Environmental Enrichment Devices Research Articles

Brushes and Shelters as Low-Cost Environmental Enrichment Devices for Loggerhead Turtles (Caretta caretta) During Rehabilitation

Brushes and Shelters as Low-Cost Environmental Enrichment Devices for Loggerhead Turtles (Caretta caretta) During Rehabilitation

Environmental Enrichment Devices Are Safe and Effective at Reducing Undesirable Behaviors in California Sea Lions and Northern Elephant Seals during Rehabilitation.

Environmental enrichment devices (EEDs) have been proven to promote positive wellbeing in zoos and aquariums, and support animals' reintroduction success; however, their use in rehabilitation centers is still limited. This pilot study investigated the safety and efficacy of three EEDs, Artificial Kelp, Horse KONG™ and Wubba Kong™, and their ability to decrease and/or eliminate undesired stereotypic behaviors or looking at staff/staff areas in seven wild California sea lions (CSLs) and eight northern elephant seals (NESs) undergoing rehabilitation in Southern California. Observers conducted instantaneous sampling once a minute during a 30-min baseline, followed by a 30-min EED implementation on one focal animal at a time. The data were analyzed with generalized linear mixed models (GLMM). All three EEDs were found to be durable and safe throughout the study. Our results show a significant reduction in stereotypical behaviors compared to no EED treatments in CSLs, with the most significant effect being with the Horse KONG™. The Wubba KONG™ and Artificial Kelp provisions also reduced the undesired behavior in both species of being focused on human caretakers. Individual preferences for specific EEDs were found within species and between species, with the NESs using EEDs more than the CSLs. This study highlights the beneficial aspect of EEDs for pinnipeds in rehabilitation centers for improving their quality of life.

Self-administration of a Salmonella vaccine by domestic pigs

Hand vaccinating is time consuming and inefficient. Oral vaccines delivered by drenching are less likely to be used due to a lack of labor on farms. Current environmental enrichment (EE) technologies do not allow pigs to express certain natural behaviors such as rooting and getting a reward. We developed a sprayer so that domestic pigs can self-apply any liquid. By adding an attractant (pig maternal pheromone), the use of EE devices by individual pigs can be increased. In this study, we used a Salmonella oral vaccine to evaluate efficacy of three delivery methods: (1) Control, no vaccine, (2) hand drenching as labeled, and (3) self-administration by this EE rooting device. All pigs sprayed themselves within 80 min of exposure to the EE device. While control pigs had little or no Salmonella serum and oral fluid IgG or IgA, hand-drenched and self-vaccinated pigs built similar levels of both serum and oral fluid IgA and IgG. We conclude we were able to significantly reduce human labor needed and achieved 100% efficacy in eliciting a serologic response when pigs self-administered a Salmonella vaccine. This technology could benefit commercial pig production while providing an enriched behavioral environment. Self-vaccination could also assist in control or immunization of feral swine and improve domestic pig health and food safety.

A review of welfare indicators for sea turtles undergoing rehabilitation, with emphasis on environmental enrichment

AbstractFor animals undergoing rehabilitation it is vital to monitor welfare in a way that is feasible, practical, and limits stress to the animal. The industry gold standard is to assess welfare under the Five Domains model, including nutrition, environment, physical health, and behaviour as the first four physical domains and mental domain as the fifth. Feasibility and effectiveness of these domains for assessing welfare of sea turtles undergoing rehabilitation were reviewed and it was determined that the mental state can be best assessed through behavioural changes. A scoping review of the literature was conducted using Scopus and Web of Science to investigate use of environmental enrichment devices (EEDs) as a measure of welfare in sea turtles. Behavioural assessments using EEDs were found to be well-documented; however, most EED studies pertained largely to livestock or zoo animals. Furthermore, studies rarely concentrated on reptiles, and specifically sea turtles. Results also showed that certain welfare assessment methods may be less appropriate for short-term captivity experienced during rehabilitation. Additionally, the hospital environment limits the ability to address some of the domains (ie biosecurity, feasibility, safety of turtle, etc, might be compromised). This review shows that only three of the nine environmental enrichment strategies described in the literature suit the specific requirements of sea turtles in rehabilitation: feeding, tactile, and structural. It is documented that turtles display behaviours that would benefit from EEDs and, therefore, more specific studies are needed to ensure the best welfare outcomes for sea turtles undergoing rehabilitation.

Does an Animal–Visitor Interactive Experience Drive Conservation Action?

Inspiring visitors to engage in conservation-related behaviour following a zoo visit is a primary objective for most zoos. Animal–visitor interactive (AVI) experiences are often central to this goal. Yet, these interactive experiences are insufficiently evaluated from both the visitors’ and captive animals’ perspectives. The current study took place at Fota Wildlife Park and involved the construction of an environmental enrichment device during an interactive visitor experience with Sumatran tigers (Panthera tigris sumatrae). It aimed to simultaneously encourage pro-conservation behaviour in visitors and promote animal welfare. Visitors (n = 51) completed a survey, observed the tigers’ behaviour and made a pledge to help tigers in the wild after completion of the AVI. Tiger behaviour was simultaneously observed by a trained researcher using occurrence or non-occurrence sampling, which found no indication that tiger welfare was compromised during the activity and was likely enhanced by engaging with the enrichment. Additionally, visitors observed a range of tigers’ behaviours. The results indicated that some visitors (8%) had continued with their pledge six weeks after the experience, and most visitors exhibited a high level of knowledge and a positive attitude towards tigers. The use of enrichment during AVIs may be a positive link between the visitor experience and animal welfare. These results can be used to guide AVIs in zoos which aim to connect people with nature and drive pro-conservation behaviour in visitors.

Naturalising diet to reduce stereotypic behaviours in slow lorises rescued from wildlife trade

Providing a natural diet is a key component to improving animal welfare and potentially reducing stereotypic behaviours in captivity. Wild slow lorises (Nycticebus spp.) are threatened by illegal wildlife trade, and in Thailand, confiscations from trade have led to a large number of Bengal (Nycticebus bengalensis) and greater slow lorises (N. coucang) in rescue centers such as Bang Phra Wildlife Domestic Research Station (Bang Phra). Due to limited enclosure space and availability of natural food items, welfare may be compromised for these confiscated animals. Slow lorises in most rescue centres including Bang Phra are mainly fed with fruit and vegetables rather than their natural diet of exudates, nectar and insects. Our project aimed to increase wild-type activities and reduce stereotypic behaviours in captive slow lorises at Bang Phra by modifying the diet (especially adding exudates of gum Arabic) using environmental enrichment devices. From May to August 2019, we implemented four diet conditions on 30 individuals: baseline, gum presented in two feeding devices and insects presented in a box. Diet conditions changed individual behaviours, with more time spent feeding and foraging, less time spent resting, and less stereotypic behaviours. Fixed gum was the most successful device to encourage increased feeding (40.4 % vs ∼ 3.5 % during baseline conditions) and foraging (16.3 % vs ∼2.5 % during baseline conditions), whilst significantly decreasing stereotypic behaviours (3.2 % vs ∼16.5 % during baseline conditions). Animals with small body sizes are often placed in small cages in rescue centres despite their needs in the wild. At the same time, species with specialist diets may not thrive in rescue centres that lack the funds or infrastructure to procure food items perceived to be specialised. With wild numbers declining rapidly, rescue centres must provide adequate space and wild type diets to ensure the health and well-being of these globally threatened primates.

Evaluating the influence of noise emitted by environmental enrichment equipment in routine farrowing management practices

The installation of fans and rooftop sprinklers in swine housing and management facilities can increase noise intensity and may impair workers' hearing health over longs periods of time; therefore, an assessment of the piglets’ stress during invasive practices was made. This study set out to evaluate the noise intensity emitted by environmental enrichment devices (fans and rooftop sprinklers) and by piglets restrained for body temperature assessments and its effect on animal welfare and on the hearing health of workers exposed to it for long periods. Twenty piglets ranging in age from five to twenty days were observed. The sow gestation area was divided into a cooled (fans and rooftop sprinklers) and uncooled area. Two decibel meters were used to measure noise intensity, one for the general noise in the facilities and the other for the piglets, with five-minute intervals between assessments. Digital thermometers were used to take the rectal temperature, and infrared thermometers were used to take the body surface temperature. Fixed-effects ANOVA for the housing environment and periods and multiple comparisons at a significance level of 5% were applied. The average dorsal temperature of the piglets was 36 °C ± 1.2 in the cooled area and 38.4 °C ± 0.5 in the uncooled area. In both periods, the average maximum noise intensity was over 100 decibels. In the afternoon, the maximum intensity was higher for the uncooled environment. The results indicate that neither the fans nor the rooftop sprinklers installed in the facilities nor the squealing piglets during restraint affect the noise intensity of the environment. However, the noise intensity demonstrates the piglets’ stress and the need for protective equipment to preserve the workers’ hearing health.

Paw preference in wolves (Canis lupus): A preliminary study using manipulative tasks

ABSTRACT Behavioural and brain lateralization is widespread among non-human vertebrates. Motor lateralization has been investigated in the domestic dog, revealing that “pawedness” in this species seems to be sex and task related; however, few if any studies considered this asymmetry in wolves (Canis lupus). The aim of this study was to investigate the paw preference of seven wolves housed at Parco Natura Viva – Italy, during the interaction with food-related (FD) and olfactory (OLF) environmental enrichment devices. Eleven sessions were done (22 session in total) per condition (FD and OLF), and data about enrichment manipulation were collected. Most of the wolves manipulated the enrichment devices using one paw rather than both paws. At the individual level, all subjects were lateralized in paw use, six were right pawed, one was left pawed (the alpha male) regardless of the enrichment condition. The fact that one paw rather than both was frequently involved in manipulation could indicate a practical advantage for each individual in being lateralized in paw use. Despite the small sample size, our results provide interesting insights about lateralization in wolves, deserving further investigations. More studies are needed considering factors such as temperament, social rank and task complexity on canid motor lateralization.

Efficacy of an interactive apparatus as environmental enrichment for common bottlenose dolphins (Tursiops truncatus)

AbstractEnvironmental enrichment is a key component in improving the psychological and physiological well-being of animals under professional care. Environmental enrichment involves the addition of stimuli, including objects and cognitive challenges, into the environment in order to increase species-specific behaviour and provide opportunities for choice and control. The effectiveness of enrichment should be evaluated on a case-by-case basis to determine if the desired result has been achieved. Environmental enrichment devices (EEDs) can be utilised to present novel problems to animals under professional care. Here, a submerged interactive cognitive apparatus was presented to eight bottlenose dolphins (Tursiops truncatus) five days a week for 18 weeks and behavioural indicators of animal welfare assessed. As a group, dolphins spent more time in social swims compared to solitary swims and more time at the bottom of the habitat than the middle or top throughout the day, even when the apparatus was not immediately available. Individuals’ differences were apparent in the type and amount of engagement with the apparatus. Three dolphins engaged with the apparatus by solving it or consuming the reward. Two dolphins, D4 and D8, engaged simultaneously with the apparatus and participated in more social swimming with each other. D4 solved the interactive apparatus and engaged in more social active and solitary active behaviours. D1 and D4 increased their use of the bottom of the habitat. This study is the first report of underwater enrichment increasing dolphins time at depth throughout the day even when the enrichment device is not available. The interactive apparatus was an effective form of enrichment for dolphins participating in successful trials.

Effect of environmental enrichment devices on behavior of individually housed beef heifers.

In research settings, certain experimental designs may require cattle to be housed individually. Individual housing of cattle may make the animals more susceptible to boredom and result the development of undesirable behaviors. The objective of this trial was to investigate the effects of different environmental enrichment devices (EED) on the behavior and feed intake of heifers. Twenty mixed-breed single-sourced heifers were used in a completely random design. Heifers were housed individually (3.05 m × 3.66 m) with the ability to have physical contact with adjacent heifers. Heifers were randomly assigned to one of the four EED treatments, including a jolly ball (JLY), a broom head (SRCH), a 182 cm 5-knot rope (RP), or a Pas-a-Fier roller (RLR). Behavior was recorded using 8 h long daily instantaneous scan sampling in 30 min intervals over three periods: 7 d prior to EED addition (PR), 7 d with EED (EDP), and 7 d after removing EED (PST). Standing, laying, eating, drinking, and exploratory behaviors were evaluated. Exploratory behaviors included: interaction with water trough, feed bunk, water pipe, pen gate, pen wall, EED, grooming, or allogrooming. Rumination behavior was also recorded during each observation time. Time standing and standing bouts were greatest for RP (P < 0.05), while JLY and RLR spent the most time lying down (P < 0.05). All heifers spent the majority of observation times lying down, followed by solely standing (P < 0.05). Heifers on the RP treatment interacted the most with their EED, followed by SRCH (P < 0.001). Rumination increased during EDP compared to PR (P < 0.001). These results suggest that a RP suspended from the ceiling in the pen may be used most frequently by individually housed beef heifers.

Comparisons of Activity Budgets, Interactions, and Social Structures in Captive and Wild Chimpanzees (Pan troglodytes).

Simple SummaryFor chimpanzees in zoos, the key aim of environmental enrichment is to enable them to exhibit behaviors, interactions, and societies similar to chimpanzees in the wild. A comparison of observational data, showed that the proportion of their time spent on collecting foraging was significantly lower in captive chimpanzees (located in Tama) than in wild chimpanzees (located in Mahale), but no significant difference was found between the two groups in terms of the proportion of their total time spent collecting, extractive, and hunting foraging. The percentage of time spent performing mutual grooming was much higher in Tama than in Mahale. Males, but not females, in Mahale formed a core social group, but no sex-specific differences were found in Tama. The multiple artificial feeders allowed chimpanzees in Tama to spend more time on extractive foraging to achieve a similar proportion of time on foraging as compared with that of the wild chimpanzees. The environmental enrichment for chimpanzees in Tama can be considered to be successful.Chimpanzees in zoos with sufficient and appropriate environmental enrichment devices are expected to exhibit behaviors, interactions, and societies similar to those in the wild. In this study, we compared the activity budgets of each observed behavior, characteristics of social grooming, and social networks of captive chimpanzees at Tama Zoological Park (Tama) with those of wild chimpanzees at Mahale Mountains National Park, Tanzania (Mahale), and tested our predictions. We surveyed 16 chimpanzees in both Tama and Mahale and recorded the behaviors and individuals in proximity of each focal individual and social grooming the focal individuals participated in. The proportion of time spent collecting foraging was significantly lower in Tama than in Mahale. Additionally, the percentage of mutual grooming was much higher in Tama than in Mahale. All focal individuals in Mahale performed mutual grooming interactions, including grooming handclasp (GHC) but this was not observed in Tama. The result of a high rate of mutual grooming in chimpanzees in Tama without GHC and the finding that individuals forming the core of their social network are sex independent suggest that chimpanzees placed in an appropriate environmental enrichment have idiosyncratic grooming or social features, even in captivity.

A novel environmental enrichment device increased physical activity and walking distance in broilers

Modern broilers are selected for fast growth and a large proportion of breast tissue, contributing to a top-heavy phenotype, leg disorders, and inactivity as birds reach market weight. Therefore, the objective was to motivate broilers to move through environmental enrichment. A total of 1,200 Ross 308 broilers were housed in pens of 30 for 6 wk: 600 birds were exposed to a novel laser enrichment device (LASER) and 600 were control. Each device projected 2 randomly moving red laser dots onto the floor 4 times/day for 4-min “laser periods.” Seven LASER and 7 control pens, with 5 focal birds/pen (n = 70), were randomly selected to be video-recorded day 0 to 8 and once weekly for the remainder of the trial. Videos were analyzed to measure broiler time-budget and behaviors such as latency to feed and distance walked during laser periods. Focal birds were gait scored weekly on-farm. A test of the human-approach paradigm was carried out on weeks 1 and 6 on all pens. LASER birds were more active on days 0, 1, 3, 4, 5, 7, and 8, moving 254% more on day 7 (P ≤ 0.05). Time spent active was increased in LASER treatment by 114% on week 2; 157% on week 3; 90% on week 4; and 82% on week 5. LASER birds spent more time at the feeder on days 0, 1, 2, 5, 8, and on weeks 1 and 5, with 84% more time at feeder than control on day 5 (P ≤ 0.05). LASER birds walked further during laser periods on day 0 to 8, reaching 646.5 cm greater (day 1), and on weeks 2, 3, 4, and 5, with an increase of 367.5 cm on week 2 (P ≤ 0.05). Over week 1 to 6, 60.54 ± 7.4% of focal birds in the laser treatment were at the feeder during or within 5 min following laser periods. The laser enrichment device was successful in stimulating broiler physical activity and feeding, and did not negatively impact walking ability.

A novel environmental enrichment device improved broiler performance without sacrificing bird physiological or environmental quality measures

Modern commercial broilers have been genetically selected for fast growth and heavy breast muscling, contributing to a top-heavy phenotype and increased leg lameness. A quick-growing phenotype coupled with poor leg health fosters inactivity. The objective of this study was to stimulate broiler movement using novel environmental enrichment and determine the impact of movement on production, leg health, and environmental parameters. A total of 1,200 Ross 308 broilers were housed in 40 pens with 30 birds/pen for 6 wk in 2 separate rooms (laser enrichment or control). Each enrichment device was mounted above 2 adjoining pens, projected 2 independent, randomly moving laser beams at the floor to stimulate innate predatory behavior, and was active 4 times daily in 4-min periods. Performance outcomes were calculated by pen and averaged per bird for each performance period and overall days 0 to 42. A total of 70 randomly selected focal birds were examined for breast blisters and footpad dermatitis each week and euthanized on day 42 for tibia quality measures. Air quality and litter moisture were sampled by week. Laser-enriched pens had greater average bird feed intake in starter (P < 0.001), grower (P = 0.004), finisher periods (P = 0.004), and overall days 0 to 42 (0.19kg/bird; P = 0.0003). Average bird weight gain was also increased in enriched pens in each performance period: starter (P = 0.043), grower (P = 0.001), finisher (P < 0.001), and overall days 0 to 42 (0.24kg/bird; P < 0.001). Enriched pens had improved feed conversion ratio (FCR) vs. control with a decrease of 3 FCR points in the grower (P = 0.031), 18 points in the finisher (P < 0.001), and 7 points overall (P < 0.001). Enriched pens had higher ADG during starter (P = 0.048), finisher (P < 0.001), and overall (5.7g/bird/d; P < 0.001). No differences were found in breast blister, footpad dermatitis, tibia, air, or litter quality measures (P > 0.05). In summary, a novel enrichment device based on bird visual feeding and predatory instincts positively affected performance through decreased FCR and increased ADG without sacrificing external animal-based measures, tibia quality, or air or litter quality.

Motion Illusions as Environmental Enrichment for Zoo Animals: A Preliminary Investigation on Lions (Panthera leo).

Investigating perceptual and cognitive abilities of zoo animals might help to improve their husbandry and enrich their daily life with new stimuli. Developing new environmental enrichment programs and devices is hence necessary to promote species-specific behaviors that need to be maintained in controlled environments. As far as we are aware, no study has ever tested the potential benefits of motion illusions as visual enrichment for zoo animals. Starting from a recent study showing that domestic cats are spontaneously attracted by a well-known motion illusion, the Rotating Snake (RS) illusion, we studied whether this illusion could be used as a visual enrichment for big cats. We observed the spontaneous behavior of three lionesses when three different visual stimuli were placed in their environment: the RS illusion and two control stimuli. The study involved two different periods: the baseline and the RS period, in which the visual stimuli were provided to the lionesses. To assess whether the lionesses were specifically attracted by the RS illusion, we collected data on the number of interactions with the stimuli, as well as on the total time spent interacting with them. To investigate the effect of the illusion on the animals’ welfare, individual and social behaviors were studied, and compared between the two periods. The results showed that two lionesses out of three interacted more with the RS stimulus than with the two control stimuli. The fact that the lionesses seemed to be more inclined to interact with the RS stimulus indirectly suggests the intriguing possibility that they were attracted by the illusory motion. Moreover, behavioral changes between the two periods were reported for one of the lionesses, highlighting a reduction in self-directed behaviors and an increase in attentive behaviors, and suggesting positive welfare implications. Thus, behavioral observations made before and during the presentation of the stimuli showed that our visual enrichment actually provided positive effects in lionesses. These results call for the development of future studies on the use of visual illusions in the enrichment programs of zoo animals.

Identifying a Milk-Replacer and Weaning Strategy for Holstein Calves Using Automated Behavioral Measures of Lying and Environmental Enrichment Device Use

Identifying a Milk-Replacer and Weaning Strategy for Holstein Calves Using Automated Behavioral Measures of Lying and Environmental Enrichment Device Use

Cosmopolitical encounters: Prototyping at the National Zoo in Santiago, Chile

ABSTRACTThis article presents an empirical reflection on how the prototyping of an environmental enrichment device for chimpanzees at the National Zoo of Chile precipitates a cosmopolitical encounter. Using material produced by design students, zookeepers and the chimps Judy and Gombe, we describe how prototyping iterations establish open processes of dialogue and encounters among humans and nonhumans. The case will demonstrate how prototyping can go further than the generation of models of an original. On the contrary, the cosmopolitical encounter emerging from the prototyping process makes evident a truly ontological vocation, acknowledging humans and other-than-human beings as singular entities. Its provisional and malleable nature turns this device into a privileged locus for the exploration of interspecies entanglement. Although zoos are scientifically organized institutions, in this case we observe how its anthropocentric hierarchy was performatively reshuffled at certain moments of the prototyping process. The cosmopolitical qualities of the prototyping process analyzed derive from its capacity to deploy an ethics of attention and care between the agencies at play, that is, for unfold gestures of mutual vulnerability. Finally, we propose prototyping as a device for moving from cosmopolitics as a way of understanding the world to cosmopolitics as a matter of design.

Assessment of environmental enrichment for different primate species under low budget: A case study

ABSTRACTThe 2011 European Union Zoo Inquiry presented evidence that most zoos fail to achieve adequate levels of nonhuman animal welfare. Appropriate environmental enrichment (EE) can play a role in the promotion of welfare. However, financial and staff constraints frequently make it challenging to implement EE on a daily basis. The aim of this study was to test how individuals of three different nonhuman primate species at the Maia Zoo in Portugal (white-handed gibbons, Hylobates lar; Mona monkeys, Cercopithecus mona; and brown lemurs, Eulemur fulvus) reacted to EE devices. Another aim was to investigate whether simple, inexpensive devices can have positive outcomes for animal welfare. The results showed that all individuals reacted to the EE intervention, but individual responses to the EE devices differed. EE devices had consistently positive effects for all three species as demonstrated by an increase in the expression of natural behaviors and a general decrease in abnormal behaviors (46% compared with baseline). This study demonstrates that it is important to simultaneously test multiple individuals from different species in different situations to evaluate the effectiveness of EE.

Εvaluation of an environmental enrichment device used for laboratory rabbits

Improving the housing conditions of individually caged laboratory rabbits using environmental enrichment devices is a source of concern in the scientific community and is encouraged in the guidelines of the local and international laboratory animal associations and national regulations. In this report, we inform on the results of an investigation whose aim was to evaluate the use of a commercially available shelter as an enrichment device for six individually caged rabbits (mean body weight 2.5 Kg) during their resting period. After an acclimatization period of five days in an animal room, a commercially available enrichment device, the Rabbit Hut (BioServ, New Jersey, USA), was introduced into every cage. After a 3-day familiarization period, the interactions of the rabbits with the device were video recorded for 12 hours during the light phase (06:00 – 18:00) on five consecutive days. Each rabbit’s interaction with the device was monitored and analyzed from the video recordings. We found that the rabbits used the enrichment device in different ways, which included passing through the device, staying under the device, gnawing the device, pulling and dragging the device using their teeth, and playing with the device. We also found that the rabbits mainly interacted with the device during the first two hours (06:00 – 08:00) and last four hours (14:00 – 18:00) of each 12-hour observation period of the 5-day investigation. Although the Rabbit Hut is marketed as an environmental enrichment item that could be used as a shelter for individually caged laboratory rabbits, our analysis of the interactions of individually caged laboratory rabbits with the device has generated new questions about the usefulness of the device and its benefit for the rabbits. However, further investigation is needed to clarify whether some of the expressed interactions indicate curiosity, interest or frustration with the item.

Zoo visitors’ perceptions of chimpanzee welfare are not affected by the provision of artificial environmental enrichment devices in a naturalistic exhibit

Zoo-housed animals are provided with many temporary elements in their exhibit, such as environmental enrichment devices (EEDs), which may not match the aesthetic of their exhibit. Some zoos object to the use of artificial EEDs in naturalistic exhibits, but there has been little research into whether the appearance of these temporary elements influences visitors’ perceptions. Therefore, we investigated visitors’ opinions about a naturalistic chimpanzee exhibit at Lincoln Park Zoo when EEDs were provided to the chimpanzees ( Pan troglodytes ). We wished to determine whether exhibit naturalism was important to visitors; what their perceptions were of the chimpanzees’ behaviour and emotions; what their thoughts were about the suitability of chimpanzees as pets; and whether these beliefs were affected by the type of EED in the chimpanzees’ exhibit. Eight EEDS were chosen for this study: four that were naturalistic in appearance and four that were designed to elicit similar species-typical behaviours, but were artificial in appearance. Visitors’ responses to the survey revealed that they generally believed that exhibit naturalism was important, and that the chimpanzee exhibit was naturalistic in appearance; they viewed the chimpanzees’ behaviour and feelings positively; and they did not think chimpanzees made good pets. Visitors’ responses to the survey questions did not differ whether artificial or naturalistic EEDs were provided in the exhibit. These results support previous research that zoo visitors are not affected by EED aesthetic in a naturalistic exhibit, perhaps because the naturalism of the exhibit supersedes any effect or because the EEDs represent such small elements within the exhibit.

Impact of Environmental Enrichment Devices on NTP In Vivo Studies

The goal of this study was to determine whether the use of nesting material or polycarbonate shelters as enrichment devices would have an impact on end points commonly measured during the conduct of the National Toxicology Program (NTP) 13-week studies. The study design was consistent with the NTP 13-week toxicity studies. Harlan Sprague-Dawley (HSD) rats and their offspring and B6C3F1/N mice were assigned to control (unenriched) and enriched experimental groups. Body weight, food and water consumption, behavioral observations, fecal content, clinical pathology, gross pathology, organ weights, and histopathology were evaluated. Enriched male mice and male and female rats exhibited decreased feed intake without a subsequent decrease in body weight; this may have been the result of the nesting material reducing the effect of cold stress, thereby allowing for more efficient use of feed. There were statistical differences in some hematological parameters; however, these were not considered physiologically relevant since all values were within the normal range. Gross pathology and histopathological findings were background changes and were not considered enrichment-related. Nesting material and shelters were used frequently and consistently and allowed animals to display species-typical behavior. There was no significant impact on commonly measured end points in HSD rats and B6C3F1/N mice given enrichment devices.