Social interactions in captive female Florida manatees

Abstract

The Florida manatee (Trichechus manatus latirostris) is considered a semi-social species with strong bonds developed primarily between mother and offspring. Some field studies suggest sociality may be more developed and such social relationships may facilitate survival. Seven facilities in Florida house manatees, many of which were brought into captivity because of injury or illness sustained in the wild. Decisions to release such manatees consider individual history and health. We examined social interactions in adult female captive manatees to assess level of association and implications for manatee care and release. We investigated the degree of contact among 20 manatees in captivity at four facilities housing two to nine adult female manatees. We used all contact behavior occurrences sampling and continuous recording for 180 continuous minutes per day over 3 consecutive days at each facility. Virtually all contacts were non-aggressive. The number of contacts between manatees increased as the number of manatees per unit volume of water increased. Contacts did not fit a Poisson distribution, however, and were not random. When more than two manatees were present, manatees only associated with a subset of individuals in the aquarium. Relationships maintained in captivity indicate the potentially social nature of manatees, and suggest that further research is needed to examine the benefit of these relationships to the health and rehabilitation of manatees in captivity and conservation in the wild. Zoo Biol 24:135–144, 2005. © 2005 Wiley-Liss, Inc.