Zoological institutions strive to foster positive visitor perceptions regarding the welfare of animals under their professional care. However, the impact of specific messaging and terminology used in educational signage and programs remains unclear. The goal of the current studies was to examine the favorability and impact of common terminology around the topics of animal care and welfare used within zoos and aquariums. Participants were randomly selected from Brookfield Zoo Chicago's household member database and invited via email to complete a brief survey. Study 1 employed a feeling thermometer to assess the favorability of common zoological terms. Studies 2-7 utilized vignettes to examine terminology through both feeling thermometers and Likert-type scales, measuring both favorability and visitor perceptions of animal care and welfare. Results from Study 1 suggest that there are some statistically more favorable terms that zoological facilities could use when interpreting different topics for visitors. These include professional care, habitat, animal health, veterinary care, animal care specialist, and animal care professional. However, Studies 2-7 demonstrated that when comparing the terms within contextual vignettes, the significant differences in favorability no longer existed. Results can be utilized by practitioners in zoos and aquariums to choose more favorable terms when discussing animal care and welfare. Only through sound science will we better understand how best to impact zoo and aquarium visitors' perceptions of animal welfare.

From May 2016 until December 2018, a group of blacktip reef sharks (Carcharhinus melanopterus) at Shedd Aquarium successfully produced six litters. These multiple successful breeding events provided the opportunity to develop and characterize microsatellite loci in this species to properly identify paternity for future studbook succession. Thirteen microsatellite loci were developed to determine the paternal lineages of all six litters born to four female and three male blacktip reef sharks. Of the six litters produced, three were the result of polyandrous mating, including one litter that was sired by all three males. While some females only produced one litter during the study, other females exhibited a biennial reproductive cycle. Although all three males had equal opportunity to mate with various females, one male sired over half of the offspring produced during this 2-year period. This study highlights the importance of using paternity analysis as a tool to aid in studbook management and future ex situ population conservation decisions.

Research on positive animal welfare has prompted exploration and implementation of methods to stimulate the behavioral repertoires of zoo-housed species. We investigated the impact of a modified feeding method on the behavioral diversity, activity budgets, and social relations of five African lions at Zoo Antwerpen. The original method involved daily individual feedings indoors while the modified method provided group feedings three times a week outdoors. Observations spanned 6 weeks (3 weeks per method and a 1-week habituation period in between), yielding 150 h of behavioral data using continuous focal sampling. Results indicated a significant increase in behavioral diversity with the modified method across all observed time (p < 0.001). This was accompanied by an increase in active (for females, p < 0.001) and exploratory behaviors (p < 0.001). Time spent feeding did not change significantly. Inactivity levels shifted (p < 0.001), aligning more closely with natural wild lion behavior patterns. In the modified method, lions spent more time feeding and exploring on feeding days compared to fasting days (p < 0.001 and p = 0.009). Inactivity was lower on feeding days (p = 0.001), while overall activity levels did not change significantly. Social network analyses showed no significant changes in agonistic or affiliative behaviors, indicating the feeding method change had limited effects on social relations. In conclusion, our study underscores the importance of feeding methods in promoting natural behaviors and enhancing welfare outcomes for zoo-housed African lions, emphasizing the need for tailored management strategies to support natural behaviors and welfare.

Territorial advertising in lions involves a suite of behaviors such as patrolling, scent marking, spraying, and vocalizing. In their native tropical habitat, wild lions are primarily nocturnal, capitalizing on cooler temperatures and darkness for effective hunting and minimizing thermoregulation stress. By extension, their territorial behaviors, notably the striking vocal advertising known as "roaring," are predominantly nocturnal. However, atypical diurnal territorial activity has been reported for captive lions in some captive settings, including Fota Wildlife Park (FWP) in Ireland. This study investigates the influence of seasonal weather conditions on the temporal distribution patterns of territorial vocalizations by a pride of captive Asiatic lions living at high latitudes in FWP, where extended audio recordings were regularly made from mid-summer to mid-winter 2021. Consistent with typical behaviors of their wild counterparts in the tropics, the captive lions at FWP exhibited persistent crepuscular peaks of roaring activity throughout the study. However, as the seasons passed, these peaks of roaring activity immediately after sunset and, to a lesser extent, just before dawn clearly followed the substantial seasonal changes in the timing of these two daily synchronizing stimuli at such high latitude. While most roaring activity occurred during the hours of darkness, consistent with prior observations at FWP during the winter, they nevertheless also roared at all hours of the day throughout all seasons, including the summer months. Persistent daytime territorial vocalizations in captive settings are therefore probably more likely related to environmental factors other than cool weather in this temperate captive setting.

In the Northern Hemisphere, white-naped cranes breed from April to early June. Females typically produce two eggs per clutch with each season having one to four clutches per year. Egg production beyond the species' natural output can significantly impact an individual's health as significant amounts of calcium are required to form the eggshell. The objective was to evaluate the effectiveness of deslorelin acetate (Suprelorin) in suppressing gonadal function and egg production of a 39-year-old female white-naped crane with a history of long breeding seasons and excessive egg laying. Deslorelin acetate (9.4 mg) implants were administered s.q. at 1- or 3-month intervals over four breeding seasons. Fecal samples were collected 1-3 times/week and gonadal hormones were extracted and analyzed. Egg production was recorded. Analysis showed that deslorelin acetate (9.4 mg) implanted s.q. twice at a 3-month interval beginning at the expected start of the breeding season was not fully effective in suppressing gonadal function and egg production. The following breeding season, three deslorelin acetate 9.4 mg implants were administered at ~1-month intervals beginning at the expected start of the breeding season. This protocol was more effective at suppressing gonadal hormone production and egg production. Our results demonstrate a timeseries of how deslorelin acetate impacts reproductive function in white-naped cranes, though further studies should include the effects of implant after cessation.

Close animal encounters potentially increase visitor connection to species and present an educational and fundraising opportunity. However, evidence of the impacts on animal welfare or visitor education is limited. Red panda (Ailurus Fulgens spp.) encounters are gaining popularity despite a lack of research on their effects. As red panda are a characteristically cautious species and prone to disturbance, concern has been raised as to their suitability for encounters. We examined the extent and composition of red panda encounters amongst 150 Global Species Management Plan (GSMP) member zoos (survey responses), and their impact on longevity and reproduction (species 360 analysis). Over a third (39%) of zoos surveyed offered red panda encounters, with most (71%) being animal feeding experiences. Educational information was provided in almost all cases (95%) and focused on the encounter individuals and species' natural history. Of the 31 encounter red panda who were also part of a breeding program, 24 reproduced. Comparative data analysis suggested that encounter red panda produced more offspring and had higher longevity (survival) than non-encounter individuals, although this may reflect changes in red panda husbandry over time. A. f. styani were less likely to breed and produced fewer offspring than A. f. fulgens. Whilst there appears to be no major negative impacts of red panda encounters, continued monitoring and ensuring high animal-welfare standards remains vital.

Klinefelter's syndrome is the most prevalent sex chromosomal disorder in humans and has been observed in various mammalian species. This article documents the case of a 25-year-old western lowland gorilla (Gorilla gorilla gorilla) at Longleat Safari Park who was diagnosed with Klinefelter's syndrome. The study encompasses their diagnosis, behavioral assessment, and management strategies over twelve years. The behavioral profile includes neophobia, sensitivity to sounds, impaired problem-solving abilities, mood swings, and atypical social interactions. Management practices tailored to his condition involved establishing a consistent daily routine, mitigating exposure to sudden noises, and pre-emptive medical interventions at early signs of illness. These approaches have effectively addressed his unique needs and reduced stress-related behaviours. This case study underscores the necessity for individualized care plans for nonhuman primates with Klinefelter's syndrome, providing a guide for future management of similar cases in captivity. The findings contribute to the limited knowledge of Klinefelter's syndrome in gorillas and highlight the importance of personalized and consistent management strategies to enhance the welfare of affected individuals.

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.

The Harpy Eagle (Harpia harpyja), one of the largest birds of prey in the world, is threatened with extinction throughout its entire area of occurrence in the Neotropics. While conservation efforts for the wild populations are crucial, it is also important to focus on ex situ conservation actions. To achieve this, understanding the genetic characteristics of the captive population is essential to prevent inbreeding and loss of genetic diversity over time. In this study, we employed a next generation sequencing strategy to develop a new set of primers for microsatellite regions specific to the Harpy Eagle. These markers were validated in Harpy Eagle individuals maintained in captivity at Brazilian zoos and conservation institutions. We characterized these captive individuals using ten highly polymorphic microsatellite loci to estimate relatedness and individual identification at > 95% accuracy. The same effect can be achieved with four loci. Additionally, we developed a statistical test to further refine relationship estimates. Paired with robust sex markers, the new set of microsatellite markers presented here the potential to guide ex situ management strategies, aiming for better reproductive pairings and the maintenance of genetic diversity of the Harpy Eagle.

The crab-eating fox (Cerdocyon thous) is an omnivorous species with a frugivorous/insectivorous feeding habit and low feeding specificity, consuming a wide range of prey and vegetation. Studies that include its diet are based on the analysis of stomach and fecal content of free-living animals, without focusing on nutrient intake. Thus, the aim of this study was to evaluate nutrient intake and its use in a diet formulation provided to crab-eating foxes kept under human care. Eight healthy crab-eating foxes received a diet formulated with fruits (papaya, banana, apple and mango), commercial dog food, boiled egg, chicken neck, bovine heart, and a multivitamin supplement. The animals received the same diet for at least 1 year. Food intake was monitored, and a total fecal collection was carried out. The macronutrient composition of diet and feces was analyzed and macronutrient intake and digestibility were evaluated. The average of apparent digestibility coefficients was 84.0% for dry matter, 31.75% for ash, 95.63% for ether extract, 81.88% for crude protein, 58.13% for crude fiber, 85.38% for nitrogen free extract (NFE), and 85.25% for gross energy (GE). The results showed that the individuals are taking advantage of sufficient amounts of almost all nutrients. Evaluating the nutritional content and utilization of diets in animals under human care is essential, as it allows for adjustments to ensure the maintenance of an ideal body condition score.

White rhinos (WR, Ceratotherium simum) are grazers and black rhinos (BR, Diceros bicornis) are browsers; this difference has been related to BR being more challenging in terms of husbandry. Previous reports indicated that BR in zoos often receive diets with a higher proportion of easily digestible compounds compared to other rhino species. Additionally, BR are susceptible to iron overload disorder (IOD). We compared the feeding methods and recommendations, and sampled diets and feces of 117 WR and 82 BR across 41 European zoos. The few available data for free-ranging animals were also incorporated. The percentage of forage in the total estimated dry matter intake was 93% for WR and 77% for BR, matching fecal parameters indicating a higher diet digestibility in BR. BR received higher levels of (pelleted) compound feeds and produce than WR. Nevertheless, dietary fiber levels were similar to that reported for free-ranging specimens in both species. Zoo diets were higher in several minerals (Na, P, Cu, Zn) than natural diets. However, zoo BR received diets with similar iron content to that described in free-ranging BR diet items and fecal iron levels were not higher than those in the few samples of free-ranging BR available, suggesting that iron levels in zoo BR diets are not overly excessive. Consequently, IOD appears to be more complex, associated with iron bioavailability and possibly non-dietary causes. Grass hay was used in 100% of WR and 36% of BR (all BR facilities used lucerne hay). BR feces had levels of abrasive silica comparable to those of free-ranging WR and much higher than free-ranging BR, matching reports of excessive tooth wear in adult BR. Browse provision for BR could not be quantified but appeared low in general; no alternative forages (like sainfoin) were fed. Efforts to consistently provide high amounts of browse to BR must be increased and forage should be low in iron and abrasive silica.

Molecular genetic studies have revealed extra-pair paternity (EPP) in monogamous avian species including several penguin species. Therefore, this study investigated the parentage of captive gentoo penguins (Pygoscelis papua) in Japanese zoos and aquariums by analyzing 10 microsatellite loci. A total of 200 relationships between parents and offspring from the studbook were created through behavioral observations. Three of these cases (1.5%) showed mismatched genotypes between the father and offspring in at least three loci, thereby suggesting the possibility of EPP. In two of the three cases, the true (genetic) fathers were inferred from male individuals who lived with their mothers during the breeding season. The EPP frequency in the captive population was lower than that previously reported for wild populations. The results of this study demonstrate that the genetic approach effectively validated the accuracy for studbook of captive avian species.

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.

Polar bear (Ursus maritimus) neonates are highly altricial, and in-den maternal care is required for cub survival and as follows, population health. Study of maternal denning polar bears in managed care can provide valuable insights on mother-cub dynamics. We reviewed video recordings of polar bears in maternal dens from three participating zoos to monitor maternal behavior and cub development. The study subjects included three polar bear mothers with a single cub. During a total of 366 observations, we collected behavioral data on both mother and cub during 30-min observation sessions spaced every 4 h for the first 30 days post-partum. We recorded mother-cub contact and individual behaviors for both the mother and cub. During the first ten days postpartum, cubs spent 60% of the time on their mother, usually in a cradled position, and this behavior decreased to 44% thereafter. Mothers and cubs spent most of the time resting, with mothers occasionally licking and attending to their cubs. Cubs spent approximately 12% of the time nursing. More replicates from ex situ populations will refine our understanding of how the denning environment, maternal care behavior and cub development are correlated with cub survival.

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.

Magellanic penguins (Spheniscus magellanicus) are migratory and the most abundant penguin species occurring in Brazil. Anthropogenic threats compromise their winter migration, leading to a significant number of debilitated individuals to be stranded on Brazilian beaches. Rescued penguins are taken to rehabilitation centers for medical treatment and evaluated for reintroduction; if non-releasable, they are either euthanized or kept in permanent captivity. Obtaining sufficient blood volume is critical for the accurate diagnosis and ongoing management of many diseases and health conditions. Moreover, blood drawing in Sphenisciformes can be challenging, particularly in severely debilitated penguins. Here we describe an alternative technique for blood collection in Magellanic penguins through the dorsal coccygeal vein, which is suitable for both debilitated and healthy animals. Although the coccygeal vein is not a standard site for blood collection in penguins, it may be considered as an alternative if peripheral veins are presenting very low pressure or have been exhausted/inaccessible.

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.

To offset monarch butterfly (Danaus plexippus) habitat loss, conservation organizations encourage planting monarch-friendly plants and often distribute seed packets and plants to provide materials for habitat creation. However, there is little known on the outcomes of these complimentary materials, despite the opportunity to measure direct conservation action. Six public outreach events hosted by Oklahoma City Zoo occurred from 2016 to 2023. Participants at each event were invited to pledge to plant monarch habitat and in exchange received complimentary materials. Participants were surveyed 2-3 months post-event to follow-up on outcomes of materials distributed as well as measure monarch butterfly knowledge post-event. Visitors reported planting milkweed plants at higher rates than seeds and visitors' post-event knowledge of monarchs was high. This study demonstrates that overall return on investment, measured by pro-environmental behavior, is lower when purchasing seeds compared to purchasing milkweed plants. Overall, outreach programs that distribute complimentary seeds/plants have the potential to create habitat and create positive conservation action outcomes.

Among European Association of Zoos and Aquaria (EAZA) Ex-situ Programs (EEPs), both African and Asian elephant populations represent good models of the benefits of collective, unified action to contribute to the conservation of threatened species. However, the management of mature male elephants poses distinct challenges for both population sustainability and animal wellbeing. Identifying the goals and challenges of institutional members as they relate to male elephant management will inevitably aide in the planning of future management strategies and identify areas for collaboration with other ex-situ elephant populations. The purposes of this study were (1) to survey EAZA facilities housing adult male elephants to understand institutional priorities around musth management, male socialization, and semen collection to compare them to population-wide recommendations; and (2) to compare patterns to those obtained from a recent survey of Association of Zoos and Aquariums (AZA) accredited facilities. We received responses from 55 facilities, holding 76 adult male elephants. The highest priorities were natural breeding and male socialization; assisted reproductive techniques (e.g., semen collection) were not prioritized at the institutional level, despite emphasis by the EEPs. Further, while most facilities acknowledged the importance of managing elephants around musth, few had formalized monitoring programs. Compared to AZA institutions, EAZA facilities had similar goals and challenges, with lower reliance on and capacity for collecting semen. These results underscore the specialized care that male elephants require to achieve population sustainability and uphold high animal welfare standards, with clear opportunities for knowledge sharing with AZA counterparts.

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.

Zoos fill an important role in connecting humans with nature, especially given an increasing rate of both urbanization and biodiversity loss. With the advent of new technologies, however, there are many alternatives to experiencing biodiversity firsthand. We tested if the type of animal encounter at a zoo (in-person animal viewing without touch, in-person animal viewing with touch, or video-recorded animal viewing) and/or animal species (elephant or stingray) affected zoo visitor knowledge, emotional affect, empathic concern, and/or conservation intent. A total of 300 zoo members were randomly assigned to 6 different animal encounter conditions. We found that participants who viewed video-recordings of animals had significantly lower scores on all outcomes, except knowledge, than those who viewed animals in-person. There were no significant differences between in-person animal viewing without touch and in-person animal viewing with touch. Moreover, we found that stingray participants had lower scores on all outcomes compared to elephant participants. We suggest extensions of this study and discuss potential implications for the future role of zoos.