A preliminary global investigation into potential impacts on successful captive breeding for two species of Rhyticeros hornbill.

Asian hornbills have limited ex situ breeding success, yet these species are some of the most threatened of birds, in need of managed breeding programs. To optimize breeding and increase the sustainability of such populations, it is necessary to assess and improve their husbandry and welfare. Evidence to improve reproduction can be gathered through global husbandry surveys. A survey was sent out to all European Association of Zoos and Aquaria and Association of Zoos and Aquarium holders of the wreathed hornbill (Rhyticeros undulatus) and Papuan hornbill (R. plicatus) to determine predictors for ex situ breeding success. This research found that pairs that have spent more years together (p = .016) and that adding additional proteins to the diet (p = .006) are two significant predictors of breeding success for wreathed- and Papuan hornbill pairs. This paper found a general trend that successful hornbill pairs prefer nest boxes that are situated outside (p = .054). The behaviors of calling to each other and sitting in close proximity showed a general trend and were observed more frequently in successful pairs and, therefore, could be good indicators of bonded pairs. We recommend that ex situ institutions allow their hornbill pairs time to form strong bonds, and that pair compatibility is monitored regularly to ensure that such interactions are positive and not consistently negative. An increase in the percentage of dietary proteins, prior and during the breeding season appears to stimulate pairs to breed. If the management and husbandry alterations presented in this study are implemented, the sustainability of Rhyticeros hornbill populations may be enhanced.

What is the role of the studbook in zoo and aquarium research?

In zoos and aquariums globally, studbooks provide a format by which threatened or important species populations can be carefully managed. These documents can be used to answer complex questions about animal population demographics, animal husbandry, breeding success and mortality. Given the time-intensive nature of studbook collation, only a subset of all animal species held in zoological facilities are managed using these programs. The purpose of this project was to identify how studbooks are being used by researchers, the topics being investigated, and the taxa being covered. To achieve this, data were collected on the types of research paper being produced using studbook information. A literature search, covering several zoo and aquarium journals, was utilized. Data on the types of studbook available were additionally collected for three international zoo organizations. A Poisson regression was run to determine the predictive power of taxonomic class, animal threat status and studbook type on a studbook featuring in published research. Overall, the study identified that taxonomic class and threat status were significant predictors of the number of published studbook papers, with threatened species being more likely to appear in papers. Additionally, population demography was the most common use of studbook data, followed by genetics and reproduction. Not all taxonomic groups were featured in the literature, with mammals featuring much more frequently than would be expected based on the types of studbook available.

Never be mute about bird welfare: Swanning around with environmental enrichment.

Environmental enrichment (EE) is commonly provided to animals managed under human care, being beneficial to behavioral diversity and improving animal welfare. Use of EE appears to be particularly beneficial to individual wild animals spending a short period of time in captivity, for example, as part of conservation or rehabilitation programs. This paper documents a case study on the application and relevance of EE for a group of captive mute swans housed in a rescue center. Observational data were analyzed for two groups of juvenile swans that were provided with a physical EE device to increase time spent foraging. Periods of no EE were observed and compared to data from when birds were provided with EE. Results show that EE promoted foraging time and helped to reduce long periods of inactivity in captive birds. EE helped to reduce occurrence of captive-focused (i.e., abnormal behaviors) although these was already seen at very low rates. Inactivity as a measure of welfare in captive swans specifically (and waterbirds generally) should be further investigated to understand potential impacts on bird health. Our research shows the benefits of simple and easy-to-use EE devices on captive animal behavior and how use of EE for individuals spending a short amount of time in captivity (e.g., within a rescue center) could ensure diversity of behavior patterns and promote the performance of adaptive behaviors upon release to the wild.

The Zone Overlap Index: A new measure of shared resource use in the zoo.

It is important that the environment provided in the zoo is relevant to the species being housed and its suitability be easily assessed by personnel. As shared space and resources can overlap in a zoo's enclosure a tool is required to measure the effects of such overlap between individual animals in a shared enclosure. This paper outlines the Pianka Index (PI), a tool used in ecology to quantify niche overlap, that has value in quantifying the amount of time that animals spend in shared enclosure zones. One limitation to this method, however, is that the established method of determining the PI requires division of the enclosure into equally sized zones, something that is not always relevant to a zoo enclosure. To combat this, we created a modified index, entitled the Zone Overlap Index (ZOI). This modified index is the exact mathematical equivalent of the original index when zone sizes are equal. When zone sizes are unequal, the ZOI generates higher values when animals share smaller, as opposed to larger, zones. This is because animals are more likely to share larger enclosure zones simply by chance, and shared use of smaller zones brings individuals into closer proximity with the potential for competition. To illustrate the application of the ZOI, a series of hypothetical situations were generated to reflect real-world scenarios, demonstrating how this index could be used to better understand zone occupancy overlap in the zoo.

Exploration of Social Proximity and Behavior in Captive Malayan Tigers and Their Cubs.

The survival of endangered felids is becoming increasingly dependent on the successful management and breeding of reserve populations in captivity. While most felid species are reported to be solitary in the wild, increasing evidence suggests that some big cats have greater social plasticity than is currently acknowledged. This social plasticity allows felids to be sometimes socially housed in environments such as zoos and rescue centers. While the effects of such shared enclosures remain in question, many reports provide evidence of several welfare benefits of maintaining these large carnivores in pairs or even groups. Since 2019, Le Parc des Félins has housed a breeding pair of Malaysian tigers (Panthera tigris jacksoni) alongside their offspring. The purpose of this study was to quantify the social affiliation between the male tiger and his cubs and to investigate the female's tolerance toward him. The data were collected using video recordings in the outdoor enclosure when social interactions were observed. The data were coded and categorized in the open-source software BORIS, from which behavioral activity budgets were calculated. Data were analyzed using the chi-squared test for association to determine differences in affiliative frequency, with directed and undirected sociograms created to visualize individual relationships. Overall, the male regularly engaged in affiliative behaviors with the cubs, with no significant difference found in the frequency of interactions with them compared to the female. No physical aggression was directed by the male toward the cubs. Although the female maintained a stronger bond with the cubs compared to the male, he displayed a greater range of affiliative behaviors toward them than male tigers are thought to exhibit. Both adults showed a high degree of tolerance toward their conspecifics, suggesting that maintaining breeding pairs with their offspring is a viable management strategy in zoological collections. This study could therefore improve husbandry and conservation practices by developing our understanding of felid sociality and the potential welfare benefits of social housing, allowing for evidence-based captive management decisions.

Visitors and observers otter-ly influence the behavior and enclosure use of zoo-housed giant otters.

The potential impact of human presence on captive animal behavior has recently been the focus of considerable research interest, especially following 2020 and 2021 periods of enforced closure as a result of COVID-19 opening restrictions. It is important to investigate whether human presence represents an enriching or stressful stimulus to a range of zoo-housed species. In 2020, during an easing of lockdown restrictions, investigations of the "visitor effect" and "observer effect" were carried out, using the giant otter (Pteronura brasiliensis) as a model species. To investigate the impact of both visitor and observer presence, otter behavior and space use was recorded for a pair of on-show and a pair of off-show otters. Observations were conducted using either a human observer, or cameras, allowing the researchers to investigate otter behavior when no one was present at the exhibits. The Electivity Index was used to assess the otters' use of four enclosure zones. Overall, otter behavior was significantly impacted by observer presence, though the impact of an observer differed between individual otters. Visitors had a minimal effect on otter enclosure use, whereas observers had a greater impact, whereby otters used their pools less frequently and houses more frequently when observers were present. However, this change in zone use differed between individuals, with more dominant otters tending to make use of indoor zones more often when observers were present. Zoos should consider the potential impact of human presence on their animals and use both behavior and space use when conducting their investigations.

Investigating Unused Tools for the Animal Behavioral Diversity Toolkit.

Behavioral diversity is a commonly used tool used to quantify the richness and evenness of animal behaviors and assess the effect of variables that may impact an animal's quality of life. The indices used in behavioral diversity research, and the study subjects, have not been formally reviewed. This paper aims to identify which indices are being used in behavioral diversity research, and under which scenarios, and uncover novel indices from other disciplines that could be applied to behavioral diversity. To investigate the techniques and species investigated in behavioral diversity literature, a Web of Science literature search was conducted. Two methods: behavioral richness and the Shannon-Wiener index, were the most frequently used indices, whereas the Behavioral Variability index featured rarely. While a range of species appeared in the behavioral literature, mammals were the most frequently studied Class, whereas amphibians did not feature in any papers. There are several diversity indices which did not feature in behavioral diversity including Simpson's index, and Chao. Such indices could be used to better understand animal behavioral study outputs or be used to estimate the number of 'unobserved' behaviors that an animal may express. Future studies could therefore extend beyond the Shannon-Wiener and richness indices.

Investigating the Behavior and Personality Structure of the Aldabra Tortoise during Human Interactions and Training Events.

Human-animal interaction (HAI) can be valuable for captive animals, and many zoo-housed species benefit from interactions with their keepers. There is also an increasing body of evidence that some animal species possess personalities that are temporally consistent. However, the majority of zoo research, particularly on personality and HAI, traditionally has focused on mammals, and there are comparatively fewer studies on reptiles. Research was undertaken at the Faunistic Park Le Cornelle, Italy, to investigate the effects of approach tests and food interaction events on 5 male and 5 female Aldabra tortoise (Aldrabrachelys gigantea) behavior. During human-tortoise interactions, continuous focal sampling of behavior took place. The behavioral differences between individual tortoises, interaction type (approach or training) and person involved in the interaction (keeper, vet, or observer) were analysed using general linear mixed-effects models. The personality components of the tortoises were also quantified using principal component analysis. Overall, the study revealed that individuals acted significantly differently to one another, and that while females initially appeared to display a greater number of shy behaviors, this was not consistent across the group. PCA revealed two personality dimensions in the tortoises: boldness and avoidance. Overall, the study revealed that the tortoises possessed personalities that were independent of sex or scenario. The study also revealed that many tortoises chose to interact with their keepers during training and approach tests: this suggests that human-tortoise interactions may have some enrichment value. Future research could quantify tortoise personality in other scenarios such as in social interactions with other tortoises.

A simulated comparison of behavioural observation sampling methods.

Behavioural research requires the use of sampling methods to document the occurrence of responses observed. Sampling/recording methods include ad libitum, continuous, pinpoint (instantaneous), and one-zero (interval) sampling. Researchers have questioned the utility of each sampling method under different contexts. Our study compared computerized simulations of both pinpoint and one-zero sampling to continuous recordings. Two separate computer simulations were generated, one for response frequency and one for response duration, with three different response frequencies (high, medium, or low) and response durations (short, medium, and long) in each simulation, respectively. Similarly, three different observation intervals (5, 50, and 500 s) were used to record responses as both pinpoint and one-zero sampling methods in the simulations. Under both simulations, pinpoint sampling outperformed one-zero sampling, with pinpoint sampling producing less statistical bias in error rates under all frequencies, durations, and observation intervals. As observation intervals increased, both mean error rates and variability in error rates increased for one-zero sampling, while only variability in error rate increased for pinpoint sampling. The results suggest that pinpoint sampling techniques are effective for measuring both frequency (event) and duration (state) behaviours, and that pinpoint sampling is a less statistically biased behavioural observation method than one-zero sampling.

Understanding sociality and behavior change associated with a nesting event in a captive flock of great white pelicans.

Zoo-housed pelicans are commonplace, but their breeding record is poor and little research is published on the activity patterns, as potential predictors of nesting, of captive flocks. Existing literature shows that comparative research can provide useful information for husbandry and conservation planning for pelican populations. The opportunity arose to investigate the time-activity budget and social network of a breeding flock of captive great white pelicans. Three chicks were hatched in June and July 2016 and one in March 2017. Data on state behaviors, space use, and association preferences were collected around these nesting events, from October 2016 to February 2017 and July to October 2017. Results suggest that pre-nesting periods were associated with heightened flock-wide vigilance, suggesting that vigilance may be a precursor for courtship or nesting activity. Social network analysis revealed nonrandom associations between birds and a social structure across the flock, in which subadults seemed to associate more with each other than with adult birds. A limited visitor effect was noted; whilst no overall behavior change was apparent with different numbers of visitors, pelicans did widen their enclosure usage with increased visitor presence. These data are relevant to those attempting to breed this pelican, who wish to know more about the daily behavior patterns of this species across the season and physiological state, and who wish to understand pelican social structure, which is useful to the planning and implementation of bird moves or changes to the social environment of the flock. Further extending such research to include uninterrupted observation over a successful breeding event is recommended.

Why the "Visitor Effect" Is Complicated. Unraveling Individual Animal, Visitor Number, and Climatic Influences on Behavior, Space Use and Interactions With Keepers-A Case Study on Captive Hornbills.

A "visitor effect" on zoo-housed species has been documented since the 1970s, with research focused on mammals (specifically primates). To broaden our understanding of the "visitor effect" in a non-mammal, we conducted a case study on a pair of hornbills, recording behavior and aviary use alongside of visitor and keeper presence. Temperature and humidity were significant predictors of visitor number, and temperature was a better predictor of hornbill exhibit use than visitor presence. Behavior was significantly affected by the presence of keepers and individual variation in behavior was noted too. Visitor number mediated any interest in a keeper by birds: high visitor number decreased a bird's interest in its keeper. Whilst only a case study on a pair of birds, our research shows that any "visitor effect" is heavily influenced by other environmental variables and that different categories of human (i.e., visitor, keeper) affect how zoo animals utilize their environment.

Patterns of nocturnal activity in captive greater flamingos.

Wild flamingos are known to forage overnight, but little is known of their nocturnal activity patterns in captivity. Captive flamingos can show daytime inactivity, reflecting natural periods of resting and loafing documented in wild birds. Assessment of behavior outside of normal zoo opening hours can provide more detailed information on how animals use the space provided to them, and highlights how enclosure areas not commonly occupied during the day may still be important for inhabitants at other times. We examine whether captive flamingos at WWT Slimbridge Wetland Centre change their enclosure usage and behavior overnight compared to that observed during daylight. Using three night-vision remote cameras, the behavior and enclosure usage of a flock of over 270 greater flamingos was recorded from March to July 2016. Results show that these flamingos had higher rates of foraging at certain points during the night, and had a more even enclosure usage when compared to daylight hours. Change in pool use is apparent throughout the course of the day and night, suggesting that different areas of water depth are used by these flamingos at different times. Flamingos increased nocturnal foraging in their pool during the breeding season. The large enclosure size and range of different land and water areas may have enabled these flamingos to follow daily activity patterns similar to those observed in wild birds. Captive flamingos clearly show a difference between daytime and nocturnal behavior patterns and this should be considered when designing enclosures and general management routines for these birds.