Newsroom: “Beary” Complex Enrichment for Captive Malayan Sun Bears Newsroom:

Due to their extensive foraging activities, bears prove to be challenging animals to keep stimulated in a captive environment. They are easily prone to developing stereotypic behaviors (e.g., pacing), a type of abnormal repetitive behavior. These behaviors can be a sign that something is missing from an animal’s environment, and that the animal is currently or has in the past experienced poor welfare. To decrease stereotypic behaviors, provide opportunities to engage in species-typical foraging behaviors, and encourage more decision-making and problem-solving, zoos often integrate enrichment devices that can give animals the chance to work for their food (e.g., feeding enrichment that challenges an animal to spend more time locating, acquiring, and handling their food).

Researchers at Sonoma State University recently published a study that investigated whether providing complex feeding enrichment devices decreased stereotypic behavior and increased enrichment use for captive Malayan sun bears (Helarctos malayanus). The Malayan sun bear is native to the tropical rainforests of Southeast Asia, and is the smallest and least-studied of the eight-bear species [1]. These opportunistic omnivores have long claws and strong teeth to help in digging, climbing, and tearing into logs.

Sun bears use their 8–10 inch long tongues to extract honey and insects from small spaces; hence why they are also known as the “honey bear.” Photo by: Steven Gotz.

There is some evidence that providing complex enrichment decreases the performance of stereotypic behaviors and increases investigative and foraging behaviors in black bears [2] and sloth bears [3]. Researchers conducted a study to find out if manipulating the same enrichment devices for more complexity would reduce the performance of sun bear stereotypic behavior, and ultimately benefit their welfare.

The researchers’ designed two enrichment devices, honey-log and PVC cross-shaped feeder, that were presented to the bears at three different levels. With each increasing level there was an additional task or challenge to test the bears’ learning skills. After three weeks of baseline data collection, the complex enrichment was introduced three times a week, per level over six weeks. The sun bears had the opportunity to engage with each level three times, on alternating days to maintain interest in the enrichment. Stereotypic behavior was recorded continuously using video-cameras, and researchers also did in-person observations to determine the percent of time the sun bears spent interacting with the enrichment devices.

Overall, researchers found that providing the enrichment devices decreased stereotypic behavior in the sun bears, and the devices with greater complexity usually caused a greater reduction in stereotypy, compared to their behavior prior to receiving the enrichment. During the six weeks, the stereotypic behavior was significantly less on the days the devices were present compared to when they were absent. Surprisingly, increasing the complexity of the enrichment devices had variable effects on enrichment use: sun bears spent more time using the PVC cross-shaped feeder when they were more complex, but less time using the honey-log when they were more complex.

This research provides further support that providing enrichment devices designed to encourage problem-solving may help reduce the performance of stereotypic behaviors in captive animals. However, the relationship between enrichment and stereotypic behavior is not straightforward. The causes of stereotypic behaviors are complex, and these behaviors can be highly persistent even after the animal’s environment is enriched [4]. Furthermore, the length of time spent with enrichment may not predict how important it is for the animal [5]. For example, interacting with a complex enrichment device for a short period of time may still provide sufficient stimulation and reward to reduce an animal’s stereotypic behaviors. Another complication is that the appropriate level of enrichment complexity may vary among different individuals [6]; think about how some people get frustrated while others become engrossed when presented with the same puzzle. Overall, this research suggests a promising option for decreasing abnormal repetitive behaviors: modifying the same enrichment devices to be more challenging.

For More Information

Ghavamian, Y., Minier, D., & Jaffe, K. E. (2022). Effects of Complex Feeding Enrichment on the Behavior of Captive Malayan Sun Bears (Helarctos malayanus). Journal of Applied Animal Welfare Science, 1-15.


Click the YouTube link below to watch “Bulan” interacting with level 2 of the PVC cross-shaped feeder device. Video by: Steven Gotz.

Yasmeen Ghavamian is an Animal Biology PhD student in the Animal Behavior & Cognition Lab at UC Davis. This sun bear research is the result of her master’s thesis, which continues to fuel her interest in studying animal behavior in zoological settings. Yasmeen’s current dissertation research is focused on investigating if captive gray wolf (Canis lupus) personality can predict consistency in problem-solving performance.


[1] Te Wong, S., Servheen, C., & Ambu, L. (2002). Food habits of Malayan sun bears in lowland tropical forests of Borneo. Ursus, 13, 127–136.

[2] Carlstead, K., Seidensticker, J., & Baldwin, R. (1991). Environmental enrichment for zoo bears. Zoo Biology, 10(1), 3–16.

[3] Veeraselvam, M., Sridhar, R., Jayathangaraj, M. G., & Perumal, P. (2013). Behavioural study of captive sloth bears using environmental enrichment tools. International Journal of Zoology, 2013, 1–6.

[4] Mason, G. J., & Latham, N. R. (2004). Can’t stop, won’t stop: Is stereotypy a reliable animal welfare indicator? Animal Welfare, 13, 57–69.

[5] Decker, S., Lavery, J. M., & Mason, G. J. (2023). Don’t use it? Don’t lose it! Why active use is not required for stimuli, resources or “enrichments” to have welfare value. Zoo Biology, DOI: 10.1002/zoo.21756

[6] Meehan, C. L., & Mench, J. A. (2007). The challenge of challenge: Can problem solving opportunities enhance animal welfare? Applied Animal Behaviour Science, 102(3–4), 246–261.

[Edited by Isabelle McDonald-Gilmartin and Jessica Schaefer]

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