Effects of Enclosure and Environmental Enrichment on the Behaviour of Ring-Tailed Lemurs (Lemur catta)

Abstract

Environmental enrichment is widely used to improve the quality of life of animals under human care. To successfully implement enrichment programs, it is important to evaluate their effect in different enclosure types since housing conditions may change depending on external factors, such as husbandry, management, or seasonal variation. This study investigates how ring-tailed lemur (Lemur catta) behaviour changes with the availability of enrichment items and the type of enclosure the animals are housed in. Through observations, we compared the behaviour of the lemurs in an indoor and outdoor enclosure, both without and with enrichment items. Although we observed enrichment effects, we found that enclosure type had a bigger effect on the lemurs’ behaviour. Additionally, behavioural changes induced by enrichment items differed between indoor and outdoor enclosures. These results indicate that the effectiveness of enrichment items may depend on the enclosure in which they are provided and consequently suggest that the impact of these programs should not be generalised over enclosure types. This highlights that the evaluation of environmental enrichment programs remains important when optimising zoo animal welfare.

Enriching Zoo-Housed Ring-Tailed Lemurs (Lemur catta): Assessing the Influence of Three Types of Environmental Enrichment on Behavior

“…The general aim of the study is to promote the expression of species-specific behavioral patterns and reduce ABRs and stress-related behaviors. In particular, thanks to the social structure and stability of the selected group [ 46 ] and the predictable husbandry routine [ 7 ], we expect to find low levels of agonistic, explorative, scent-marking, foraging and locomotor behaviors, and a higher level of resting and stress-related patterns (e.g., yawning, self-scratching and self-grooming [ 40 , 41 ] compared to studies performed in the wild, as reported also by previous research on captive lemurs [ 16 , 30 , 32 , 36 ]. We also expect to detect the occurrence of ARBs, as found by other scholars, and a higher level of affiliative behaviors with respect to other captive studies conducted on breeding groups [ 16 , 36 ].…”

“…In particular, thanks to the social structure and stability of the selected group [ 46 ] and the predictable husbandry routine [ 7 ], we expect to find low levels of agonistic, explorative, scent-marking, foraging and locomotor behaviors, and a higher level of resting and stress-related patterns (e.g., yawning, self-scratching and self-grooming [ 40 , 41 ] compared to studies performed in the wild, as reported also by previous research on captive lemurs [ 16 , 30 , 32 , 36 ]. We also expect to detect the occurrence of ARBs, as found by other scholars, and a higher level of affiliative behaviors with respect to other captive studies conducted on breeding groups [ 16 , 36 ]. We hypothesize that the selected enrichment items will increase the expression of exploratory, foraging, locomotion and scent-marking patterns, reduce resting and stress-related behaviors, and have a neutral effect on affiliative and agonistic ones.…”

“…Available research on sensory enrichments (e.g., auditory, olfactory and visual enrichments [ 1 ]) mostly focused on testing olfactory stimuli that often had a limited effect on lemur behavior and time budget or lead to conflicting results on their impact on the overall welfare of the studied animals (see for example: Lemur catta , [ 34 ]; Varecia rubra [ 35 ]). Interestingly, Laméris and co-authors [ 36 ] analyzed the integrated effect of enclosure type (indoor vs. outdoor) and enrichment provision (food-based and olfactory stimuli) on the behavior of a group of ring-tailed lemurs and found that enclosure characteristics had a greater influence in comparison with the implemented enrichments. Finally, a recent study on physical enrichments [ 37 ] found that sleep environments enriched with soft and insulated material raised the duration of sleeping bouts in four lemur species, including L. catta , with potential benefits for the animals’ well-being.…”

Zoo Visitor Attitudes Are More Influenced by Animal Behaviour than Environmental Enrichment Appearance

“…Providing appropriate enrichment items can increase the activity level and natural behaviour of the animals by offering them opportunities to engage in species-appropriate behaviours [19,35,38]. It has been suggested that observing active and engaged animals could promote positive visitor perceptions towards them [28].…”

“…In these items, a third of the lemurs' daily diet was included to avoid overfeeding. All devices used in this study had been previously offered to the lemurs during another research conducted by our group [35], and were therefore not novel to the animals.…”