Macropods, particularly kangaroos and wallabies, are common species included in walk-through habitats that put them in close proximity to zoo visitors. However, there has been little research into how visitor presence and density impact the welfare of these individuals. We monitored the behavior and space use of fifteen red kangaroos (Macropus rufus) for a total of ten weeks during and after a nearly three-month zoo closure due to the COVID-19 pandemic. Our findings revealed potential visitor effects, evidenced by more time spent in social proximity, greater inactivity, and more restricted space use after the zoo reopened. Although temperature and weather likely played a role in at least some of these behavioral changes, social proximity and space use changed with crowd size in a manner consistent with our zoo status (i.e., open or closed) results. Additionally, time spent feeding was significantly related to crowd size but not zoo status, such that the kangaroos spent more time feeding when there were no visitors in the habitat. These findings suggest that visitor effects explain these behavioral changes better than seasonal confounds. We also noted several individual differences in response to visitor presence and crowd size, highlighting the importance of evaluating behavioral responses to visitors on an individual basis.

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Western lowland gorillas (Gorilla gorilla gorilla) in zoos are housed in family or bachelor groups to maximize social opportunities. While wild bachelor groups are transient, all‐male groups in zoos may be maintained for many years. Captive bachelor groups need to be carefully monitored, particularly during periods of demographic transition, due to the possibility for escalating aggression. We examined behavioral changes in a bachelor group at the Saint Louis Zoo following two significant alterations in group composition: (1) the introduction of two immature related males in 2011 and (2) the death of the dominant silverback in 2015. Behavioral data were collected on group members using 15 min focal observations with 30‐s instantaneous scans, totaling 185.25 hr for the first transition and 115.25 hr for the second transition (with equal effort in baseline and transition periods). We found that the addition of the two subadult males resulted in a significant increase in affiliation in the group often initiated by these new younger individuals, while the rate of abnormal and aggressive behavior did not change significantly. The rate of abnormal, aggressive, or affiliative behavior in the group also did not change significantly following the death of the dominant silverback. Overall, we conclude that this bachelor group and potentially others can endure possibly destabilizing social transitions and remain cohesive social units. Behavioral changes will result from transitions, but the effect on individuals or impact on the group will vary. Therefore, longitudinal monitoring of bachelor groups will be essential for effective management during any major changes.

Although reptiles are commonly housed in zoos and aquariums, their welfare is understudied for the diversity of species housed and the taxon’s current captive population size. The sensory abilities of reptiles have adapted to the varied ecological niches they inhabit, and these evolutionary adaptations impact how reptiles perceive the stimuli around them—including zoo visitors. This study aimed to assess visitor effects on small groups of six reptile species during a temporary zoo closure due to COVID-19 by measuring behavioral diversity, use of space (measured by a spread of participation index), and select behaviors. The species assessed showed diverse responses. The Catalina Island rattlesnakes (Crotalus catalinensis) demonstrated increased investigation and behavioral diversity after the zoo reopened compared to when the zoo was closed, but the European glass lizards (Pseudopus apodus) showed decreases in the amount of time spent exposed to the observers’ view and in their evenness of space use after the zoo was reopened to visitors. The other species, including beaded lizards (Heloderma horridum), Sonoran spiny-tailed iguana (Ctenosaura macrolopha), Arrau turtles (Podocnemis expansa), and dwarf caimans (Paleosuchus palpebrosus), had intermediate changes in their responses to visitor presence.

Adult males of some primate species are known to positively interact with juveniles. In cases where paternal certainty is high, these behaviors have been largely attributed to the paternal investment hypothesis. Males have also been observed to interact with nonkin juveniles, which has often been explained in terms of mating effort. Here, we examined variation in adult male-juvenile affiliation in semi-free ranging Japanese macaques (<i>Macaca fuscata</i>) at the Oregon National Primate Research Center against possible influencing factors such as age, dominance rank, and female affiliation, and we also tested for fitness benefits. We conducted 154 h of focal observations of 14 adult males from June to September 2018. Males differed significantly in their rate of juvenile-directed affiliation, but not in their fitness in terms of number of offspring. There was a significant positive correlation between rank and age in the group, indicating that, in this group, rank does not conform to the classic inverted-U pattern observed elsewhere in this species. Although there was a significant positive correlation between rank and juvenile-directed affiliation, the highest-ranking male had few offspring and exhibited little juvenile-directed affiliation. These results suggest little to no preliminary support for either the paternal investment or mating effort hypotheses as explanations for juvenile-directed affiliation. This study suggests that there are multiple behavioral strategies for older males that may influence reproductive success.