Birds Kept in the German Zoo “Tierpark Berlin” Are a Common Source for Polyvalent Yersinia pseudotuberculosis Phages

Yersinia pseudotuberculosis is an important animal pathogen, particularly for birds, rodents, and monkeys, which is also able to infect humans. Indeed, an increasing number of reports have been published on zoo animals that were killed by this species. One option to treat diseased animals is the application of strictly lytic (virulent) phages. However, thus far relatively few phages infecting Y. pseudotuberculosis have been isolated and characterized. To determine the prevalence of Y. pseudotuberculosis phages in zoo animals, fecal samples of birds and some primates, maras, and peccaries kept in the Tierpark Berlin were analyzed. Seventeen out of 74 samples taken in 2013 and 2017 contained virulent phages. The isolated phages were analyzed in detail and could be allocated to three groups. The first group is composed of 10 T4-like phages (PYps2T taxon group: Myoviridae; Tevenvirinae; Tequatrovirus), the second group (PYps23T taxon group: Chaseviridae; Carltongylesvirus; Escherichia virus ST32) consists of five phages encoding a podovirus-like RNA polymerase that is related to an uncommon genus of myoviruses (e.g., Escherichia coli phage phiEcoM-GJ1), while the third group is comprised of two podoviruses (PYps50T taxon group: Autographiviridae; Studiervirinae; Berlinvirus) which are closely related to T7. The host range of the isolated phages differed significantly. Between 5.5 and 86.7% of 128 Y. pseudotuberculosis strains belonging to 20 serotypes were lysed by each phage. All phages were additionally able to lyse Y. enterocolitica B4/O:3 strains, when incubated at 37°C. Some phages also infected Y. pestis strains and even strains belonging to other genera of Enterobacteriaceae. A cocktail containing two of these phages would be able to lyse almost 93% of the tested Y. pseudotuberculosis strains. The study indicates that Y. pseudotuberculosis phages exhibiting a broad-host range can be isolated quite easily from zoo animals, particularly birds.

Welfare Assessment Tools in Zoos: From Theory to Practice

Zoos are increasingly putting in place formalized animal welfare assessment programs to allow monitoring of welfare over time, as well as to aid in resource prioritization. These programs tend to rely on assessment tools that incorporate resource-based and observational animal- focused measures since it is rarely feasible to obtain measures of physiology in zoo-housed animals. A range of assessment tools are available which commonly have a basis in the Five Domains framework. A comprehensive review of the literature was conducted to bring together recent studies examining welfare assessment methods in zoo animals. A summary of these methods is provided with advantages and limitations of the approach es presented. We then highlight practical considerations with respect to implementation of these tools into practice, for example scoring schemes, weighting of criteria, and innate animal factors for consideration. It is concluded that would be value in standardizing guidelines for development of welfare assessment tools since zoo accreditation bodies rarely prescribe these. There is also a need to develop taxon or species- specific assessment tools to inform welfare management.

Human Positioning in Close-Encounter Photographs and the Effect on Public Perceptions of Zoo Animals

With the rising popularity of social media, conservation organisations and zoos need to understand its impact on public perceptions of the animals they house and their role in conservation. In addition, many zoos offer close-encounter experiences, and visitors frequently share images from these experiences online. This study measured the effects that viewing such encounter images had on public perceptions of both the zoo and the animals they saw. One of sixteen images was randomly presented to participants in two samples: one of Zoo Community followers and members of Zoos Victoria (n = 963), and a representative sample of the Australian public (n = 1619). Each image featured one of four animals (Eclectus parrot, Kangaroo Island kangaroo, Monteith’s leaf insect, Centralian carpet python) and one of four human positions (human and animal touching, human and animal ~30 cm apart, human and animal ~1 m apart, animal alone). Results indicated that viewing different animals and the different human positions within these human–animal encounter images can affect public perceptions of zoo animals. In particular, the closer the proximity of a human to an animal in an image, the more likely respondents were to think that the animal was not displaying a natural behaviour and the more likely it was for General Public respondents to think that the animal would make a good pet. These findings can be used by zoos, wildlife tourism, and media organisations to ensure that they are sending clear, positive, and intended messages about zoo facilities and animals, as well as providing insights into animal encounter images in wider settings.

Evaluating Environmental Enrichment Methods in Three Zoo-Housed Varanidae Lizard Species

Environmental enrichment has been shown to enhance the behavioural repertoire and reduce the occurrence of abnormal behaviours, particularly in zoo-housed mammals. However, evidence of its effectiveness in reptiles is lacking. Previously, it was believed that reptiles lacked the cognitive sophistication to benefit from enrichment provision, but studies have demonstrated instances of improved longevity, physical condition and problem-solving behaviour as a result of enhancing husbandry routines. In this study, we evaluate the effectiveness of food- and scent-based enrichment for three varanid species (Komodo dragon, emerald tree monitor lizard and crocodile monitor). Scent piles, scent trails and hanging feeders resulted in a significant increase in exploratory behaviour, with engagement diminishing ≤330 min post provision. The provision of food- versus scent-based enrichment did not result in differences in enrichment engagement across the three species, suggesting that scent is just as effective in increasing natural behaviours. Enhancing the environment in which zoo animals reside is important for their health and wellbeing and also provides visitors with the opportunity to observe naturalistic behaviours. For little known and understudied species such as varanids, evidence of successful (and even unsuccessful) husbandry and management practice is vital for advancing best practice in the zoo industry.

Effects of active and passive enrichment regimes on fecal glucocorticoid metabolite levels in captive Indian leopards (Panthera pardus fusca)

Environmental enrichment improves health and wellbeing of zoo animals. To test this hypothesis, we used Indian leopards, one of the popular zoo animals, as a model system to understand effects of active (interacting) and passive (noninteracting) enrichment elements on stress hormone levels of captive individuals. We included three enrichment categories, category ‘A’ (having both active: large size cage, and passive: controlled temperature, playback of forest sounds and sound proof glasses to filter visitors’ noise, enrichment elements), category ‘B’ (active enrichment type I, small size cage with air coolers), and category C (active enrichment type II, medium size cage without air coolers) for the leopards (n=14) housed in two Indian zoos. We standardized a non-invasive method to measure fecal glucocorticoid metabolite (fGCM) levels in captive leopards. The standardized fGCM assay was further validated by analysing samples from free-ranging leopards, as well. The fGCM levels (Mean±SE) were 10.45±2.01 and 0.95±0.003μg/g dry wt of feces in captive and free-ranging leopards, respectively. Our results demonstrated that fGCM levels of leopards in categories B and C were significantly (P<0.05) different from each other, thus, indicating cage size (an active enrichment element) as an important factor in influencing the physiology of the sampled animals. Overall, the findings of the study will contribute towards informing policies for management of the Indian leopards.

The Effect of Visitors on Zoo Reptile Behaviour during the COVID-19 Pandemic

Visitors to zoos can have positive, neutral, or negative relationships with zoo animals. This makes human–animal interactions (HAIs) an essential component of welfare and an important consideration in species selection for zoo exhibits and in enclosure designs. We measured the effect of visitors on reptiles by comparing open and closed periods during the lockdowns in response to the COVID-19 pandemic in the UK in a low-resolution dataset for thirteen species of reptiles and a high-resolution dataset focussing on just one of these. Scan sampling on thirteen reptile species (two chelonians and eleven squamates) showed species-specific differences in response to the presence/absence of visitors, with most taxa being only weakly affected. High-resolution scan sampling via video footage of an off-show and on-show enclosure was carried out for tokay geckos (Gekko gecko) over the open and closed periods. In this part of the study, tokay geckos were significantly more visible during zoo closure than when visitors were present on-exhibit, but there was no change in off-show animals, indicating the effect of visitors as opposed to other factors, such as seasonality, which applied equally to both on- and off-show animals. The high-resolution study showed that a significant effect was present for tokay geckos, even though the low-resolution suggested that they were more weakly affected than other taxa. Our results indicate that, for cryptic species such as this, more intensive sampling may be required to properly understand visitor effects. Our data do not allow the interpretation of effects on welfare but show that such assessments require a species-specific approach.

Behavior and Habitat Use Remain Diverse and Variable in Modern Zoological Exhibits over the Long-Term: Case Studies in 5 Species of Ursidae

Long-term evaluations of whether modern zoological exhibits help to maintain variation in the behavior of zoo animals are lacking despite the hope that animals avoid falling into monotonous patterns of behavior or boredom. This study evaluated changes in behavior and habitat use over multi-year periods in nine individuals of five bear species at two zoological facilities. Behavioral data gathered over months to years were analyzed graphically for trends in the direction of change. The habitat use dynamics were assessed graphically by looking for trends in the entropy values over time. We found that the activity budgets remained diverse and were dynamic over time, more so in younger compared to older bears. Changes in behavior suggesting positive welfare were observed, while changes that may reflect declining welfare seemed more likely to be due to age or seasonality. The observed behavioral changes suggest that the bears did not become bored with their habitats; there was likely one to several hours of daily variation in behavior, and stereotypy was rare. The diversity in the habitat use decreased over time as the animals settled into patterns of use reflecting preferences for certain areas of their habitats.

Welfare Assessment Tools in Zoos: From Theory to Practice

Zoos are increasingly putting in place formalized animal welfare assessment programs to allow monitoring of welfare over time, as well as to aid in resource prioritization. These programs tend to rely on assessment tools that incorporate resource-based and observational animal- focused measures since it is rarely feasible to obtain measures of physiology in zoo-housed animals. A range of assessment tools are available which commonly have a basis in the Five Domains framework. A comprehensive review of the literature was conducted to bring together recent studies examining welfare assessment methods in zoo animals. A summary of these methods is provided with advantages and limitations of the approach es presented. We then highlight practical considerations with respect to implementation of these tools into practice, for example scoring schemes, weighting of criteria, and innate animal factors for consideration. It is concluded that would be value in standardizing guidelines for development of welfare assessment tools since zoo accreditation bodies rarely prescribe these. There is also a need to develop taxon or species- specific assessment tools to inform welfare management.

BOVIDS: A deep learning-based software for pose estimation to evaluate nightly behavior and its application to Common Elands (Tragelaphus oryx) in zoos

Only a few studies on the nocturnal behavior of African ungulates exist so far, with mostly small sample sizes. For a comprehensive understanding of nocturnal behavior, this database needs to be expanded. Zoo animals offer a good opportunity to lay the corresponding foundations. The results can provide clues for the study of wild animals and furthermore contribute to a better understanding of animal welfare and better husbandry conditions in zoos. To tackle this open question, we developed a stand-alone open-source software based on deep learning techniques, named BOVIDS (Behavioral Observations by Videos and Images using a Deep-Learning Software). This software is used to identify ungulates in their enclosure and to determine crucial behavioral poses on video material with an accuracy of 99.4%. A case study on 25 Common Elands (Tragelaphus oryx) out of 5 EAZA zoos with a total of 11,411 hours video material out of 822 nights is conducted, yielding the first detailed description of the nightly behavior of Common Elands. Our results indicate that age and sex are influencing factors on the nocturnal activity budget, the length of behavioral phases as well as the number of phases per behavioral state during the night. Finally, the results suggest the existence of species-specific rhythms that open future research directions.

Animal-Visitor Interactions and the Visitor Experience: Visitor Behaviors, Attitudes, Perceptions, and Learning in the Modern Zoo

Animal-Visitor Interactions (AVIs) have become commonplace in zoological institutions and facilities globally. However, most AVI research focuses on the effects of visitors on the welfare of animals, with considerably fewer studies examining the visitor experience itself. Furthermore, robust evaluations of the efficacy of zoo education programs and engagements for increasing visitor awareness of conservation issues, and for fostering long-term pro-conservation behavior changes in them, are under-researched. This paper reviews the current literature that pertains to the effects of zoo visitation and AVIs on visitor perceptions, beliefs, and attitudes. We briefly note some of the known effects that zoo visitors have on zoo animals, then explore the effects that factors such as enclosure design, animal visibility and behaviors, and AVIs can have on visitors’ overall experience whilst attending the zoo. We suggest that future research needs to more closely examine the relationships and interactions between zoo visitors and zoo animals; why some zoo visitors over others repeat visitation; what the differences in beliefs and attitudes may be between “zoo visitors” and “non-zoo visitors” (i.e., other general public); and to make a concerted effort to understand: (1) what visitors do after they leave the zoo, and (2) whether visitors adopt long-term pro-conservation behaviors into their daily lives. We further suggest that future research needs to start investigating indirect measures related to the visitor experience, such as: (a) individual conservation support outside of the zoo; (b) internet activity; (c) changes in sustainable purchasing practices related to knowledge gains; (d) financial investment in sustainable or ethical companies after knowledge gains; (e) and the longitudinal effects of zoo visits.