Welfare of Zoo Bears

for Animal Welfare class, 2017

Introduction

Positive welfare is a concept of welfare that goes beyond simply preventing negative experiences and outcomes (as some concepts of welfare do, for example the Five Freedoms, of which four are “freedom from” things considered bad) and is concerned instead (or additionally) with maximizing positive experiences and outcomes – positive welfare is concerned with pleasure, not just the absence of suffering.

Positive welfare can generally be measured similarly to negative welfare, but may be a bit more difficult to measure in some cases. Stress hormones are fairly straightforward to detect (for negative welfare), as are pleasure hormones (for positive welfare). Abnormal (e.g. stereotypic) behavior is an easy indicator of negative welfare, and play behavior is an indicator of positive welfare. It’s fairly straightforward to set up a system to test whether an animal chooses to pursue or avoid a thing, indicating positive welfare (if they acquire a thing they seek) or negative welfare (if they are subjected to a thing they seek to avoid). An animal’s environment need only be compared to their habitat in the wild to determine its naturalness (positive welfare) or lack thereof (negative welfare). On the other hand, disease, injury, and premature death are fairly easy to detect, but the concept of positive welfare in these areas poses a challenge, although good and consistent reproduction can be an indicator of positive health welfare.

This paper will assess the situation of bears in zoos and make recommendations for their positive welfare. I will be dealing with the extant species of bear (family Ursidae) other than polar and panda bears – among other things, the former has unique thermal and swimming requirements and the latter has unique dietary requirements and are notoriously fussy (especially in the realm of reproduction), whereas the other six are broadly more similar to each other in terms of welfare needs – specifically: the brown bear (Ursus arctos), the Asian black bear (Ursus thibetanus), the American black bear (Ursus americanus), the sun bear (Helarctos malayanus), the sloth bear (Melursus ursinus), and the spectacled bear (Tremarctos ornatus).

Research Summary and Analysis

Are They Healthy?

In negative terms, a healthy bear is one that is free of disease, injury, premature death, hunger, pain, and so on. But in terms of positive welfare, we can do better than merely that (although positive physical welfare is a bit more difficult to conceptualize than positive mental welfare). Bears should be fed a diet fit for their nutritional needs, not too much and not too little, and should be able to get a sufficient amount of exercise. Good reproduction is an indicator of good health, as is an appropriate weight (not too heavy, not too thin), a long life, and certain behavioral indicators, such as play (Held & Špinka, 2011).

Most bears have better lifelong health (e.g. sloth bears reproducing better, as in Forthman & Bakeman, 1992) when raised by their mothers, as opposed to those raised by human caretakers. However, there is a tradeoff in allowing bears to raise their own young – some mother bears may cannibalize their offspring, and bears who have been eaten as cubs tend to show poor welfare indeed.

Ambient noise is a rarely-considered aspect of welfare, but its effect on mothering behavior has been studied in sun bears by Owen, et al. (2013). In short, loud ambient noise increases mothering behavior, and is probably energetically costly during a time (cub-rearing) when there is little energy to spare.

A nutritionally healthy diet is important. Most bears in the wild eat more plant than animal matter and are opportunistic omnivores, eating anything from leaves, roots, and berries to insects, carrion, fresh meat, and fish; sloth bears in particular are adapted to be myrmecophagous. For a more natural and healthy diet, bread should be minimized; plants and meat or fish should be maximized.

Do They Feel Well Mentally?

It is important to keep bears entertained and active and displaying directed behaviors (indicating good mental welfare), rather than bored and passive and displaying stereotypic behaviors (indicating poor mental welfare). For this purpose, a variety of enrichment can (and ought to) be used (Shyne, 2006).

Feeding enrichment is among the most-studied forms of enrichment for bears. For Kodiak and grizzly bears (two subspecies of brown bear), ice blocks and “fishcicles” (whole mackerel or salmon frozen into ice blocks, sometimes with “layers of peanuts, apple pieces, raisins, peanut butter, and grape jelly, as well as scattered peanuts, bread, raisins, and sunflower seeds”) are a common (and apparently effective) form of enrichment, causing the bears to be more active and spend less time engaging in abnormal behaviors (Forthman, et al., 1992; McGowan, Robbins, Alldredge, & Newberry, 2009). Similarly, logs filled with honey are effective at reducing stereotypic and abnormal behaviors in sloth, American black, and brown bears, as is hiding food throughout an enclosure for bears to search for and collect (Carlstead, Seidensticker, & Baldwin, 1991). Offering food at unpredictable times is also effective enrichment in spectacled bears (Fischbacher & Schmid, 1999) and sun bears (Schneider, Nogge, & Kolter, 2014). Throwing food from the visitor area is suboptimal, seen to cause stereotypy in brown bears (Montaudouin & Le Pape, 2004); food should instead be hidden around the exhibit.

As with physical health, human-reared sloth bears tend to exhibit worse mental health than mother-reared bears, including self-directed and stereotypic behavior (Forthman & Bakeman, 1992). Male brown bears orphaned at an early age have been observed engaging in abnormal apparent fellatio behavior with each other, further suggesting that remaining with their mother for at least the first year of life is important for the lifelong mental health of a cub (Sergiel, et al., 2014).

Do They Live A Normal/Natural Life?

Female sloth bears are most social when exhibited with a familiar male and least social when exhibited with other females (Forthman & Bakeman, 1992). Social activity is often considered good for mental welfare (and as a practical matter exhibiting bears together decreases the total enclosure space required), especially in bears who have grown used to the presence of conspecifics (Mattiello, et al., 2014), but bears in the wild are famously solitary – considered the most asocial of the carnivorans – so for maximum naturalness, they should perhaps be exhibited alone and introduced to one another only for breeding.

Bears naturally range across a wide territory, so bear enclosures should be as large as possible – it is recommend that a single bear be housed in an enclosure of at least 2,500 m2, with an additional 1,000 m2 for each additional individual (Maślak, Sergiel, Bowles, & Paśko, 2015). Barren indoor enclosures are terrible for the bears, increasing stereotypies significantly – enclosures should be outdoors, but with ability to get away from inclement [M5] weather (Tan, et al., 2013). Slightly better is the common style of enclosure in older zoos: a small concrete area with a pool, with a moat separating the bears from visitors. This is insufficient [M6] – bear enclosures should provide opportunities to express natural digging, climbing, and tree-rubbing behavior; to wit: dirt and trees should be available (Maślak, Sergiel, Bowles, & Paśko, 2015).

Conclusion

One flaw with many areas of research on bear welfare (a flaw that almost all articles cited in this paper share) is small sample sizes: most studies are of only a handful of individuals at a single zoo; even the largest study is only a review of all of Poland’s zoo bears, which is still not very many animals. Unlike herd animals, who are kept in large groups that allow many animals to be studied, bears are usually kept alone or in pairs, only a few at each zoo, making it difficult to achieve high sample sizes in studies of zoo bears.

In some ways, recommendations about positive welfare are difficult to disentangle from recommendations about negative welfare. Increasing positive experiences in an area will tend to correspondingly decrease negative experiences in that area.

For maximum positive welfare in zoo bears, my research turns up three primary recommendations: outdoor enclosure space should be maximized, and enclosures should be fitted with dirt, trees, and pools rather than bare concrete; food should be varied, suitable to the bears’ natural diet, and presented interestingly (within logs or ice blocks, or hidden throughout the enclosure); cubs should be kept with their mothers for at least a year.

Food enrichment is the easiest and most achievable of these recommendations. All one needs to turn boring fish into entertaining “fishcicles” is a bucket, a hose, and a freezer. Hiding food throughout the enclosure may occupy a bit more keeper time than simply throwing the food to the bears, but is worth it for the animals’ mental health.

Keeping cubs with their mothers is sometimes risky, but for the lifelong health (mental and physical) of the bears, it is probably worth the risk except when the danger of cannibalism is very high.

Maximizing enclosure space and switching from bare concrete to dirt and trees will be the most difficult proposal for many zoos to enact. Zoo space is quite often simply limited, and increasing space for bears will decrease space for all the other animals. Moreover, even redesigning an exhibit without expanding it can be expensive, beyond the budgets of many zoos. Still, this should be done whenever space and budgets permit.

Works Cited

Carlstead, K., Seidensticker, J., & Baldwin, R. (1991). Environmental Enrichment for Zoo Bears. Zoo Biology, 10, 3-16.

Fischbacher, M., & Schmid, H. (1999). Feeding enrichment and stereotypic behavior in spectacled bears. 18, 363-371. doi:10.1002/(SICI)1098-2361(1999)18:5<363::AID-ZOO1>3.0.CO;2-H

Forthman, D. L., & Bakeman, R. (1992). Environmental and Social Influences on Enclosure Use and Activity Patterns of Captive Sloth Bears (Ursus ursinus). Zoo Biology, 11, 405-415.

Forthman, D. L., Elder, S. D., Bakeman, R., Kurkowski, T. W., Noble, C. C., & Winslow, S. W. (1992). Effects of Feeding Enrichment on Behavior of Three Species of Captive Bears. Zoo Biology, 11, 187-195.

Held, S. D., & Špinka, M. (2011, May). Animal play and animal welfare. Animal Behaviour, 81(5), 891–899. doi:10.1016/j.anbehav.2011.01.007

Maślak, R., Sergiel, A., Bowles, D., & Paśko, Ł. (2015, October 9). The Welfare of Bears in Zoos: A Case Study of Poland. Journal of Applied Animal Welfare Science, 24-36. doi:10.1080/10888705.2015.1071671

Mattiello, S., Brignoli, S. M., Cordedda, A., Pedroni, B., Colombo, C., & Rosi, F. (2014). Effect of the change of social environment on the behavior of a captive brown bear (Ursus arctos). Journal of Veterinary Behavior: Clinical Applications and Research, 9(3), 119-123. doi:10.1016/j.jveb.2014.01.002

McGowan, R. T., Robbins, C. T., Alldredge, J. R., & Newberry, R. C. (2009, October 8). Contrafreeloading in grizzly bears: implications for captive foraging enrichment. Zoo Biology, 484-502. doi:10.1002/zoo.20282

Montaudouin, S., & Le Pape, G. (2004, September 30). Comparison of the behaviour of European brown bears (Ursus arctos arctos) in six different parks, with particular attention to stereotypies. Behavioural Processes, 67(2), 235-244. doi:10.1016/j.beproc.2004.02.008

Owen, M. A., Hall, S., Bryant, L., & Swaisgood, R. R. (2013, December 17). The influence of ambient noise on maternal behavior in a Bornean sun bear (Helarctos malayanus euryspilus). Zoo Biology, 33, 49-53. doi:10.1002/zoo.21105

Schneider, M., Nogge, G., & Kolter, L. (2014, January 9). Implementing unpredictability in feeding enrichment for Malayan sun bears (Helarctos malayanus). 33, 54-62. doi:10.1002/zoo.21112

Sergiel, A., Maślak, R., Zedrosser, A., Paśko, Ł., Garshelis, D. L., Reljić, S., & Huber, D. (2014, June 4). Fellatio in captive brown bears: Evidence of long-term effects of suckling deprivation? Zoo Biology, 33, 349-352. doi:10.1002/zoo.21137

Shyne, A. (2006, April 19). Meta-analytic review of the effects of enrichment on stereotypic behavior in zoo mammals. Zoo Biology, 0, 1-21. doi:10.1002/zoo.20091

Tan, H., Ong, S., Langat, G., Bahaman, A., Sharma, R., & al., e. (2013, April). The influence of enclosure design on diurnal activity and stereotypic behaviour in captive Malayan Sun bears (Helarctos malayanus). Research in Veterinary Science, 94(2), 228-239. doi:10.1016/j.rvsc.2012.09.024