Zoo Biology最新文献

It has been suggested repeatedly that zoo-kept giant anteaters (Myrmecophaga tridactyla) have higher body masses than their free-ranging conspecifics. Here, we assess this hypothesis by comparing body mass data of 184 female and 173 male individuals kept in zoos to published and unpublished data of free-ranging animals (n = 215). In zoos, the average adult body mass of all individuals was 45.9 ± 9.6 kg (range 19.2-72.6 kg), whereas body mass for free-ranging specimens was 33.0 ± 2.3 kg (21-45.5 kg). Among those zoo animals in which a sufficient number of subsequent intra-annual measures had been taken, we assessed visually whether regular, annual fluctuations in body mass were evident. We observed regular, likely seasonal, cycles in body mass, which (i) may be plausibly attributed to ambient temperature changes that affect the body temperature of anteaters, and (ii) would likely not have occurred if the animals were affected by obesity. Additionally, we explain our hypothesis that in the case of giant anteaters, the discrepancy in body mass between natural habitats and zoos most likely is not indicative of a generally obese population in zoos, as is typically concluded in the case of similar comparisons in primates, but represents an unleashing of the full growth potential of the species by conditions of optimal energy and nutrient provision. Future recording of not only body mass but also body dimensions is recommended to better compare the body condition of free-ranging and zoo-managed individuals.

Providing evidence-based care to animals is a common goal in zoos and aquariums. However, there are many understudied species with a lack of information available, which may result in suboptimal care for individuals of these species. Using preference tests to ask individual animals what they want can be an effective means to enhance their care, and subsequently, their welfare. Using 24-h remote monitoring, we assessed substrate, enclosure feature, and lighting preferences of five aquatic turtles (two wood turtles, one Blanding's turtle, and two spotted turtles) that share an indoor enclosure at Lincoln Park Zoo. In addition, we compared enclosure feature and lighting preferences between winter and summer to determine whether the turtles had changing seasonal preferences despite being housed indoors. We found that the wood turtles and Blanding's turtle had substrate preferences, whereas the spotted turtles did not. In addition, we found that the turtles' enclosure feature preferences were consistent between winter and summer, but the amount of time spent on land, logs, and in water varied by individual. Finally, we found that the turtles utilized areas with ambient lighting more than areas with a heat lamp or UV lamp; this was consistent between winter and summer. The turtle preferences observed in this study can contribute to the development of care strategies that support their welfare and, in turn, may inspire similar preference studies at other institutions as we collectively advance toward providing animals of all taxonomic groups with evidence-based care.

While housing nonbreeding all-male social groups of African lion (panthera leo) is a necessary part of managing this polygynous species ex situ, resulting intraspecific agonistic behavior can negatively impact animal welfare and guest experience, undermining two primary objectives of modern zoological gardens. Improvest is a gonadotropin releasing factor analog-diphtheria toxoid conjugate marketed for temporary immunological castration which has proven successful in reducing aggression in other zoo-housed species. To the authors' knowledge, the use of this technique has not been described in male African lions; reticence to use GnRH agonists may stem from concern about phenotypic effects (mane loss) and zoo visitor perception. We describe the use of Improvest in conjunction with other management changes to manage agonism in a coalition of African lions (3.0) housed at the Oakland Zoo. Daily agonism scores were calculated via animal care staff records, fecal testosterone levels were measured, and monthly photos were taken to monitor phenotypic changes. While agonism scores varied seasonally in three pretreatment years, a significant (p < 0.05) reduction in the frequency of agonistic behavior began within 2 months of initial treatment. Two lions showed testosterone suppression within 2 months of receiving the first vaccine, while the third showed suppression beginning in the period 4 months after the first vaccine. Mane loss occurred in all three lions, and time to mane regrowth varied between individuals. Improvest, combined with other management strategies, decreased overall fecal testosterone and intraspecific agonism in these lions, and may be an effective tool in other male coalitions.

Over the past several decades, facultative parthenogenesis (FP)-the ability of a sexually reproducing species to reproduce asexually-in vertebrates has been removed from the realm of obscurity and placed firmly in a position where it warrants focused scientific attention. Likely fueled by increased recognition of the trait, the availability of molecular tools capable of disentangling FP from long-term sperm storage, and the availability of potential cases originating from both zoological and private collections, a wealth of papers has been published revealing the diversity of vertebrate systems in which FP occurs. Specifically, cases have been reported in squamate reptiles (lizards and snakes), crocodiles, birds, and elasmobranch fishes (sharks, rays, and skates). Nonetheless, gaps remain in species documentation, and it is important to analyze and report on new cases. In this paper, we provide a DNA-based analysis confirming FP in a zoo-maintained northern water snake, Nerodia sipedon, a viviparous natricine species that is common and widely distributed in North America. Additionally, we provide information on the sexual development and health of the male parthenogen. Encouragingly, zoological institutions, aquaria, university laboratories, and private collections continue to be rich sources for the further study and documentation of FP in vertebrate species, advancing our understanding of this reproductive trait.

Endemic to only three known provinces in South Central Vietnam, Cuora picturata have faced extensive collection pressures for the food, medicinal, and pet trades. Further exacerbating their decline is the lack of protected areas where wild populations exist, with only one known population occurring within a protected area. With threats to wild populations persisting, the development of an assurance colony has been prioritized for C. picturata. The Asian Turtle Program of Indo-Myanmar Conservation has been operating the Turtle Conservation Center (TCC) in Cuc Phuong National Park since 1998. From 2020 to 2022, 24 C. picturata were acquired by the TCC from the illegal trade. With no ideal repatriation plan, these animals provided an opportunity for developing a captive assurance colony at the TCC to safeguard the species from extinction. As semi-aquatic species, box turtles in the genus Cuora are a unique group that shows variations in habitat use and behavior between species. Herein, we documented some specific courtship behaviors not yet described for C. picturata, providing insight into the unique reproductive behaviors of this species.

Maintaining a diverse gene pool is important in the captive management of zoo populations, especially in endangered species such as the pink pigeon (Nesoenas mayeri). However, due to the limited number of breeding individuals and relaxed natural selection, the loss of variation and accumulation of harmful variants is inevitable. Inbreeding results in a loss of fitness (i.e., inbreeding depression), principally because related parents are more likely to transmit a copy of the same recessive deleterious genetic variant to their offspring. Genomics-informed captive breeding can manage harmful variants by artificial selection, reducing the genetic load by avoiding the inheritance of two copies of the same harmful variant. To explain this concept in an interactive way to zoo visitors, we developed a sonification game to represent the fitness impacts of harmful variants by detuning notes in a familiar musical melody (i.e., Beethoven's Für Elise). Conceptually, zoo visitors play a game aiming to create the most optimal pink pigeon offspring in terms of inbreeding depression. They select virtual crosses between pink pigeon individuals and listen for the detuning of the melody, which represents the realised load of the resultant offspring. Here we present the sonification algorithm and the results of an online survey to see whether participants could identify the most and least optimal offspring from three potential pink pigeon offspring. Of our 98 respondents, 85 (86.7%) correctly identified the least optimal offspring, 73 (74.5%) correctly identified the most optimal, and 62 (63.3%) identified both the most and least optimal offspring using only the sonification.

While translocations of white rhinoceroses have become an important conservation tool, dehydration during long-distance transports has been identified as a welfare concern. Intravenous (iv) fluid administration might therefore be useful to mitigate dehydration; however, special requirements need to be met to make iv fluid administration suitable for large, wild rhinoceroses during transport. Requirements include a portable and robust system that is capable of delivering high flow rates, is easy to set up, and remains patent and operating for long periods of time while allowing the animals to freely stand or lay down in the transport crates. Due to the lack of suitable fluid administration systems, we developed a custom-made system consisting of 8 L drip bags, a three-part, 4.4-m-long, large bore and partially coiled administration set, and a robust, battery-operated infusion pump, which allowed us to successfully administer iv fluids at a maintenance rate of 1-2 mL/kg/h to eight rhinoceroses for 24 h during a mock transport. While iv fluid administration in transported rhinoceroses is time intensive and the large amount of drip bags required during lengthy transports might pose a limitation, the developed system may be useful for the long-distance transport of small groups of rhinoceroses. Furthermore, this system would be of value for injured or sick rhinoceroses, which require parenteral fluid therapy when commercially available infusion pumps cannot provide the large fluid volumes needed.

Conservation breeding programs for endangered species face challenges, notably in the development of husbandry techniques, complicated by the impracticality of conducting controlled experiments. To reduce uncertainty regarding what works in conservation breeding programs, it is essential to capture data. In avian breeding programs, the construction of quality nests and appropriate incubation and handling of eggs by the parents are essential prerequisites to the successful production of offspring. Here, we study factors influencing nest-building and parental incubation outcomes in 'alalā (Corvus hawaiiensis), which is extinct in the wild and numbers fewer than 130 individuals in human care. Using parent-incubated egg data from 2018 to 2021 (171 clutches, 55 pairs), we evaluated the role of husbandry factors in determining the quality of nests constructed by 'alalā and the likelihood of nest quality and other social and environmental factors to predict egg loss (breaking, cannibalization, or ejection of an egg from the nest). More than half of all eggs laid failed to reach the hatch date. Nest quality was the most influential predictor of egg loss, with eggs in higher quality nests more likely to reach the hatch date. Male age also influenced egg loss, with very young (3 years old) and older males (⪞12 years old) experiencing more egg loss. Furthermore, the two facilities and two aviary types also differed in the quality of nests 'alalā constructed, indicating that nest-building behavior can be influenced by husbandry practices. These findings reduce uncertainty and provide insights for recommended management interventions to facilitate successful reproduction in human care.

The mode of reproduction most often seen in snakes is sexual, but studies have noted facultative parthenogenesis in at least six families. Here, we provide evidence for the first observed case of facultative parthenogenesis in a captive Jamaican boa (Chilabothrus subflavus). A 7-year-old female Jamaican boa, isolated since birth, was found to have produced a litter of 15 offspring. To provide molecular DNA evidence of parthenogenesis, 13 new microsatellite loci were isolated in the species. All offspring were found to be homozygous at each locus and only possess alleles found in the dam, implicating that they were born from asexual reproduction. Several developmental abnormalities, including stillbirths and spinal deformities, were noted in the litter which may be explained by their increased level of homozygosity. To preserve genetic diversity in the captive population, research should be conducted to understand the prevalence of this mode of reproduction and to guide future management decisions of this IUCN listed Vulnerable species.