Zoo Biology最新文献

To manage ex situ breeding populations effectively, it is important to understand the factors that may lead to reproductive failure. In this study, we aim to understand factors associated with reproductive success in zoo-housed bush dogs (Speothos venaticus), and form evidence-based recommendations for their breeding management. We distributed a survey to global institutions housing bush dogs to collect data on factors which may affect litter survival. Responses were obtained from 30 zoos across 13 countries, providing data on 125 litter births between 2012 and 2022. Information from the Zoological Information Management System (ZIMS) and studbook records supplemented this dataset. We found that within northern temperate regions, the number of pups reared to the age of 1 month in bush dog litters (n = 112 litters) is linked to the ages of breeding individuals, prior breeding experience of females and birth season. The number of pups reared per litter declines with advancing maternal age, but this decline can be reduced by pairing with an older male; experienced females rear more pups per litter than inexperienced females, and litters born in the summer have better survival outcomes than other seasons. Sharing data between zoos provides greater statistical power to identify challenges associated with breeding lesser-researched species, allowing zoos to overcome these challenges through evidence-based management changes.

Human behavior change is needed to stop the triple planetary crisis. Zoos reach millions of people every year and there is evidence available that people do change their behavior because of zoo led interventions. Designing interventions with behavior change frameworks in mind can increase the efficacy of interventions. The Behavior Change Wheel is a guide for describing, designing and evaluating behavior change strategies, rooted in the COM-B model. It can be used for retrospective assessment of existing interventions. Here we present a content analysis of websites of members of the British and Irish Association of Zoos and Aquariums (BIAZA). We classified behavior change projects in relation to categories on the Behavior Change Wheel including Intervention Function and Policy Category. A total of 754 behavior change projects were identified and analyzed, resulting in 1650 Intervention Function and 1154 Policy Category codes. Persuasion (n = 450) and Education (n = 289) were the most frequently identified Intervention Functions. Communication/marketing (n = 515, 68.30%), was the most frequently used Policy Category. Zoos themselves were most often the agents of behavior change and projects most frequently targeted the general public. Most projects used multiple intervention functions in conjunction with each other, with only 12.73% (n = 210) of Intervention Functions occurring on their own. Combining Intervention Functions has positive implications for intervention effectiveness, but barriers to effectiveness such as limited project targets were identified. Developing behavior change projects in zoos with behavior change frameworks in mind would likely further increase the effectiveness of these projects.

Training is an essential part of meeting the needs of elephants in human care. In particular, training in a protected contact environment inherently offers more control over the environment and the choice to perform requested behaviors, likely improving welfare. Here we present a follow-up assessment of caregiver and elephant behavior nearly 20 years after the initial transition from free to protected contact to explore any longitudinal changes and the potential effects of moving to a newly constructed exhibit. As with the previous study examining the initial transition to protected contact, the present study reports high levels of compliance with caregiver requests, even after nearly two decades and through a major transition in the environment. We propose that implementing longitudinal studies to periodically evaluate training programs and develop best practices for meeting the needs of elephants in human care are an important contributor to elephant welfare.

Primate social behaviors are known to mitigate a number of negative psychological and physiological problems. Social connectedness in wild baboons can predict longevity and health, but the relationship between social grooming and physical health in captive baboons is less known. We studied rates of social grooming in captive olive and olive/yellow hybrid baboons (Papio anubis; P. anubis/cynocephalus), the factors that influence social connectedness, and its potential impacts on health as measured with neutrophil and lymphocyte levels. These white blood cell measures are available through routine bloodwork and the neutrophil-to-lymphocyte ratio (NLR) is known to be predictive of health outcomes. Subjects were 162 adult baboons housed in groups consisting of 1 male, 3 to 12 females, and associated offspring. Four 30-min all-occurrence observations per group were used to collect behavioral data. Blood data was collected opportunistically during veterinary check-ups for 45 of the females. Despite group compositions differing significantly from those in the wild, the captive baboons exhibited some similar patterns of social grooming and social connectedness to those of wild baboons. NLR was not significantly associated with any measure of social connectedness initially assessed, but a relationship between social network size and lymphocyte levels emerged. Baboons with few social grooming partners exhibited an expected decline in lymphocyte levels with age, but baboons with many social grooming partners did not show this expected trend. It appears, therefore, that older female baboons with many social partners may be buffered against age related immune health declines and that social connectedness is potentially acting to mediate some of the detrimental effects of aging.

Zoos are interested in assessing the well-being of the animals in their care, including potential impacts from environmental and anthropogenic factors which could alter welfare. Zoos also provide a unique environment whereby visitors can get within proximity to wild animals, which can have positive, neutral, or negative impact for the exhibited animal's welfare. Within zoo settings, there has been little research published on these welfare impacts for reptiles, specifically snakes. Additionally, there is limited knowledge on their behavior in relation to captive welfare. Three snakes were selected, and conditions were implemented outside of their habitats to alter visitor proximity. The three conditions experimentally altered the proximity of people near the snake habitats and included Visitor-Natural (regular visitor proximity), Visitor-Control (no visitors within a 210 cm radius), and Visitor-Experimenter (an experimenter within close proximity throughout the observation time). An ethogram was developed and measured across a within-subject reversal design for all three conditions. Results indicated that overall, there was a neutral to positive impact of the Visitor-Natural condition. However, the highest negative impacts were observed during the Visitor-Experimenter condition, including increased abnormal behaviors. This study suggests that snakes will habituate to people but may be affected by short-term, unpredictable behavior from visitors. The results are discussed in terms of visitor impacts on exhibited snakes, as well as implications for assessing overall snake welfare.

Limiting stress during interactions between captive animals and humans is important for effective husbandry. One physiological change during the vertebrate stress response is the release of glucocorticoid hormones. Here, we measured plasma corticosterone in female domesticated budgerigars (Melopsittacus undulatus) to test whether human presence, restraint, or removal and return of a newly stressed neighbor increases corticosterone. The presence of humans for 15 min at the beginning of the experiment did not significantly elevate corticosterone above baseline levels, suggesting that birds that acclimate to humans are minimally affected by their presence. However, at the end of the experiment after multiple blood sampling events, the same human presence test significantly elevated corticosterone above baseline and human presence levels measured at the beginning of the experiment. Thus, repeated blood sampling could cause progressively stronger stress responses to human presence. Restraint-induced corticosterone levels were significantly higher than all other treatments, indicating that human handling activates the stress response. After stressed birds were returned home, corticosterone levels of their neighbors were significantly higher than baseline at 25- and 45-min post-return. However, the 25- and 45-min corticosterone levels were not significantly different from each other, or levels induced by human presence at the beginning or end of the experiment. This outcome suggests that social transmission of stress was limited across the sampled time frame. These data highlight the importance of evaluating the costs and benefits of different human-animal interactions in captivity, including in domesticated species that are more tolerant of forced proximity to humans.

The concept of choice is increasingly recognized as a critical component of animal welfare, particularly within zoological settings. Despite its significance, the academic literature on empirically examined methods to allow zoo animals to actively communicate choice is limited. This paper presents a novel "You Choose" procedure that allowed multiple pinniped species-including New Zealand fur seals (Arctocephalus forsteri), California sea lions (Zalophus californianus), and an Australian sea lion (Neophoca cinerea)-along with Pacific bottlenose dolphins (Tursiops truncatus) to communicate choice between concurrently-presented options through the autonomous selection of one outcome. We describe two different scenarios in which this choice procedure was implemented: (1) To select among potential rewards during a training session; or (2) to allow the animal to pick between potential enrichment items. In both cases, training the animal to utilize the "You Choose" procedure is detailed, with the purpose of providing the animal the ability to make such choices. Training zoo animals to communicate choices to keepers from an array of concurrently available stimuli should support the animals' welfare needs, as well as introduce a framework for implementing choice-driven training and enrichment practices that can be adapted for other zoo-housed species. We propose a future methodological approach utilizing the "You Choose" procedure which allows for measurable choice manipulations, thereby suggesting future research opportunities to assess the quantitative impact of choice on welfare.

The body mass of zoo animals may differ from those in wild populations due to the different environmental and dietary conditions being offered under human-managed care. These differences in body mass may impact health at both individual and population levels. In the case of rhinoceroses, this is relevant because of the distinct feeding requirements of each species and their susceptibility to obesity when inappropriate diets are offered. Here we attempt a comparison between the adult body mass records of the global zoo populations of rhinoceroses (white Ceratotherium simum, black Diceros bicornis, and greater one-horned Rhinoceros unicornis) and the available body mass records of free-ranging specimens in the literature. Body mass data from free-ranging specimens is surprisingly scarce for white and greater one-horned rhinos. Most adult zoo rhinoceroses are within the body mass range described for wild populations except female white rhinoceroses, which are, on average, heavier than free-ranging females. Also, contrary to what has been described for natural habitats, zoo rhinoceroses do not show evidence for seasonal fluctuations in body mass, most likely due to the consistent nutrient supply in zoos. While obesity might be present across female white rhinos, and exacerbate other underlying health issues at the individual level in other taxa, this particular data set does not provide evidence that obesity is a population-level phenomenon in black or greater one-horned rhinos. Our findings should not weaken the efforts towards improving zoo rhinoceros nutrition and body condition monitoring.

Singing is an ecologically important behaviour for songbirds. Syllables function as the building blocks of birdsong, so changes to their production will have implications for overall song structure. It is well established that anthropogenic disturbance can influence syllable production in wild songbird populations, but the effect of anthropogenic disturbance on syllable production in ex situ populations has not been studied. We set out to fill this gap by comparing the syllable production of Chester Zoo's Bali myna (Leucopsar rothschildi) population during a period of zoo closure in 2020 (due to the COVID-19 lockdown) to a period of normal zoo opening in 2019. The number of syllables per song, the rate at which syllables were produced and the diversity of syllables all showed evidence of plasticity across days and years. However, only the number of syllables per song responded significantly to anthropogenic disturbance. Changes in syllable number due to anthropogenic disturbance could mitigate potential signal masking from unpredictable noise, although communication efficacy may still be affected. As a result, changes in vocal communication could impact conservation breeding programmes by altering the way that individuals interact with conspecifics.

Managing for positive animal welfare is recognized as a fundamental zoo and aquarium practice. Indeed, many zoo and aquarium associations now have expectations that their members demonstrate achievement of some level of positive welfare for their charges. These organizations encourage the consideration of animal welfare outcomes in all forms of decision making, from those directly influencing individual animals - such as relocations and breeding recommendations, to those that may or may not have downstream effects on animal welfare - such as evening events or business hours. Perhaps driving these expectations, animal welfare science has begun to develop a deeper understanding and emphasis on the role of emotion in animals' lives. Welfare is now widely considered to be synonymous with emotional state. We have noticed though, that there are occasions when presumed animal welfare concerns may reflect caretakers' own emotionally driven perceptions of how certain decisions may impact animals' welfare. These "gut felt" impressions are generally not supported with data, often do not reflect best practice, and appear to be based on assumptions that reflect personal feelings. They also seem based on the supposition that current welfare is good welfare and tend to imply that changes in welfare are to be avoided, though they do not recognize that welfare can, at times, be different but equal or less but still positive. In short, the looming ghosts of animal welfare, past, present, and future appear to drive decision-making about animal welfare even when tangible, reliable data suggest alternative courses of action.