Possible Influences of Positive Scent Stimuli on the Behavior of Captive Polar Bears (Ursus maritimus)
Shannon L. Fredebaugh, Eduardo J. Fernandez, and William Timberlake
Indiana University and the Indianapolis Zoo
- Tundra: behaviors did not seem to change overall, but exhibited more food oriented behaviors during the spray time (t = 1.835, p = .096).
- Significant decreases in inactivity before and during the spray periods (t = 2.384, p = 0.028; t = 2.173, p = 0.043).
- Stereotypic behaviors increased before the spray and inactivity decreased after the spray (t = 2.043, p = 0.056; t = 1.750, p = 0.097).
- Triton’s enclosure use, grooming, and activity levels increased when he was alone (t = 2.015, p = 0.059; t = 1.974, p = 0.064; t = 2.368, p = 0.029).
- Polar Bear Background
- In the wild, polar bears may travel 1,200 to 2,500 miles during seasonal migrations and up to 15 miles a day to find food (Reeves, Stewart, Clapham, & Powell, 2002).
- Foraging is engaged through smell since polar bears have such sensitive noses that they can smell a seal more than 20 miles away (Domico, 1988).
- Many predatory animals in zoos exhibit stereotypic behaviors – pointless repetitive activities – often related to feeding time (Grindod & Cleaver, 2001; Carlstead, Seidensticker, & Baldwin, 1991).
- Enrichment in the form of food and other food-related stimuli can disrupt stereotypic activities.
- Fixed time intervals using food helped to decrease stereotypic behaviors (Fernandez & Timberlake, 2004).
- Hypothesis: Scent stimuli should provide cues to encourage focal search behaviors, thus disrupting general search foraging loops (i.e., stereotypic activity).
Figure 2: Tundra’s Classes of Behaviors Before, During and After Spray Presentation
Figure 1: Triton’s Classes of Behaviors Before, During and After Spray Presentation
- The increase in food-oriented behaviors suggests that Tundra did attend to the scents. However, the scents had no effect on her other behaviors.
- Polar bears are solitary animals in the wild, and this may help explain Triton’s increase in activity and exhibit use when Tundra was not on exhibit.
- The spray may not have been as effective due to external stimuli including other scents, such as seals next to their exhibit and food in zoo.
- The spray elicits decreases in inactivity. However, the lack of consumption may not allow for the completion of foraging activity, and thus may exacerbate stereotypic activity.
- Tangible food/objects appear to have a greater effect for a longer time on decreasing stereotypies (Altman, 2000; Frenandez & Timberlake, 2004).
- Two polar bears at the Indianapolis Zoo
- A female, named Tundra and a male named Triton
- Both are captive born
- Tundra is 20 years old and Triton is 9 years old
Figure 3: Entropy Before, During and After Spray Presentation
Figure 4: Triton’s Classes of Behaviors and Entropy Depending on Tundra’s Presence
- Ethogram - General behaviors observed for a given animal or species – 21 behaviors and 7 classes of behaviors
- Stereotypies – pace swimming, pacing, and circle swimming
- 1st Set of Baseline (BL) – 5 days of regular observations – no spray bottle
- 1st Set of Spray (FT-1’)– 5 days of “polar bear spray” on fixed time interval
- Five sprays each minute for middle half hour
- Both sets were repeated, but 2nd BL with water spray bottle on FT-1’
- Instantaneous time samples – every 15s
- Altman, J. D., (2000). Effects of Inedible, Manipulable Objects on Captive Bears. Journal of Applied Animal Welfare Science.
- Carlstead, K., Seidensticker, J., & Baldwin, R. (1991). Environmental enrichment for zoo bears. Zoo Biology, 10, 3-16.
- Domico, Terry. Bears of the World. New York: Facts On File, 1988.
- Fernandez, E. & Timberlake, W.(2004). Fixed-Time Food Schedules and Their Effects on Activity Patterns in Two Adult
Polar Bears (Ursus maritimus).
- Grindod, J. A. E. & Cleaver, J. A. (2001). Environmental Enrichment Reduces the Performance of Stereotypic Circling
Behaviour in Captive Common Seals (Phoca vitulina). Animal Welfare, 10, 53 – 63.
- Reeves, R. R., Stewart, B. S., Clapham, P. J., & Powell, J. A. (2002). National Audubon Society Guide to Marine Mammals of
the World. New York (NY): Chanticleer Press, Inc. 39 p.
Ohio Wesleyan University
HWCC Box No. 1689
Delaware, OH 43015
Thanks to Sarah Goss-Robertson and India Swearingen for helping collect data.
= significant (p = .05)
= approaching significance (p = .10)