The Influence of Visitor Effect and Environmental Enrichment on Stereotypic Behavior in an African Spurred Tortoise (Geochelone sulcata)

R. Richendollar , North Carolina Zoo

L.. Oakleaf, Dept. of Parks, Recreation, and Tourism Management,

North Carolina State University

North Carolina , USA

richendollar@gmail.com

Researchers have documented pacing as a form of stereotypic behavior in species ranging from primates to parrots (Mason, 2006) . Stereotypic behavior, while not a direct indicator of animal wellbeing, does correlate with an animal’s welfare (Mason, 2006; Swaisgood & Shepherdson, 2005) . Some studies have shown that the presence or absence of visitors can affect stereotypical behavior. Multiple researchers have examined the effect on captive animals of living in an enriched environment. However, few such studies have focused on reptiles.

This study examined the stereotypic pacing behavior of an African spurred tortoise (Geochelone sulcata) at the North Carolina Zoo. The animal was engaged in pacing behavior on a small path in her exhibit, and she continued the behavior despite attempts to distract her. The purpose of the research was to help pinpoint factors that influenced the pacing behavior. Researchers evaluated the impact of visitor density and exhibit design on the pacing behavior.

The study used the instantaneous sampling method for a total of 698 observations. Data were collected over a period of sixteen month from July, 2006 to November, 2007. This time frame allowed the researchers to observe the animal during different seasons and at varying visitor levels. On cooler days throughout the winter months, the tortoise was completely inactive. Data were not taken consistently from November through March, but rather were collected only when the temperature in her exhibit was above 52 degrees Fahrenheit. During this time, the animal was rotated to three different enclosures for the purpose of data collection. The enclosures represented an area with high traffic and medium levels of enrichment, an area with moderate traffic and high enrichment, and an area with no visitor traffic and no enrichment. We hypothesized that the least amount of pacing would occur in the enclosure with no visitor traffic. However, we found that both visitor density and a natural, enriched environment had an impact on the behavior.

The tortoise’s pacing behavior was significantly affected by the number of visitors at the individual exhibits during the observations. A chi square test of independence was calculated comparing pacing behavior with number of visitors present at the enclosures. A significant interaction was found (Χ2(4)=44.51, p<.001). Higher visitor traffic was associated with pacing behavior. However, the number of visitors present was not solely responsible for the level of pacing.

The various enclosures used for this study ranged from a heavily planted, complex exhibit to an enclosure with nothing but food and water. A chi square test of independence was calculated comparing pacing behavior with which exhibit the tortoise resided in. A significant interaction was found (Χ2(3)=49.65, p<.001). Although one of the enclosures was located at the hospital where there were no visitors present, the least amount of pacing was observed in the enclosure with the highest level of environmental enrichment. This exhibit included thick foliage and several natural places to forage and burrow. The only enclosure where researchers observed a higher than expected level of pacing also had the highest levels of traffic present.

This study indicates that the presence of visitors increased this animal’s stereotypic pacing, while an enriched environment helped to decrease it. This means that negative visitor effects may be ameliorated through the use of an enriched, natural environment and through design elements that make visitors less obtrusive. While it is impossible for zoos to keep their collections out of public view, this study indicates that some steps can be taken to ensure better animal welfare.

References:

Mason, G. (2006). Fundamentals and implications. In G. J. Mason & J. Rushen (Eds.), Stereotypic animal behaviour: Fundamentals and applications to welfare (2 ed.). Wallingford, Oxon CABI.

Swaisgood, R. R., & Shepherdson, D. J. (2005). Scientific approaches to enrichment and stereotypies in zoo animals: What's been done and where should we go next? Zoo Biology, 24, 499-518.