Effect of feeding boxes on the behavior of stereotyping amur tigers (Panthera tigris altaica) in the Zurich Zoo, Zurich, Switzerland

Breaking the spell: Changes in the behavior of two zoo-kept tigers (Panthera tigris) after exposure to a distinct feast-and-fast feeding regime

The behavior of zoo carnivores has received intense attention due to their propensity for locomotor stereotypies. We observed two adult male tiger (Panthera tigris) siblings kept together for the duration of 104 days by round-the-clock video observation. The period consisted of three baseline periods with the zoo's regular feeding regime of five feeding days per week interrupted by two individual fasting days, with feeding occurring in the evening (B1-B3 of 14 days each). These periods were interrupted by two intervention periods (I1: randomized feeding times, 28 days; I2: gorge-feeding with three 10-day fasting periods, 34 days). As expected, day and night-time behavior was different, with the majority of sleep occurring at night. Pacing, which was mainly considered anticipatory, significantly decreased from 88 ± 132 min/day during B1 to 20 ± 33 min/day during B3. Pacing did not increase during the fasting days of I2. Over the course of whole study, lying time decreased and nonpacing locomotion increased. A major difference was observed between gorge-feeding and the subsequent first fasting days: during gorge-feeding, tigers spent a large part of the day feeding and locomoting (and less sleeping); on the subsequent day, they locomoted about 4.5 h less and slept about 4.3 h more. We suggest that interrupting routines by fasting periods of several days may be effective for reducing regular anticipatory behavior and creates an across-day structure that may correspond to the evolved psychological disposition of large carnivores.

Health and Welfare Benefits of Computerized Cognitive Enrichment in California Sea Lions (Zalophus californianus) at the US Navy Marine Mammal Program

Cognitive enrichment is becoming more prevalent in professional marine mammal facilities. Research with dolphins has suggested that such enrichment provides more welfare benefits than enrichment that does not incorporate cognitive challenge. However, there is little research supporting the use of cognitive enrichment as a means to improve the welfare of sea lions. Recently, a novel form of technological cognitive enrichment, the Enclosure Video Enrichment (EVE) system, was introduced to a population of California sea lions at the US Navy's Marine Mammal Program as a means to enhance welfare. Two of the initial focal animals introduced to EVE were selected based on their health history and the possible benefits of cognitive enrichment in improving health measures. To evaluate this, information regarding the animals' consumption of their offered diet was compared to other animals in the population of similar age and the absence of a similar health history. Subsequently, the total diet consumption of the targeted animals was evaluated in the two years prior to the introduction to EVE and compared to the total diet consumption during the initial 2 years of regular EVE sessions. There was a significant decrease in the number of days in which the sea lions did not consume their entire offered diet in the two years after implementing regular EVE sessions, an increase in participation and performance of voluntary husbandry behaviors, and a reduction in the number of days animals were clinically ill. This study provides evidence of cognitive enrichment as a management tool to improve animal health and welfare as well as performance in training sessions.

Using Anticipatory Behavior to Detect the Change in Interest in an Activity Repeated Several Times and Avoid Habituation in Bottlenose Dolphins (Tursiops Truncatus)

Environmental enrichment is an essential component of the management policies used by zoos and aquaria to promote animals' welfare. However, when enrichments are provided several times, they can cause habituation and lose their enrichment effects. A simple method to avoid it could be making a preventive assessment about the trend of animals' interest in a stimulus provided several times. Here, we hypothesized that anticipatory behavior could be used to assess the decrease in interest in playing with objects when the activity is repeated. Moreover, we also assumed that this could be done before providing objects to play with. Our results support this hypothesis. Specifically, we found a positive correlation between the time the 7 dolphins tested spent performing anticipatory behavior before the enrichment sessions and the time they spent playing with objects during those sessions. As a result, anticipatory behavior performed before enrichment sessions predicted dolphins' interest in the session and allowed us to assess whether the sessions had lost their enrichment effect.

Case study: Visual barriers reduce pacing in captive tigers

Captive large felines are prone to abnormal repetitive behaviors like pacing, which are associated with welfare issues. Visual contact without the opportunity to engage in appropriate behavior is known to increase pacing. To better understand the relationship between pacing and conspecific visual contact, we investigated this effect by conducting a barrier experiment on a male-female pair of Sumatran tigers (Panthera tigris sumatrae) in Rotterdam Zoo, the Netherlands. The tigers were exposed to four consecutive housing treatments: (i) housed in the same enclosure (baseline), (ii) housed in separate enclosures with visual contact, (iii) housed in separate enclosures without visual contact, and (iv) housed in the same enclosure after the separation. We used focal and scan sampling to measure pacing and recorded the number of visitors. Moreover, we applied scan sampling to measure activity. Overall, our results indicate that the tigers paced significantly more when housed in separate enclosures with conspecific visual contact. Moreover, our results suggest that limiting visual contact between neighboring tigers can mitigate pacing. Implementing these findings in tiger husbandry and enclosure design has the potential to improve animal welfare zoo populations of large felines.

The influence of feeding routines on the behavior of zoo-housed Sulawesi crested black macaques (Macaca nigra)

Many species thrive in captivity, yet there is still much to be assessed regarding the often-unknown stressors present that can compromise welfare. Uncovering such stressors is of paramount importance if we are to ensure the zoo environment provides the highest levels of animal welfare that will contribute to species conservation. Zoo-housed primates are subject to many potential stressors, including daily husbandry routines which they may find aversive or habituate to, regardless of their outcome. The specific aim of this study was to assess the behavioral responses to daily husbandry feeding routines on a total of 33 Sulawesi crested black macaques (Macaca nigra), across two different UK zoological collections. Group scan sampling was used to record behaviors for 30-min periods before feeding (BF), for 30 min after feeding (AF), which we began 30 min after feed provision, and for 30 min when no feeding occurred (NF). The feeding condition significantly influenced behaviors recorded and post-hoc comparisons showed that BF conditions produced significantly higher frequencies of food anticipatory related activity (FAA). Furthermore, during BF periods, behaviors associated with FAA increased during the 15 min closer to a feed. This research finds that temporal feeding events cause changes in the behavior of two independent groups of crested macaques, indicative of food anticipation activity, during 30-min periods leading up to a feed. These results have implications for how animal keeper routines and advertised zoo feeds are managed for this species within zoological collections.

Effects of Complex Feeding Enrichment on the Behavior of Captive Malayan Sun Bears (Helarctos malayanus)

All zoos grapple with challenges of keeping captive animals engaged in natural behaviors, especially for bears which prove to be among the more challenging species to keep stimulated. In captivity, a common indicator of poor welfare is the presence of stereotypic behaviors. This study tests whether providing complex feeding enrichment devices decreases the duration of stereotypic behavior and increases enrichment interaction for three adult female sun bears (Helarctos malayanus) at Oakland Zoo in California. This study uses two different enrichment devices presented at three complexity levels. After three weeks of baseline data collection when no complex enrichment is present, the complex enrichment is introduced three times a week per level over six weeks. Sun bear interaction with the enrichment devices is also measured to examine the effect of complexity on enrichment use. Providing complex enrichment decreased the duration of stereotypic behavior when compared to baseline. Across the six weeks, the duration of stereotypic behavior is significantly less on the complex enrichment days compared to non-complex enrichment days. The complex enrichment has variable effects on enrichment use. These results suggest that providing complex enrichment may have a positive influence on the behavior of captive bears.

The Effects of Choice-Based Design and Management on the Behavior and Space Use of Zoo-Housed Amur Tigers (Panthera tigris altaica)

Choice-based design allows animals in human care opportunities to move at will between multiple interconnected spaces. Some evidence suggests providing environmental choice confers benefits to animals, but there is a dearth of research in this area with large carnivores. To understand the effects of this design strategy on large felids, behavioral and space use data were collected on three Amur tigers housed in a new habitat at Cleveland Metroparks Zoo. Data were collected in two conditions: 1) restricted to a single habitat, and 2) access to two habitats. With choice, tigers were less frequently inactive (p = 0.003), and locomoted more frequently (p = 0.009). They also showed different preferences in space use with choice, and a strong preference for overhead runways between habitats (E* = 0.83, E* = 0.78). These results add to what is known about environmental impacts on zoo animal behavior and suggest this design and management strategy may be effective in conferring positive welfare benefits to tigers and other large carnivores.

Environmental Enrichment Factors Associated with the Activity Level of Bottlenose Dolphins under Professional Care

Environmental enrichment can be used to improve the welfare of dolphins in zoos and aquariums. Bottlenose dolphins under professional care are typically provided with a range of enrichment that has a variety of features and levels of complexity at various frequencies. In the present study, a subset of data from a larger study entitled “Towards understanding the welfare of cetaceans in zoos and aquariums” (colloquially called the Cetacean Welfare Study) was used to examine the relationship between activity level and enrichment buoyancy as well as enrichment provisioning schedules. Survey data were collected from accredited zoos and aquariums related to the types of enrichment provided to the dolphins and the frequency and duration they were supplied. Non-invasive bio-logging devices were used to record the dolphin kinematics one day per week over the course of two five-week data collection periods. Activity level related positively with the total duration of time non-stationary enrichment was provided. In addition, providing a larger number of enrichment types each between 26% and 50% of the days in a month (i.e., rotating many different types of enrichment across days on a moderate schedule) was positively related to activity level. Activity level was negatively related to the number of times sinking enrichment was provided. Understanding how the temporal schedule and features of various types of enrichment are related to activity levels will aid in developing progressively more effective enrichment programs.

Making a Tiger's Day: Free-Operant Assessment and Environmental Enrichment to Improve the Daily Lives of Captive Bengal Tigers (Panthera tigris tigris)

There are more captive tigers in the United States than there are wild tigers in the entire world. Many animals under human care engage in problem behaviors such as excessive grooming and aggression, although the origin of these behaviors is typically unknown. Environmental enrichment may mitigate these issues in captive animals of all kinds. In order to individualize enrichment experiences, the current study used a free-operant assessment procedure to establish a menu of most preferred play items and scents among 7 Bengal tigers (Panthera tigris tigris) housed at a sanctuary in southwest Missouri. Each tiger was tested 3 times with scents (cinnamon and Calvin Klein Obsession perfume) and play items (boxes, balls, leaves, and pumpkins). The importance of rigorous assessment of presumed reinforcers among captive wild animals, as well as the difficulty of effectively assessing tigers while ensuring the safety of both the participants and researchers, is discussed.

Influence of vitamin E and carcass feeding supplementation on fecal glucocorticoid and androgen metabolites in male black-footed ferrets (Mustela nigripes)

In recent years, the ex situ population of the endangered black-footed ferret (Mustela nigripes; ferret) has experienced a decline in normal sperm morphology (from 50% to 20%), which may be linked to inbreeding depression and/or a dietary change. We examined the effects of adding carcass and vitamin E to the diet on stress and reproductive biomarkers in male ferrets (n = 42 males including 16 juveniles and 26 adults) housed at the U.S. Fish and Wildlife National Black-footed Ferret Conservation Center (Carr, CO, USA). Fecal samples (3x/week) were collected from November and December (pre-breeding season, no diet change), February through May (breeding season, diet change) and June (post-breeding season, diet change) and analyzed for fecal glucocorticoid metabolites (FGM) via a corticosterone enzyme immunoassay (EIA). A subset of samples from adult males (n = 15) were analyzed for fecal androgen metabolites (FAM) via a testosterone EIA. We first used a linear mixed effects model to identify the important fixed effects among meat treatment, vitamin E treatment, age class (juvenile or adult), and all possible interactions on each hormone. We then examined the important factor’s effects across seasons using the non-parametric Friedman test. We found that age did not influence (p = 0.33) FGMs; however there was a significant effect of meat treatment on FGM (p = 0.04) and an effect of vitamin E on FAMs (p<0.10). When fed carcass, FGMs declined (p<0.001) from pre- to the during the breeding season time period, but was similar (p>0.05) between during and post-breeding season periods. Males that were not fed carcass had higher (p<0.05) FGMs during the breeding season compared to pre- and post-breeding season and FGMs were lower (p<0.05) in the post-breeding season compared to pre-breeding season. Males fed with carcass had lower (p<0.001) FGM than males that were not fed carcass during both the pre-breeding and the breeding season but not during the post-breeding season (p>0.05). Males supplemented with vitamin E had higher (p<0.001) FAM than non-supplemented males during the breeding season only. For both groups, FAM was highest (p<0.05) during the breeding season. In conclusion, adding carcass to the diet can reduce glucocorticoid production and adding vitamin E can increase testosterone during the breeding season, which may influence reproductive success.

Can Zoos Ever Be Big Enough for Large Wild Animals? A Review Using an Expert Panel Assessment of the Psychological Priorities of the Amur Tiger (Panthera tigris altaica) as a Model Species

Simple Summary

The reduction in space available to wild animals in zoos and aquariums is widely perceived to be detrimental to their welfare by scientists and the general public alike. Evidence suggests that naturally wide-ranging carnivores are more likely to suffer in captivity than those that travel less widely. Using the Amur tiger as a representative for wide-ranging species frequently held in zoos, an expert panel assessment was undertaken to identify psychological priorities in order to see how the negative welfare impacts of reduced ranging opportunities might be most effectively overcome. This assessment highlights that whilst reduced access to space may be central to compromised welfare for many species, there may be more effective strategies in safeguarding welfare than simply making captive habitats marginally bigger. Central to this for Amur tigers is providing appropriate mental stimulation rather than focusing only on behaviours linked to hunting. Various strategies intended to safeguard welfare are discussed for Amur tigers, which can also be considered for other wide-ranging species.

Abstract

The ecology of large, wide-ranging carnivores appears to make them vulnerable to conservation challenges in the wild and welfare challenges in captivity. This poses an ethical dilemma for the zoo community and supports the case that there is a need to reconsider prevailing management paradigms for these species in captivity. Whilst the welfare challenges wide ranging carnivores face have been attributed to reduced ranging opportunities associated with the decreased size of captive habitats, attempts to augment wild carnivore welfare in captivity typically focus on behaviours linked to hunting. Thus far, this has yet to result in the systematic elimination of signs of compromised welfare amongst captive carnivores. Here an assessment is carried out to identify the likely welfare priorities for Amur tigers, which, as one of the widest ranging terrestrial carnivores, serves as an excellent exemplar for species experiencing extreme compression of their ranging opportunities in captivity. These priorities are then used to consider novel strategies to address the welfare challenges associated with existing management paradigms, and in particular, attempt to overcome the issue of restricted space. The insights generated here have wider implications for other species experiencing substantive habitat compression in captivity. It is proposed here that the impact of habitat compression on captive carnivore welfare may not be a consequence of the reduction in habitat size per se, but rather the reduction in cognitive opportunities that likely covary with size, and that this should inform strategies to augment welfare.

Effect of Bungee-carcass enrichment on behavior and fecal glucocorticoid metabolites in two species of zoo-housed Felids

Enrichment can improve animal physiological and psychological well-being. This study sought to promote more natural felid behavior and prevent development or incidence of stereotypies through the use of a feeding enrichment. Our objectives are to use fecal glucocorticoid metabolites values and behavioral observations to quantify the effectiveness of the enrichment device for two species of large cats, Bengal tiger (Panthera tigris tigris; n = 2) and cougar (Felis concolor; n = 2). The feeding enrichment, a white-tailed deer carcass flank securely attached to an AussieDog Products(©) Felid 120-cm bungee, was implemented twice for each individual separated by 1 month. Fecal samples were obtained from each felid and analyzed for pre- and post-enrichment fecal glucocorticoid metabolites (FGM) concentrations using a cortisol enzyme immunoassay. An ethogram with 12 mutual exclusive behavioral categories was utilized to record behavioral responses to the enrichment. Results demonstrate that: 1) there were no differences (P > 0.05) in FGMs for either species between pre- and post-enrichment; 2) pacing decreased (P = 0.025) and walking increased (P = 0.017) after exposure to enrichment in both cougars; and 3) tigers reduced (P = 0.025) 'other' behavioral category after the first enrichment exposure and laid down more (P = 0.025) after the second enrichment exposure. The neutral hormonal impact on the animals coupled with the behavioral changes indicates that this enrichment is successful at altering the animals' behavior without adding physiological stress to their environments. These findings, combined with the low cost and versatility of the enrichment, promote the use of this enrichment to enhance large felid enclosures.

Behavioral and physiological responses in felids to exhibit construction

Despite the growing body of literature examining the welfare of zoo-housed animals, little standardized work has been published on the effect of construction and environmental disruption on the physiology and behavior of affected animals. When Lincoln Park Zoo (Chicago, IL), embarked on a renovation project for its Kovler Lion House, the opportunity was taken to perform a scientific study of behavioral and physiological markers in the resident felids to determine the effect of construction and environmental disruption. Fecal samples and behavioral observations were collected on four felid species (five individuals) before, during, and after the period of construction. As a group, the average z-score for fecal glucocorticoid metabolite concentration increased during construction relative to baseline. Levels remained elevated after construction, but trended toward baseline. All individuals demonstrated a significant decrease in the frequency of pacing and time spent visible during construction. Overall activity levels also showed a significant decrease relative to baseline measures. As zoological institutions continue to recognize the importance of habitat design, construction and renovation become inevitable. It is important to be aware of the potential consequences this can have on animals in the vicinity and to work toward minimizing negative effects. One recommendation is the availability of ample retreat and hiding space for felids during disruption to their environment.

The Effects of Predictability in Daily Husbandry Routines on Captive Rhesus Macaques (Macaca mulatta)

Rhesus macaques (Macaca mulatta) housed indoors experience many routine husbandry activities on a daily basis. The anticipation of these events can lead to stress, regardless of whether the events themselves are positive or aversive in nature. The specific goal of this study was to identify whether increasing the predictability of husbandry events could decrease stress and anxiety in captive rhesus macaques. This study was conducted on 39 single-housed subjects in four indoor rooms at the Oregon National Primate Research Center. Temporal and signaled predictability were added to four daily husbandry events: morning and afternoon feeding, enrichment distribution, and room cleaning. Temporally predictable husbandry events occurred reliably at the same time daily, while signaled predictable husbandry events were preceded by a distinct event-specific signal in the form of a doorbell. Informal tests prior to study onset found the doorbells not to be aversive to the subjects. Subjects received each of four treatments: unpredictable events, temporally predictable events, signaled predictable events, and temporally and signaled predictable events. Change in stress was evaluated by monitoring changes in motor stereotypies and displacement behaviors. Our results showed that subjects displayed less stress and anticipatory behaviors related to feeding and enrichment events when the events were temporally predictable (P < 0 .0001). When husbandry events were preceded by a reliable signal, subjects vocalized less prior to the event and were less responsive to activity outside of the room (P < 0 .01). However this may have come at a cost as the animals were extremely reactive to the doorbell signals and showed a heightened stress response during the actual husbandry events (P < 0 .01). Similar to temporal predictability alone, when temporal predictability was combined with signaled predictability subjects displayed less stress and anticipatory behaviors related to feeding and enrichment events (P < 0 .0001). In addition, when both forms of predictability were combined subjects showed less stress behaviors while waiting for daily room cleaning (P < 0 .01). When signaled predictability was paired with temporal predictability subjects no longer had the negative response to the doorbell signal, as they were able to predict and anticipate when the events would occur. Because these results are not necessarily applicable to animals that are given control over their environment or housed in a group setting, the management recommendation that can be made from this study is that temporal predictability of feeding reduces stress and anxiety and is thus beneficial to captive indoor single-housed rhesus macaques.

Environmental enrichment for a mixed-species nocturnal mammal exhibit

Environmental enrichment (EE) is an integral aspect of modern zoo animal management but, empirical evaluation of it is biased toward species housed in single-species groups. Nocturnal houses, where several nocturnal species are housed together, are particularly overlooked. This study investigated whether three species (nine-banded armadillos, Dasypus novemcinctus; Senegal bush babies, Galago senegalensis; two-toed sloths, Choloepus didactylus) in the nocturnal house at Paignton Zoo Environmental Park, UK could be enriched using food-based and sensory EE. Subjects were an adult male and female of each species. EE was deemed effective if it promoted target species-typical behaviors, behavioral diversity, and increased use of enriched exhibit zones. Results from generalized linear mixed models demonstrated that food-based EE elicited the most positive behavioral effects across species. One set of food-based EEs (Kong®, termite mound and hanging food) presented together was associated with a significant increase in species-typical behaviors, increased behavioral diversity, and increased use of enriched exhibit zones in armadillos and bush babies. Although one type of sensory EE (scented pine cones) increased overall exhibit use in all species, the other (rainforest sounds) was linked to a significant decrease in species-typical behavior in bush babies and sloths. There were no intra or interspecies conflicts over EE, and commensalism occurred between armadillos and bush babies. Our data demonstrate that simple food-based and sensory EE can promote positive behavioral changes in a mixed-species nocturnal mammal exhibit. We suggest that both food and sensory EE presented concurrently will maximize opportunities for naturalistic activity in all species.

Contrafreeloading in grizzly bears: implications for captive foraging enrichment

Although traditional feeding regimens for captive animals were focused on meeting physiological needs to assure good health, more recently emphasis has also been placed on non-nutritive aspects of feeding. The provision of foraging materials to diversify feeding behavior is a common practice in zoos but selective consumption of foraging enrichment items over more balanced "chow" diets could lead to nutrient imbalance. One alternative is to provide balanced diets in a contrafreeloading paradigm. Contrafreeloading occurs when animals choose resources that require effort to exploit when identical resources are freely available. To investigate contrafreeloading and its potential as a theoretical foundation for foraging enrichment, we conducted two experiments with captive grizzly bears (Ursus arctos horribilis). In Experiment 1, bears were presented with five foraging choices simultaneously: apples, apples in ice, salmon, salmon in ice, and plain ice under two levels of food restriction. Two measures of contrafreeloading were considered: weight of earned food consumed and time spent working for earned food. More free than earned food was eaten, with only two bears consuming food extracted from ice, but all bears spent more time manipulating ice containing salmon or apples than plain ice regardless of level of food restriction. In Experiment 2, food-restricted bears were presented with three foraging choices simultaneously: apples, apples inside a box, and an empty box. Although they ate more free than earned food, five bears consumed food from boxes and all spent more time manipulating boxes containing apples than empty boxes. Our findings support the provision of contrafreeloading opportunities as a foraging enrichment strategy for captive wildlife.

The use of technology to enhance zoological parks

Technology can be used in a zoological setting to improve visitor experience, increase research opportunities, and enhance animal welfare. Evaluating the quality of these technological innovations and their use by nonhuman and human counterparts is a critical part of extending the uses of technology to enhance animal welfare and visitor experience at zoological parks. Survey data from a small sample of institutions housing primates suggest that computers, television, radio, and sprinklers are the most prevalent types of technological enrichment currently used. Survey respondents were positive about the technology implemented, stating a desire to increase its use.

The reduction of stereotypic pacing in tigers (Panthera tigris) by obstructing the view of neighbouring individuals

Until recently, little attention has been focused on the influence of social interactions and the presence of conspecifics on stereotypic pacing in captive carnivores. This study examined the effect of adding a visual barrier between two tiger (Panthera tigris) exhibits on stereotypic pacing behaviour. Continuous sampling was used to record the duration of time tigers spent pacing and the total number of pacing bouts. The results show a significant decrease in stereotypic pacing for the group of six female tigers after obstruction of the view of neighbouring tigers. These results suggest that the opportunity for tigers to view conspecifics in other exhibits may influence time spent pacing therefore it is felt that the design or renovation of tiger exhibits should take the visibility of neighbouring individuals into account.

Faecal glucocorticoid level is not correlated with stereotypic pacing in two captive margays (Leopardus wiedii)

The ‘coping hypothesis’ of stereotypic behaviour — that stereotypies are performed as a means of helping the animal to cope with its environment by reducing stress — was tested using two adult female margays (Leopardus wiedii), an endangered neotropical small cat species. Within-individual and between-individual comparisons of the duration of stereotypic pacing and glucocorticoid concentration, measured non-invasively in faeces, indicated that stereotypic pacing did not help the two margays to cope with their captive environment by reducing their physiological stress level. However, hiding appeared to serve as a coping function in the two margays, not by immediately reducing the faecal glucocorticoid concentration, but rather as a long-term effect.