CPSG), in collaboration with regional zoo and aquarium associations, has developed a new process-an Integrated Collection Assessment and Planning (ICAP) workshop. This brings in situ and ex situ communities together to apply the decision process of the IUCN SSC Guidelines on the Use of Ex Situ Management for Species Conservation to the task of regional or global collection planning. The first ICAP workshop was held in 2016 for 43 canids and hyaenids in collaboration with the relevant regional zoo and aquarium associations and IUCN Specialist Groups. The ICAP process provides a comprehensive assessment that will enhance species conservation by providing guidance to zoos and aquariums on conservation priorities for collection planning, conservation education messaging, in situ field support, and integration of in situ and ex situ efforts, as well as by promoting collaboration among regional zoo and aquarium associations, field-based conservationists, and IUCN SSC Specialist Groups., (© 2019 Wiley Periodicals, Inc.)

Understanding factors that influence reproduction and offspring survival in zoo populations is critical for management of threatened and endangered species. Examination of long-term data (1989-2011) compiled from the Association of Zoos and Aquarium's zoo-managed tiger breeding program provides the basis for a more thorough understanding of reproduction and scientifically based decisions for effective population management in this endangered felid. Biological and management-related factors that could influence tiger breeding success and cub survival were evaluated using logistic mixed models. Breeding success improved with female age until approximately age five, then declined thereafter. Experienced female breeders had greater breeding success than inexperienced females. Litter size was most predictive of cub survival, with average-sized litters (3-4 cubs) experiencing the highest proportional survival. Management-related factors, such as whether the breeding institution had a recent tiger litter and whether both animals were already located at the same institution, also influenced breeding success and cub survival. These results highlight the importance of institutional husbandry experience and the need to retain knowledge through staff turnovers to achieve optimal reproductive success. Using fecal estrogen data, frequency of ovarian cyclicity and mean cycle length did not differ by female age or parity; thus, lack of cyclicity and/or increased cycle duration are not likely explanations for declining breeding success with age. These results provide valuable reproductive information that should improve scientific management of zoo-based tiger populations., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Zoos and other ex situ wildlife institutions can play an important role in species conservation by maintaining populations for education and research, as sources for potential re-introduction or reinforcement, and as ambassadors for financial support of in situ conservation. However, many regional zoo associations are realizing that current captive populations are unsustainable, with many programs failing to meet demographic and genetic goals to ensure long-term viability. Constraints on population size due to limited space often mandate delayed and/or less frequent breeding, but for females of many species this can have profound effects on fertility. A retrospective analysis combined with published literature and reliable anecdotal reports reveals that, when females are housed in a non-breeding situation for extended periods of time, reproductive changes that negatively impact fertility have occurred in multiple species, including canids, elephants, white rhinoceros, Seba's bats, wildebeest, stingrays, and some felid species. Competing space needs and changing interest in taxa for exhibits over time compound the problem. Counter strategies to breed early and often have their own demographic and genetic consequences as well as logistical and political implications. Strategies to mitigate the sustainability crisis in these taxa might include a mixed strategy in which young, genetically valuable females are bred earlier and at more regular intervals to ensure reproductive success, in combination with the judicious use of available tools to manage the number of offspring produced, including contraception and culling. An understanding of the issues at stake is the first step towards developing management strategies for sustainable populations., (© 2013 Wiley Periodicals, Inc.)

Tigers (Panthera tigris) are disappearing rapidly from the wild, from over 100,000 in the 1900s to as few as 3000. Javan (P.t. sondaica), Bali (P.t. balica), and Caspian (P.t. virgata) subspecies are extinct, whereas the South China tiger (P.t. amoyensis) persists only in zoos. By contrast, captive tigers are flourishing, with 15,000-20,000 individuals worldwide, outnumbering their wild relatives five to seven times. We assessed subspecies genetic ancestry of 105 captive tigers from 14 countries and regions by using Bayesian analysis and diagnostic genetic markers defined by a prior analysis of 134 voucher tigers of significant genetic distinctiveness. We assigned 49 tigers to one of five subspecies (Bengal P.t. tigris, Sumatran P.t. sumatrae, Indochinese P.t. corbetti, Amur P.t. altaica, and Malayan P.t. jacksoni tigers) and determined 52 had admixed subspecies origins. The tested captive tigers retain appreciable genomic diversity unobserved in their wild counterparts, perhaps a consequence of large population size, century-long introduction of new founders, and managed-breeding strategies to retain genetic variability. Assessment of verified subspecies ancestry offers a powerful tool that, if applied to tigers of uncertain background, may considerably increase the number of purebred tigers suitable for conservation management.

The need for contraception in the successful management of captive wild animals is becoming increasingly apparent. Because concerns exist regarding the reversibility of the contraceptive implant melengestrol acetate (MGA), reproductive data for 94 female Amur (Panthera tigris altaica) and Sumatran tigers (Panthera tigris sumatrae) were analyzed using survival analyses to evaluate return to reproductive status after implant removal or assumed expiration. Females placed in potential breeding situations after MGA implants were surgically removed showed a 62% return to reproduction by 5.25 years, whereas females with implants that were assumed to have expired showed only a 30% return to reproduction by 6 years. Implanted females did not reproduce as successfully as non-implanted control females, which showed an 85% probability of reproducing after placement in a new breeding situation by 2.66 years. Parturition increased the probability of reproducing in non-implanted females, but not in implanted females. Litter size, stillbirths, and offspring survival were not significantly different between non-implanted, implant-removed and implant-expired female tigers. Ten female tigers reproduced both before and after implant placement, and the differences in litter size, stillbirths, and offspring survival were not significant, nor were they significantly different from non-implanted females. Prior parturition, age when implant was removed, and duration of implantation did not affect the probability of reproducing for females after implant removal. These results show substantial reversibility of MGA implants, leading to 62% successful reproduction after implant removal. The reasons for lower successful reproduction in animals previously treated with the contraceptive compared to non-implanted females are not known, but a greater delay in reversibility was seen when implants were left in place and only presumed expired. Zoo Biol 26:275-288, 2007. (c) 2007 Wiley-Liss, Inc.