Jun 26, 20187 min read

Water Feature Size and Stereotypic Behavior in Tigers

I worked on a group project where we were required to think of a testable question, conduct background research, collect data, present our results, discuss our findings, make connections to the broader field of research, and what our next steps will be in terms of adding to this study sample or changing the study altogether. We then had to write a paper (seen below) and present it as a PowerPoint presentation to our class. Data collection took place at the San Diego Zoo Safari Park, at their Sumatran tiger exhibit.

This was created as a group project for my Foundations of Inquiry course in Summer 2018.

Does a small water feature in an exhibit lead to a higher percent of stereotypic behavior in tigers than a large water feature?

Michelle Beeche, Tabitha Reed, Christopher Smith, Kera Young

Introduction:

In a zoo setting, tigers can exhibit stereotypic behaviors when stressed. There are many factors that can contribute to the display of stereotypic behavior. Previous research has defined stereotypic behavior as “repetitive, unvarying, and apparently functionless behavior patterns which captive animals develop as a response to physical restraint, lack of stimulation, or inescapable fear or frustration” (Mohapatra et al., 2014). The specific stereotypic behavior research has focused on is pacing. The definition of pacing is “Walking on a distance back and forth, immediately after this distance has been paced once in both directions” (Biolatti et al., 2016). Zoos look to reduce stereotypic behavior as much as possible particularly within the tiger’s environment.

There are studies showing that enrichment activities are beneficial to the welfare of tigers (Bashaw et al., 2003). The focus of this study was to determine if a smaller water feature in an exhibit leads to a higher percent of stereotypic behavior in tigers than a larger water feature. The prediction is that there will be a greater percentage of stereotypic behavior in the tigers that have a smaller water feature in their exhibit because previous research suggests that exhibits with access to a water pool with abundant clean water have substantial benefits on reducing stereotypic behavior. (Biolatti et al., 2016). This study is relevant because it provides information on how the design of tiger exhibits can reduce stereotypic behavior and potentially improve the overall well-being of the tigers.

Methods:

Sumatran tigers were observed in this study. The tigers observed consisted of one female tiger and three male tigers. Refer to Table 1 for detailed information on the subjects involved in this study.

Table 1: Detailed Information About the Study Subjects

All tigers are housed in individual “den” enclosures under tiger trail. Tigers are fed either once a day or twice a day depending on whether they will be on exhibit all day, on exhibit part of the day and then switched out, or not on exhibit at all. Refer to Appendix B for pictures of subjects.

Data for this study was collected from 9:00 AM to 12:00 PM (180 minutes) by instantaneous scans of the behaviors of all individual Sumatran tigers at 1-minute intervals (Altmann, 1974). An ethogram, a table for recording animal behavior or activity, was created with four behavioral categories (Bashaw et al., 2007). The four categories of behavior used in our ethogram where as follows: 1. Resting: lying down with eyes closed and no movement, 2. Resting but awake: lying down with eyes open and alert, 3. Pacing: Moving back and forth on a set path, similar to a figure 8, at least two times. (Mohapatra et al., 2014), and 4. Non Stereotypic Activity: any behavior other than rest, rest but awake, or pacing. Data was collected on data sheets that had a chart of the ethogram with time slots for data collection. (Refer to Appendix C for a sample data sheet) Observations were made from the public viewing areas around each enclosure when animals were on exhibit. Observations were made by four data collectors, split into teams of two with one team at each exhibit. Data was collected only once for each tiger. Subjects were credited with 1 minute of each behavior documented at each scan. Total percent of the time of behavior observed in each behavioral category was determined. Each of the tiger’s behavior was compared to their exhibit both individually and as a group when possible.

Results:

A combined total of 340 minutes of instantaneous scans were analyzed for the four tigers during the observation time. The tiger in Exhibit A spent 30.7% of her time resting (eyes closed), 61.4% resting (eyes open), 8.0% of her time in other non-stereotypic behavior, and 0% of her time in stereotypic behavior. The percent averages of activities for the tigers in Exhibit B were 0% of time resting (eyes closed), 32.5% resting (eyes open), 50.1% of their time in other non-stereotypic behavior, and 17.5% of their time pacing. Please see Figure 1 for a comparison between exhibit A and exhibit B and Figure 2 for the behavior time percentages of the individual tigers.

Figure 1

Figure 2

Discussion/Conclusion:

For this study, the stereotypic behavior observed was pacing. The female tiger, Majel, spent 0% of the time pacing in the small water feature enclosure. The three tigers that were in the larger water feature enclosure had a mean of 17.5% of the time pacing, with a standard deviation of ±15.1%. All four tigers observed did not interact with the water feature within their respective enclosure during our observations. The observational research suggests that the data rejects both the null hypothesis and alternate hypothesis. This study suggests that a small water feature in an enclosure does not lead to a higher percent of stereotypic behavior in tigers than an enclosure with a larger water feature. The results of our data actually suggest the opposite, that a large water feature in an enclosure increases the percent of stereotypic behavior in tigers than an enclosure with a smaller water feature. These results go against the information found in our current referenced research articles. However, inferential statistics must be conducted to see if the difference is truly significant.

Several uncontrollable variables could have affected the data collected in the study. During the data collection, the keepers decided to take Rakan off exhibit earlier than expected, which, in turn, ended his data collection. Rakan was separated from Moka, a paired buddy of ten months, the week prior to this study. This could have been why Rakan was showing signs of distress. Nelson was given access to exhibit B, with the larger water feature, after Rakan left and was in exhibit B alone for 50 minutes before Suka entered exhibit B. The number of data points available for all tigers in exhibit B ranged from 23 minutes with Suka to 83 minutes with Nelson, compared to the 176 minutes observed for Majel in exhibit A. In addition, Majel was involved in special enrichment for the tiger keeper talk starting at 11:45 AM. This was 15 minutes prior to the end of data collection. Majel was taken off exhibit for four minutes, 11:46-11:50 AM while the keeper added novel scents and food items to her enclosure. Majel’s 8% of other non-stereotypic behavior came after she was re-released into her exhibit with enrichment additives. All keeper talk activities were visible to exhibit B. Nelson's pacing was observed during the 15-minute keeper talk and could very well have resulted from the keepers being visible to him at his location of pacing. It has also been observed that pacing may occur at higher rates when large felids can see into the exhibits of their conspecifics (Rouck et al., 2005), but no pacing was observed with Nelson despite having visual access to Majel before the keeper talk began. Due to the large number of variables, small sample size, and relatively short observation time, further research into the whether the size of a water feature has an effect on either reducing or producing stereotypic behaviors in captive tigers is needed. Information gained could be useful in future exhibit design and improving the welfare of the animals housed in them.

Next Steps:

This study can be enhanced in a number of ways. One is that more research is needed involving tigers and the size water feature they have in their enclosure. More data could help continue this study by mentioning the specific size of exhibits and water features that could be useful in making comparisons. The accuracy of the results of this study could be improved by repeating observations over more days or adding more observation times during the day. It could also be improved by repeating observations of the same tiger in both exhibits A and B. Subsequent studies could also expand the behavioral categories being recorded in the ethogram. Mohapatra’s study in 2014 had 20 different behavioral categories.

Another way the study could be expanded is by focusing on gender, the age of the tigers, or their level of comfort based on how long they have been at the San Diego Zoo Safari Park. An associated study could be which tiger species spends more time in the water feature within the enclosure, the Sumatran tigers at the Safari Park or the Malayan tigers at the San Diego Zoo.

Literature Cited:

Altmann, J. 1974. Observational Study of Behavior: Sampling Methods. Behavior 49(3/4): 227-265.

Bashaw, M. J., Bloomsmith, M. A., Marr, M.J., & Maple, T. L. (2003). To Hunt or Not to Hunt? A Feeding Enrichment Experiment with Captive Large Felids. Zoo Biology 22(2), 189-198, ISSN: 0733-3188

Bashaw, M.J., Kelling, A.S., Bloomsmith, M.A., & Maple, T. l. (2007). Environmental Effects on the Behavior of Zoo-housed Lions and Tigers, with a Case Study on the Effects of a Visual Barrier on Pacing. Journal of Applied Animal Welfare Science, 10(2), 95-109, DOI: 10.1080/10888700701313116

Biolatti, C., Modesto, P., Dezzutto, D., Pera, F., Tarantola, M., Gennero, M. S., … Acutis, P. L. (2016). Behavioural analysis of captive tigers (Panthera tigris): A water pool makes the difference. Applied Animal Behaviour Science, 174, 173–180.

Mohapatra, R.K., Panda, S. & Acharya, U.R. (2014). Study on Activity Pattern and Incidence of Stereotypic Behavior in Captive Tigers. Journal of Veterinary Behavior, 9(4), 172-176; DOI: 10.1016/j.jveb.2014.04.003

Rouck, M. D., Kitchener, A., Law, G., & Nelissen, M. (2005). A comparative study of the influence of social housing conditions on the behaviour of captive tigers (Panthera tigris). Animal Welfare, 14(962), 7286th ser., 229-238.