You might think that when it comes to enclosures for elephants—the largest land mammals on Earth—size matters.
But a new study suggests space isn’t as important for their welfare as social interactions and having an array of opportunities to engage with their surroundings.
The findings come from the largest multi-institutional zoo-elephant welfare project conducted to date, and includes nine studies that analyze the lives of 255 African and Asian elephants in 68 accredited North American zoos. The results appear in the journal PLOS ONE, including a companion overview.
“This is the first coordinated set of studies aimed at evaluating a number of behavioral and physical aspects of welfare for the North American zoo elephant population and, importantly, identifying the most important aspects of elephant management, housing, and care,” says Cheryl Meehan, a staff research associate in the population health and reproduction department in the School of Veterinary Medicine at the University of California, Davis.
The full research collection contains studies on elephant welfare factors including behavior, body condition, foot-and-joint health, female reproductive function, and walking distance.
Some of the results confirmed expectations. For example one of the studies found that spending time on hard flooring was the number one risk factor for both foot and musculoskeletal health problems, which were common in the elephant population.
Other findings revealed previously unknown links between elephant management and welfare. For example, a research team led by Joy Mench, professor of animal science, and graduate student Brian Greco found that more than three-quarters of the elephants studied performed stereotypic behaviors such as swaying or rocking.
These types of behaviors are considered to be among the most important behavioral indicators that the welfare of a captive animal is compromised, but their causes are difficult to pinpoint.
Further for elephants, spending time alone is an important risk factor, while spending more time in larger social groups, particularly those that include young animals, have a protective effect. Additionally, moving from zoo to zoo increases an elephant’s risk of performing stereotypic behavior.
Researchers believe the findings mean that the social lives of elephants play a large role in their behavioral health—so zoo elephant programs should consider management changes to support larger, multigenerational social groupings.
Some of the other results were quite surprising, Meehan says.
“We expected to find associations between the size of zoo exhibits and welfare, but space ended up being of minor importance when compared to social factors and management practices such as enrichment programs.”
For example, female elephants who experienced a wide variety of enrichment opportunities and feeding options, such as puzzle feeders that require work to gain access to food, were more likely to have normal reproductive function. This result indicates that day-to-day management practices could be an important tool in addressing the reproductive issues that are particularly common among female African elephants.
The researchers hope the findings will provide zoos with “objective information about how elephants are faring behaviorally, physiologically, and emotionally, and the positive and negative outcomes of various zoo housing and management practices.”
A National Leadership Grant to Honolulu Zoo Society from the Federal Institute of Museum and Library Services funded the work.
Source: UC Davis