Zoo Biology最新文献

Retention of genetic diversity in successive generations is key to successful ex situ programs and will become increasingly important to restore wild populations of threatened animals. When animal genealogy is partly unknown or gaps exist in studbook records, the application of molecular resources facilitates informed breeding. Here, we apply molecular resources to an ex situ breeding population of toucans (Ramphastidae), a bird family zoos commonly maintain. Toucans face population declines from illegal poaching and habitat degradation. We developed novel microsatellite markers using blood samples from 15 Keel-billed Toucans (Ramphastos sulfuratus Lesson 1830). Parentage of two individuals was known a priori, but possible sibship among 13 putative founders-including the parents-was unknown. We compared available avian heterologous and novel microsatellite markers to recover known relationships and reconstruct sibship. Eight of 61 heterologous markers amplified consistently and were polymorphic, but less so than the 18 novel markers. Known sibship (and three sibling pairs whose relatedness was unknown a priori) and paternity-though not maternity except in one case-were well-recovered using both likelihood and pairwise relatedness methods, when incorporating novel but not heterologous markers. Zoo researchers seeking microsatellite primer sets for their breeding toucan populations will likely benefit from our heterologous markers, which can be leveraged both to assess relatedness and select breeding pairs. We recommend that zoo biologists rely on species-specific primers and not optimize heterologous primers for toucan species without molecular resources. We conclude with a brief discussion of modern genotyping methods of interest to zoo researchers.

Zoo animal husbandry is a skill that should be developing constantly. In theory, this should lead to an improvement of zoo animal survivorship over time. Additionally, it has been suggested that species that are at a comparatively higher risk of extinction in their natural habitats (in situ) might also be more difficult to keep under zoo conditions (ex situ). Here, we assessed these questions for three zoo-managed rhinoceros species with different extinction risk status allocated by the IUCN: the "critically endangered" black rhino (Diceros bicornis), the "vulnerable" greater one-horned (GOH) rhino (Rhinoceros unicornis), and the "near threatened" white rhino (Ceratotherium simum). Comparing zoo animals ≥1 year of age, the black rhino had the lowest and the white rhino the highest survivorship, in congruence with their extinction risk status. Historically, the survivorship of both black and white rhino in zoos improved significantly over time, whereas that of GOH rhino stagnated. Juvenile mortality was generally low and decreased even further in black and white rhinos over time. Together with the development of population pyramids, this shows increasing competence of the global zoo community to sustain all three species. Compared to the continuously expanding zoo population of GOH and white rhinos, the zoo-managed black rhino population has stagnated in numbers in recent years. Zoos do not only contribute to conservation by propagating ex situ populations, but also by increasing species-specific husbandry skills. We recommend detailed research to understand specific factors responsible for the stagnation but also the general improvement of survivorship of zoo-managed rhinos.

Captive animals typically develop anticipatory behaviors, actions of increased frequency done in anticipation of an event such as feeding. Anticipatory behaviors can be an indicator of an animal's welfare. However, for rehabilitating animals that are expected to be reintroduced into the wild, these behaviors need to be extinguished to ensure successful release. Scheduled activities such as feeding occur daily and vocalizations could potentially be used to identify anticipatory behavior. Here, we tested the hypothesis that manatee calves modify their vocal production rate as a form of anticipatory behavior. Vocalizations of two Antillean manatee (Trichechus manatus manatus) calves were recorded for 10 min before, during, and after feeding sessions at Wildtracks, a manatee rehabilitation center in Belize. The number of calls were counted across recording sessions and three acoustic parameters were measured from calls including duration, frequency modulation, and center frequency. A repeated measures ANOVA comparing the number of calls across sessions indicated manatees produced significantly more calls before feeding sessions than during and after sessions. In addition, manatees increased the duration and lowered the frequency of calls before feeding sessions. This information can give further insight on ways to improve rehabilitation protocols and manage human interactions to increase the overall survival rate of rehabilitated manatees when released back into the wild.

This study provides ultrasonographic fetal growth charts for the Eastern black-and-white colobus monkey (Colobus guereza). Throughout three consecutive gestations (-162 to -2 days to parturition) in a single dam, we opportunistically obtained ultrasonographic measurements for the following parameters: biparietal diameter, head circumference, humerus length, femur length, tibia length, radius length, thoracic width, kidney length, and crown-rump length. Biparietal diameter was the most consistently measured parameter. First detection of fetuses occurred between 96 and 162 days before parturition. This report demonstrates that voluntary transabdominal ultrasound can be well-tolerated in the colobus monkey using operant conditioning. These findings may be useful to assess fetal development and predict parturition dates in the absence of a known conception date in this species.

Although cryobanking represents a powerful conservation tool, a lack of standardized information on the species represented in global cryobanks, and inconsistent prioritization of species for future sampling, hinder the conservation potential of cryobanking, resulting in missed conservation opportunities. We analyze the representation of amphibian, bird, mammal, and reptile species within the San Diego Zoo Wildlife Alliance Frozen Zoo® living cell collection (as of April 2019) and implement a qualitative framework for the prioritization of species for future sampling. We use global conservation assessment schemes (including the International Union for Conservation of Nature (IUCN) Red List of Threatened Species™, the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), the Alliance for Zero Extinction, the EDGE of Existence, and Climate Change Vulnerability), and opportunities for sample acquisition from the global zoo and aquarium community, to identify priority species for cryobanking. We show that 965 species, including 5% of all IUCN Red List "Threatened" amphibians, birds, mammals, and reptiles, were represented in the collection and that sampling from within existing zoo and aquarium collections could increase representation to 16.6% (by sampling an additional 707 "Threatened" species). High-priority species for future cryobanking efforts include the whooping crane (Grus americana), crested ibis (Nipponia nippon), and Siberian crane (Leucogeranus leucogeranus). Each of these species are listed under every conservation assessment scheme and have ex situ populations available for sampling. We also provide species prioritizations based on subsets of these assessment schemes together with sampling opportunities from the global zoo and aquarium community. We highlight the difficulties in obtaining in situ samples, and encourage the formation of a global cryobanking database together with the establishment of new cryobanks in biodiversity-rich regions.

It is important that the environment provided in the zoo is relevant to the species being housed and its suitability be easily assessed by personnel. As shared space and resources can overlap in a zoo's enclosure a tool is required to measure the effects of such overlap between individual animals in a shared enclosure. This paper outlines the Pianka Index (PI), a tool used in ecology to quantify niche overlap, that has value in quantifying the amount of time that animals spend in shared enclosure zones. One limitation to this method, however, is that the established method of determining the PI requires division of the enclosure into equally sized zones, something that is not always relevant to a zoo enclosure. To combat this, we created a modified index, entitled the Zone Overlap Index (ZOI). This modified index is the exact mathematical equivalent of the original index when zone sizes are equal. When zone sizes are unequal, the ZOI generates higher values when animals share smaller, as opposed to larger, zones. This is because animals are more likely to share larger enclosure zones simply by chance, and shared use of smaller zones brings individuals into closer proximity with the potential for competition. To illustrate the application of the ZOI, a series of hypothetical situations were generated to reflect real-world scenarios, demonstrating how this index could be used to better understand zone occupancy overlap in the zoo.

Zoo management techniques for captive birds, such as flight restraint and enclosure type, may affect behavioral performance and are consequently worthy of investigation. Flamingos are amongst the most popular of zoo-housed birds and, as such, research into their captive management and associated behavioral responses are widely applicable to many thousands of individuals. As a highly social species, understanding social bonds and behavior of the individual bird and the flock overall can help inform decisions that support husbandry and population management. In this project, 41 greater flamingos at Bristol Zoo Gardens were observed for 49 days across spring and summer 2013 to assess the following: (i) social associations within the flock, (ii) overall activity patterns, and (iii) distribution of time within specific enclosure zones for both full-winged and flight-restrained birds living in the same enclosure. Results showed that pinioning interacted with age in regard to flamingo time-activity patterns, but wing condition did not significantly influence association patterns, performance of social interactions, or performance of breeding behavior. Social network analysis revealed that associations were nonrandom and flamingos, of either wing condition, displayed different roles within the network. Birds of similar age formed the strongest bonds. Enclosure usage was not even, suggesting that the flamingos favored specific areas of the enclosure during the observation period. This study showed that wing condition does not affect flamingo behavior, social bonds, or space use, and that age and sex have more of an overall influence on what flamingos do, and with whom they chose to do it. Further research should extend this study into other, larger captive flocks to further refine behavioral measures of welfare for these popular zoo birds.

For some critically endangered species, conservation breeding is a vital steppingstone toward re-establishing wild populations. The 'Alalā (Hawaiian crow, Corvus hawaiiensis), currently extinct in the wild, exists today only in a conservation breeding program, which, for many years, utilized successful hands-on husbandry approaches such as separating and resocializing pairs, providing partially manmade nests, artificially incubating eggs, and puppet rearing nestlings. Yet, a top priority of any conservation breeding program is to retain natural behaviors essential to postrelease survival and reproduction, to achieve successful reintroduction and restoration to the wild. We describe how we are adapting 'Alalā husbandry techniques to strengthen pair bonds through full-time socialization, enable pairs to build robust nests, encourage females to incubate eggs to hatch, and provide pairs and their offspring with vital parental rearing experiences. We discuss the use of standardized, data-driven methods to objectively track our progress towards successful parental breeding and to select release candidates based on their likelihood to survive and breed in the wild. The information shared in this report can be applied to other conservation breeding programs, particularly those implementing or transitioning to husbandry techniques geared towards preparing species to thrive in the wild.

The effect of visitor presence on animal behavior needs to be evaluated to ensure the welfare and improve the husbandry of the individuals in zoos. This study aims to assess the effect of visitor presence on the behavior and welfare of pairs of Amur tiger, snow leopard, and Eurasian lynx at Parco Natura Viva, Italy. The study was made of two periods: the baseline, in which the zoo was closed, and the visitor presence period, in which the zoo was opened. Per period and per subject 12 30-min observations were done. Continuous focal animal sampling method was used to collect behavior duration of the big cats. The main results of the study highlighted that, when visitors were present, all felids except for the female lynx were significantly more inactive than in the baseline. Moreover, despite interindividual and inter-species variability in the significance level of findings, natural behaviors such as attentive behavior, exploration/marking, locomotion, and positive social interactions were performed more in the baseline than in the visitor presence period. Finally, when visitors were present, as the studied subjects experienced daily longer exposure to visitors, inactivity increased whereas individual species-typical behaviors (e.g., locomotion) and positive social interactions decreased. Thus, visitors seem to partially alter the behavioral time-budgets of the study big cats, increasing inactivity and decreasing the performance of species-specific behavior, at least in some individuals.

Animal habitats are changing around the world in many ways, presenting challenges to the survival of species. Zoo animal populations are also challenged by small population sizes and limited genetic diversity. Some ex situ populations are managed as subpopulations based on presumed subspecies or geographic locality and related concerns over genetic purity or taxonomic integrity. However, these decisions can accelerate the loss of genetic diversity and increase the likelihood of population extinction. Here I challenge the wisdom of subpopulation management, pointing out significant concerns in the literature with delineation of species, subspecies, and evolutionarily significant units. I also review literature demonstrating the value of gene flow for preserving adaptive potential, the often-misunderstood role of hybridization in evolution, and the likely overstated concerns about outbreeding depression, and preservation of local adaptations. I argue that the most effective way to manage animal populations for the long term be they in human care, in the wild, or if a captive population is being managed for reintroduction, is to manage for maximum genetic diversity rather than managing subpopulations focusing on taxonomic integrity, genetic purity, or geographic locale because selection in the future, rather than the past, will determine what genotypes and phenotypes are the most fit. Several case studies are presented to challenge the wisdom of subpopulation management and stimulate thinking about the preservation of genomes rather than species, subspecies, or lineages because those units evolved in habitats that are likely very different from those habitats today and in the future.