Search

Here, we evaluated if visual barriers could reduce intraspecific agonism in an all-male group of Nile crocodiles (

Cognitive testing of primates in zoos is becoming increasingly common. Cognition experiments are generally thought to be beneficial as they provide participants with an opportunity to engage in species-specific cognitive functioning, perhaps more so than with traditional forms of environmental enrichment. However, testing may increase competition and aggression between conspecifics if it has monopolizable features or creates social tension within groups. The purpose of this study was to monitor the social behavior of a bachelor mandrill (Mandrillus sphinx) dyad participating in a touchscreen-mediated cognition study. The mandrills' behavior was monitored before and after testing sessions for 8 months. Positive changes in the mandrills' affiliative behavior were observed. Rates of play, presentations, and silent bared-teeth face increased posttesting. No change in rates of agonism were observed between pre- and posttesting conditions. The observed positive changes in affiliative behavior suggest cognitive testing was enriching for the mandrills and participating in testing improved their welfare. Zoos beginning cognitive studies should monitor participant behavior to ensure their welfare is not compromised and is, ideally, enhanced.

Visitor presence has been shown to affect the behavior of animals in zoos. However, studies to date have not included a wide range of taxonomic groupings, and thus, the effect is poorly understood for many species. Here, we compared the behavior of Nile crocodiles (Crocodylus niloticus) in the presence and absence of visitors for the first time. Data were collected at Disney’s Animal Kingdom® over two months during normal operating conditions and during the same two months the following year when the park was closed due to the COVID-19 pandemic, totaling 158 observation hours. Significant differences in crocodile behavior were observed between park operating conditions, however, the direction of change varied by behavior and average differences were generally small. In addition, we found that time of day, temperature and month significantly affected behavior, often with greater magnitude than visitor presence. This highlights the importance of accounting for environmental variables when evaluating and interpreting the behavior, and ultimately welfare, of reptiles in zoos. Collectively, the data suggest the overall effect of visitors on crocodile behavior was small and neutral from a welfare perspective. This study highlights the importance of taxonomic diversity in studying the visitor effect.

The neuroendocrine hormone oxytocin, which is an important physiological driver of social behavior and bonding, is increasingly being measured in conjunction with behavior to better understand primate sociality. To date no data are available on oxytocin concentrations within the genus Gorilla; however, as a result of their close genetic relatedness to humans, and tolerance-based social system, Gorilla represents an important group of study. The purpose of this study was to validate the measurement of urinary and salivary oxytocin in western lowland gorillas (Gorilla gorilla gorilla) to help facilitate future study of the interaction between oxytocin and behavior within the subspecies. The primary validation procedure was an intranasal challenge. Elevated oxytocin concentrations were observed in saliva samples taken 15-120 min post challenge. Urine levels remained within baseline range approximately 30 and 90 min following the challenge; however, elevated levels were observed 24 h post challenge. No diurnal variation was found in salivary samples taken at regular intervals throughout the day; however, morning urine samples had higher concentrations than afternoon samples. In addition, samples were collected opportunistically following three social events: play, breeding, and the death of a conspecific. Following the play bouts, salivary oxytocin was almost three times greater than baseline. Salivary oxytocin was also significantly higher 15 min post breeding compared to match-control samples. Following the death of a conspecific, the group mate's urinary oxytocin concentrations decreased by half compared to a baseline period when the group was intact. This study provides a biological validation of the measurement of urinary and salivary oxytocin in western lowland gorillas. These results suggest that urinary oxytocin measurements are suitable for establishing baseline levels, as they represent the build up of the previous day's concentrations, and salivary oxytocin measurements are suitable for assessing changes following specific events.

In North American zoos, hamadryas baboons (Papio hamadryas) have traditionally been housed as single one-male units (single male groups). In recent years, efforts have been made to house hamadryas in groups composed of multiple one-male units (multi-male groups) to more closely mirror their natural social structure, in addition to all-male or bachelor groups to manage surplus males. Given that the majority of social conflict in hamadryas occurs between males during the acquisition and defense of females, it was thought that managing hamadryas in these multi-male groups would result in increased rates of wounding. To assess this, incidences of wounding were recorded over one year across seven zoos (10 social groups, 59 individuals). Overall, we found no difference in wounding rates between group types, or by sex, and group type. These data provide evidence that managing hamadryas in multi-male and bachelor groups is an effective husbandry practice that does not negatively impact the welfare of the individuals, in addition to providing a more species-appropriate social setting for hamadryas in zoos. As the management of hamadryas in multi-male and bachelor groups continues and expands, additional research will be needed to understand what factors contribute to optimal cohesion, and welfare of groups and if wounding rates change as group size continues to increase.

Conservation education requires a multidisciplinary approach that ideally incorporates iterative monitoring to inform decision making and facilitate achievement of conservation goals. Despite their value and importance, evaluations of conservation education programmes are often challenging to conduct, and are published infrequently. In this study the impact of teacher training on student learning of environmental conservation concepts was assessed in students at 10 schools within 5 km of Kibale National Park, Uganda. Student surveys were administered at the beginning and end of each of 3 school years, throughout which teachers engaged in conservation education training. Results suggest students’ conservation knowledge (e.g. knowing which species live in Kibale National Park, and how students themselves could help conserve wildlife) increased throughout each school year, but there were mixed results regarding the extent to which students showed improved understanding of the environmental problems threatening wildlife, and the reasons underlying the importance of conserving the Park. Understanding student knowledge gains and attitude shifts associated with teacher training in conservation education is important for knowing whether focusing on teachers contributes to intended impacts on student learning. Additional research on outcomes associated with long-term conservation education programmes will be useful for continuing to identify best practices in wildlife conservation.

Positive reinforcement training (PRT) is associated with increases in species-typical behavior and decreases in stereotypic and abnormal behavior in participating animals. Physiological changes following PRT, for example, increases in oxytocin (OXT) and/or decreases in cortisol (CORT), may facilitate these behavioral changes. This study evaluated salivary OXT and salivary CORT concentrations in two adult male western lowland gorillas (Gorilla gorilla gorilla) following PRT with their primary animal care staff. Following PRT, no change in OXT was observed. CORT decreased in one subject following PRT. Changes in endogenous OXT are related to affiliative interactions and interact with strongly bonded conspecifics. PRT may not activate the oxytocinergic system because PRT is not a species-specific affiliative interaction and/or animal care staff are not viewed as conspecifics. Regardless, PRT may still be viewed as a positive interaction resulting in stress reduction via a decrease in CORT. Relationships are unique, thus these results only apply to these two gorillas and one animal caregiver. Larger population-level studies are needed to understand overall trends in human-animal interactions, and ultimately human-animal relationships. Further evaluation of physiological changes following human-animal interactions should be informative for understanding the human-animal relationship in zoos.

Long-term, multi-institutional assessments have become a reliable tool for evaluating patterns of wounding in zoo-living primates, with results informing on best practices for species-specific care protocols and population management strategies. For western lowland gorillas (Gorilla gorilla gorilla) there has been no detailed reports focused on mixed-sex groups, the most common social group type for this species in zoos. In this study, wounding data were collected over 26 months for 131 gorillas living in 26 social groups at 18 zoos and analyzed in relation to age, sex, and group demographic variables. Adult females received wounds at significantly higher rates than adult males suggesting sexual dimorphism and the disparate social roles of male and female gorillas may differentially affect wounding rates. Group size was associated with increased wounding in adult gorillas, however, wounding rates overall were low in frequency and severity. Wound locations were not randomly located, with wounds to the trunk accounting for 24 % of all wounds. These data provide useful insights that may help inform and improve management of gorillas in mixed-sex groups. Specifically, understanding that vulnerability to wounding may be more prevalent in females compared to males can inform strategies aimed at improving husbandry, health, and welfare and have a positive impact on population management practices for the species.

Positive reinforcement training (PRT) has become a widely used tool in improving the ease with which husbandry and veterinary procedures are performed for animals under human care. PRT provides positive social interaction, cognitive stimulation, and choice, in addition to desensitization towards potentially stressful situations. As a result, PRT has been used as enrichment to decrease abnormal and aggressive behavior in various primate species, however, this has not been empirically tested in western lowland gorillas (Gorilla gorilla gorilla). This study used an ABA design to test the effect of PRT on the abnormal and aggressive behavior of an adult female gorilla both during and outside of interaction sessions. No change in behavior was observed during the PRT phase of this study. However, a decrease in ear covering and keeper-directed aggression were observed in the post-training period. Here we argue that the combination of both PRT and non-training interactions cumulatively provided social and cognitive stimuli resulting in the observed changes. These results provide further evidence on the importance of interactions between staff and animals in their care. Further systematic evaluation of the usefulness of PRT as enrichment is still needed, specifically in zoos and across different species. However, PRT is helpful in facilitating husbandry and veterinary procedures and thus should be considered an important tool in optimizing the welfare of animals under human care regardless of its effectiveness as enrichment.

In North American zoos, male gorillas are often housed in all-male (bachelor) groups to provide socialization for males not managed in breeding groups. These groups exhibit long-term cohesion and stability and males in bachelor groups are no more aggressive than males in mixed-sex groups. Previous studies have shown that aggression in male gorillas is more directly related to age rather than group type, with young silverbacks (YSB; males 14–20 years of age) having higher rates of aggressive behavior than males of other age classes. Despite this, anecdotal reports have persisted that bachelor groups have higher wounding rates than mixed-sex groups. To assess wounding in zoo-housed gorillas, all instances of wounding across 28 zoos (180 gorillas, 45 social groups) were recorded over a 26 months period via a standardized data sheet. Similar to previous reports, we found age to be an important determinant in wounding. Bachelor groups that contained YSB's had significantly more wounds than bachelor groups without YSB's (U = 14.0, z = −2.193, P = 0.029). There was no difference in wounding rates between mixed-sex and bachelor groups without YSB's (U = 69.5, z = −0.411, P = 0.689). These data further demonstrate the importance of behavioral management of YSB's in zoos and the viability of bachelor groups as a long-term housing solution for male gorillas. Zoo Biol. 34:296–304, 2015. © 2015 Wiley Periodicals Inc.

Speech act theory describes units of language as acts which function to change the behavior or beliefs of the partner. Therefore, with every utterance an individual seeks a communicative goal that is the underlying motive for the utterance’s production; this is the utterance’s function. Studies of deaf and hearing human children classify utterances into categories of communicative function. This study classified signing chimpanzees’ utterances into the categories used in human studies. The chimpanzees utilized all seven categories of communicative functions and used them in ways that resembled human children. The chimpanzees’ utterances functioned to answer questions, request objects and actions, describe objects and events, make statements about internal states, accomplish tasks such as initiating games, protest interlocutor behavior, and as conversational devices to maintain and initiate conversation.

Films, as part of a larger environmental education program, have the potential to influence the knowledge and attitudes of viewers. However, to date, no evaluations have been published reporting the effectiveness of films, when used within primate range countries as part of a conservation themed program. The Great Ape Education Project was a year-long environmental education program implemented in Uganda for primary school students living adjacent to Kibale National Park (KNP) and Bwindi Impenetrable National Park (BINP). Students viewed a trilogy of conservation films about great apes, produced specifically for this audience, and participated in complementary extra-curricular activities. The knowledge and attitudes of students participating in the program from KNP, but not BINP were assessed using questionnaires prior to (N = 1271) and following (N = 872) the completion of the program. Following the program, students demonstrated a significant increase in their knowledge of threats to great apes and an increase in their knowledge of ways that villagers and students can help conserve great apes. Additionally, student attitudes toward great apes improved following the program. For example, students showed an increase in agreement with liking great apes and viewing them as important to the environment. These data provide evidence that conservation films made specifically to address regional threats and using local actors and settings can positively influence knowledge of and attitudes toward great apes among students living in a primate range country.

In North American zoos, male gorillas are often housed in all-male (bachelor) groups to provide socialization for males not managed in breeding groups. These groups exhibit long-term cohesion and stability and males in bachelor groups are no more aggressive than males in mixed-sex groups. Previous studies have shown that aggression in male gorillas is more directly related to age rather than group type, with young silverbacks (YSB; males 14-20 years of age) having higher rates of aggressive behavior than males of other age classes. Despite this, anecdotal reports have persisted that bachelor groups have higher wounding rates than mixed-sex groups. To assess wounding in zoo-housed gorillas, all instances of wounding across 28 zoos (180 gorillas, 45 social groups) were recorded over a 26 months period via a standardized data sheet. Similar to previous reports, we found age to be an important determinant in wounding. Bachelor groups that contained YSB's had significantly more wounds than bachelor groups without YSB's (U = 14.0, z = -2.193, P = 0.029). There was no difference in wounding rates between mixed-sex and bachelor groups without YSB's (U = 69.5, z = -0.411, P = 0.689). These data further demonstrate the importance of behavioral management of YSB's in zoos and the viability of bachelor groups as a long-term housing solution for male gorillas.