Term of Award

Winter 2001

Degree Name

Master of Science

Document Type and Release Option

Thesis (restricted to Georgia Southern)

Department

Department of Biology

Committee Chair

Bruce A. Schulte

Committee Member 1

C. Ray Chandler

Committee Member 2

Daniel Gleason

Committee Member 3

John Averett

Abstract

Human impacts such as pollution, habitat alteration, and boating have caused many injuries and deaths of the Florida manatee, Trichechus manutus latirostris. Rehabilitation centers have been established in Florida to help return sick or injured manatees back to the wild. Manatees that are released back to the wild after undergoing rehabilitation in captivity might lose some of their abilities to survive in the wild. A factor that might alter behavior in captive individuals was examined by determining if length of time spent in captivity influenced the behavior of manatees during rehabilitation. Even though all facilities follow similar guidelines, invariable differences exist at separate facilities because of housing conditions and management protocol. Differences in facilities, sex, and seasons also were examined. To determine if these factors influenced behavioral patterns, thirty-one manatees at six facilities during summer 2000 and twenty-seven manatees at five facilities during winter 2001 were observed.

Major behaviors (swim, feed, inactive and miscellaneous) were recorded once a minute for 180 minutes before, during and after a feeding period over three continuous days. No major differences in the behavior of captive manatees were found with lacilities, sex, or season. Hence, the entire captive manatee population sampled was examined to determine if length of time spent in captivity influenced behavior. Duration of time in captivity was expected to show significant differences because the longer an animal remains in captivity, the more its behavior is likely to be altered. However, length of time spent in captivity was not found to influence behavior. This study suggests that length ot time spent in captivity may not be an important factor when determining if an animal is releasable or not.

The second part of this study examined the social interactions of captive manatees during rehabilitation. Conflicts and aggression can become heightened in crowded conditions potentially creating competition over resources such as food, mates or space. Resolving conflict can occur when individuals leave a particular situation, defend territories, form small closely bonded groups through affiliation, or establish dominance hierarchies. Therefore, the objectives were to examine the number and type of agonistic and affiliative encounters, as well as determine if individuals within facilities developed frequent associations with certain manatees. Twenty manatees at four facilities were observed during winter 2001. All agonistic and affiliative encounters were recorded between individuals continuously for 180 minutes before, during, and after a teeding period for three continuous days. A total of 228 encounters were recorded, yet only ten interactions were aggressive. Sender-receiver tables were constructed based on aftiliative encounters between animals at separate facilities. Close bonding was observed between certain manatees at all facilities. The presence of social interacting and close association in captive manatees may be a way to prevent conflict in close confines, which suggests that manatees in captivity most likely acclimate to their new environment well and may be more social than previously thought.

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