The behavioral effects of exhibit size versus complexity in African elephants: A potential solution for smaller spaces

Abstract

Population‐level analyses suggest that habitat complexity, but not necessarily space availability, has important welfare outcomes for elephants in human care. At the Dallas Zoo, the opening of a new exhibit complex allowed us to measure the behavior of two female African elephants across three treatments to evaluate the independent effects of complexity and space. Preoccupancy observations were conducted in the elephants’ older exhibit, which consisted of a smaller, more simple yard (630 m2). Subsequent postoccupancy observations measured behavior in two different spaces in the new exhibit: a larger, complex yard (15,000 m2), and a smaller, but complex yard (1,520 m2). The elephants’ overall activity levels were greater in complex habitats, regardless of their size. Similar effects of habitat complexity oversize were observed with greater rates of foraging and lower rates of being stationary. Furthermore, elephants were out of view of visitors significantly more in the small, simple yard compared to either of the more complex habitats. However, exhibit size affected the incidence of stereotypic behavior (with lower rates of stereotypy in the larger exhibit compared to the smaller yards) and investigatory behavior (elephants investigated their environments more with increasing size and complexity). Behavioral diversity also increased with exhibit size and complexity. These results indicate that space availability alone is not sufficient to enhance the behavioral welfare of zoo elephants. Therefore, facilities with limited space can still encourage species‐appropriate behaviors and improved welfare for the elephants in their care by converting a small, simple area into a more complex habitat.

Behavioral Diversity as a Potential Indicator of Positive Animal Welfare

“…While three studies have found a significant inverse relationship (Asiatic lion [ 22 ], New Zealand white rabbits [ 23 ], bottlenose dolphins [ 24 ]), a study on two bear species found no significant relationship [ 25 ]. Studies examining both behavioral diversity and stereotypic behavior but not comparing them statistically have generally found that when stereotypic behavior is high or increased, behavioral diversity is low or decreased (sows [ 21 ], small felids [ 26 ], large felids [ 27 ], giant pandas [ 28 , 29 ], spectacled bears [ 30 ], chimpanzees [ 31 ], African elephants [ 32 ], parakeets [ 33 ], and songbirds [ 34 ]). Similarly, pharmacologically induced stereotypic behavior was also associated with lower behavioral diversity [ 35 ].…”

“…In total, across 28 studies, there was a reported increase in behavioral diversity (decrease for lack of enrichment) for 78.6% of the studies, with the remaining 21.4% reporting no significant difference. Species that experienced an increase in behavioral diversity following enrichment or an enhanced habitat included big cats [ 27 , 45 , 46 ], leopard geckos [ 38 ], parakeets [ 33 ], capuchins [ 40 ], African cichlid males [ 47 ], pigs [ 21 , 48 , 49 , 50 ], wombats [ 39 ], red foxes [ 51 ], bottlenose dolphins [ 52 ], ghost bats [ 53 ], bears (spectacled [ 30 ], Andean, sloth, brown, and black [ 54 ]), rats [ 55 ], African elephants [ 32 ], small felids [ 26 ], hognose snakes [ 56 ], giant pandas [ 28 , 29 ], and chimpanzees [ 31 ]. Species where enrichment or improved habitat was not found to significantly change behavioral diversity include armadillos, bush babies, and two toed sloths [ 57 ], wolves [ 58 ], African elephants [ 59 ], zebra fish and checker barbs [ 60 ], and lions [ 41 ].…”

Supporting Zoo Asian Elephant (Elephas maximus) Welfare and Herd Dynamics with a More Complex and Expanded Habitat

“…The compression of space available to wide-ranging animals (e.g., large carnivores, elephants, primates) in zoos is often perceived as detrimental to their welfare; however, there is evidence of effective strategies in safeguarding welfare by addressing habitat quality in a taxa-specific manner, providing appropriate mental stimulation and cognitive opportunities [ 33 ]. The lack of association in previous studies of habitat size to walking distance [ 37 ] or activity level [ 168 ] challenges the assumption that elephants will choose to walk greater distances if provided with more room. Furthermore, the aforementioned associations of increased walking distance and activity level with dynamic feeding regimes and habitat complexity suggest that space may be important to the extent that it can support greater habitat flexibility and complexity to promote species-typical behaviors and allow individuals more choices [ 33 , 159 ].…”

Behavioural Diversity Study in Bottlenose Dolphin (Tursiops truncatus) Groups and Its Implications for Welfare Assessments

“…This shows the importance of providing cetaceans in zoological park settings with appropriate and well-defined enrichment programs. In studies on other species, behavioural diversity also increased while enrichment was provided (e.g., big cats [77,78], pigs [79][80][81], bears [82,83], elephants [84] and giant pandas (Ailuropoda melanoleuca) [85]).…”