Lindsay R. Mehrkam

Is preference a predictor of enrichment efficacy in Galapagos tortoises (Chelonoidis nigra)

It is widely acknowledged that environmental enrichment plays an important role in promoting the welfare of captive animals. However, a topic of debate is whether an animals preference for an enrichment strategy is any indicator of its efficacy. In addition, relatively few studies have evaluated environmental enrichment strategies for non-mammalian species. In the present study, we compared the results of an observational evaluation of enrichment efficacy with the results of a paired-stimulus preference assessment for three Galapagos tortoises. In the observational study, object enrichment (boomer balls and a free-flowing sprinkler) and keeper interactions (shell scrubbing and neck rubbing) were evaluated systematically for their effects on locomotion, species-typical behavior, aggressive and non-aggressive conspecific interactions, and enclosure. Preference assessments were subsequently conducted in which subjects could choose the enrichment strategy to be implemented. All subjects preferred keeper interactions consistently over object enrichment. Our results suggest that enrichment preference was a variable predictor of efficacy across enrichment species-typical behavior, activity levels, enclosure use, and aggressive and non-aggressive conspecific interactions strategies. Preference predicted efficacy for promoting species-typical behavior (1/3 subjects), activity levels (2/3 subjects), and enclosure use (2/3 subjects), but not conspecific interactions (0/3 subjects). The results suggest that preference may be an efficient predictor of enrichment efficacy when daily observational evaluations are not practical; however, the predictive utility of preference assessments may depend on the behavioral goal of the enrichment strategy. We discuss the need for future research examining the relationship between preference and enrichment efficacy-as well as other potential indicators of enrichment effectiveness-in captive animals.

Human Interaction as Environmental Enrichment for Pair-Housed Wolves and Wolf–Dog Crosses

Private nonhuman animal sanctuaries are often financially limited in their ability to implement traditional environmental enrichment strategies. One possible solution may be to provide socialized animals with human interaction sessions. However, the merit of human interaction as enrichment has received little empirical attention to date. The present study aimed to evaluate whether human interaction could be enriching for socialized, pair-housed wolves and wolf–dog crosses at a private sanctuary. Observations of each subject were conducted in a reversal design to measure species-typical affiliation, activity levels, and aberrant behaviors when caretakers were both present and absent. The results demonstrate significantly higher levels of conspecific-directed affiliation and activity levels and reduced aberrant behavior when human interaction was available. Social play also increased when caregivers were present, supporting the hypothesis that play among conspecifics may be maintained by positive changes in an animals environment. The potential for human interaction to be established as a scientifically validated, cost-effective enrichment strategy is supported by these findings.

Applying behavior-analytic methodology to the science and practice of environmental enrichment in zoos and aquariums

Environmental enrichment in zoos and aquariums is often evaluated at two overlapping levels: published research and day-to-day institutional record keeping. Several authors have discussed ongoing challenges with small sample sizes in between-groups zoological research and have cautioned against the inappropriate use of inferential statistics (Shepherdson, , International Zoo Yearbook, 38, 118-124; Shepherdson, Lewis, Carlstead, Bauman, & Perrin, Applied Animal Behaviour Science, 147, 298-277; Swaisgood, , Applied Animal Behaviour Science, 102, 139-162; Swaisgood & Shepherdson, , Zoo Biology, 24, 499-518). Multi-institutional studies are the typically-prescribed solution, but these are expensive and difficult to carry out. Kuhar ( Zoo Biology, 25, 339-352) provided a reminder that inferential statistics are only necessary when one wishes to draw general conclusions at the population level. Because welfare is assessed at the level of the individual animal, we argue that evaluations of enrichment efficacy are often instances in which inferential statistics may be neither necessary nor appropriate. In recent years, there have been calls for the application of behavior-analytic techniques to zoo animal behavior management, including environmental enrichment (e.g., Bloomsmith, Marr, & Maple, , Applied Animal Behaviour Science, 102, 205-222; Tarou & Bashaw, , Applied Animal Behaviour Science, 102, 189-204). Single-subject (also called single-case, or small-n) designs provide a means of designing evaluations of enrichment efficacy based on an individuals behavior. We discuss how these designs might apply to research and practice goals at zoos and aquariums, contrast them with standard practices in the field, and give examples of how each could be successfully applied in a zoo or aquarium setting.

The influence of breed and environmental factors on social and solitary play in dogs (Canis lupus familiaris)

The domestic dog is an ideal model species in which to study the genetic and environmental factors that influence play behavior. Dogs exist in a wide variety of breeds and frequently engage in multiple forms of play. In the present study, we investigated whether the levels of solitary and social play differed between dogs of three breed types with distinct predatory motor pattern sequences (herding dogs, retrievers, and livestock guarding dogs [LGDs]). Furthermore, we investigated how environmental factors (social and nonsocial contexts) influenced play in dogs of these breed types. Groups of breed-matched dyads with working experience and of equivalent age, sex, and neuter status ratios were exposed to four experimental test conditions and two control conditions in randomized orders. With respect to solitary play, environmental context did have a significant effect, with toys reliably producing the highest levels of solitary play across all breed types. Retrievers engaged in significantly higher levels of solitary play overall than LGDs, and there was a trend in comparison to herding dogs. In contrast, neither environmental context nor breed had a significant effect on social play levels; however, neuter status of the dyads did have a significant effect on social play, with mixed-status dyads engaging in significantly higher levels of social play than same-status dyads. Our findings provide experimental evidence for identifying proximate, environmental stimuli that reliably facilitate social and solitary play and discuss possible genetic (i.e., breed type) and lifetime influences on the form of play in domestic dogs.

A method to assess relative preference for training and environmental enrichment in captive wolves (Canis lupus and Canis lupus arctos)

It is currently debated as to whether or not positive reinforcement training is enriching to captive animals. Although both husbandry training and environmental enrichment (EE) have been found to benefit animal welfare in captivity, to date, no systematic investigation has compared an animals preference for performing a trained behavior to engaging freely with a stimuli provided as EE. In the current paper, we used four captive wolves to (1) test the efficacy of a paired-stimulus preference assessment to determine preference for engaging in a trained behavior as a choice; and to (2) use a paired-stimulus preference assessment to determine whether or not individuals prefer to engage in a previously trained behavior versus a previously encountered EE stimuli. Of the four subjects tested, visual inspection of the graphs revealed that two of the subjects preferred trained behavior stimuli and two of the subjects preferred EE stimuli; only one of the wolves had a statically higher preference for an EE stimulus over a trained behavior. We believe that letting the animals choose between these two events is the first step in answering the question of whether or not is training enriching, however more research needs to be done and suggestions for future research is discussed.

Effects of Enrichment Presentation and Other Factors on Behavioral Welfare of Pantropical Spotted Dolphin (Stenella attenuata)

ABSTRACT Environmental enrichment is a crucial element of promoting welfare for animals in captivity. However, enrichment programs are not always formally evaluated for their efficacy. Furthermore, there is little empirical evidence of enrichment evaluation for species of small cetaceans in zoological settings. A wide range of variables may potentially influence enrichment efficacy and how it in turn affects behavior. The purpose of this study was to determine the most preferred environmental enrichment, and method of presentation, for a species that has not been well studied in captivity, the pantropical spotted dolphin (Stenella attenuata). In order to determine which enrichment items and method of presentation were most effective at eliciting enrichment interaction, we systematically examined how several variables of enrichment influenced enrichment interaction. The results suggested that presenting enrichment after training sessions influenced interaction with the enrichment. The results also indicated preference for enrichment type and a specific enrichment device. Finally, factors that influenced interaction were also found to influence aberrant behavior. The results support the premise that enrichment be “redefined” for each species and each individual.