2012 COURSE DATES: AUGUST 4 – 17, 2012 - Sirenian International

142 Harper and Schulte
each other in nearly equal number, while never initiating aggressive contacts to one
another. This contrasted with the relationship to the orphaned, nine-month-old
male, who received aggressive and non-aggressive contacts. The two adult females at
Epcot showed a similarly reciprocal level of non-aggressive contact initiation as
those at Lowry Park Zoo. Such equal initiation of contacts suggests an absence of
dominance but with only a few animals, statistical analysis is not appropriate.
In wild manatees, affiliative social interactions have been observed between
adult females [Koelsch, 1997]. Mothers and calves associate regularly [Hartman,
1979; Reynolds and Odell, 1991; Koelsch, 1997], but it is uncertain if this
relationship lasts until adulthood as exhibited by the captive manatees in subgroup
one at HSWSP. Elephants are the closest living relative of the Sirenia, and they form
close mother–calf associations that last into adulthood for females [Buss and Smith,
1966; Eisenberg et al., 1971; Douglas-Hamilton, 1972; Moss 1976; Dublin, 1983].
The calf learns basic life skills from its mother and social group members [Lee and
Moss, 1999], and young males have even been observed play mounting with their
mothers or other females within their group [Gadgil and Nair, 1983]. Similar play
behavior toward adult female manatees was observed with juvenile males at Sea
World. In the wild, juveniles seem to be submissive to adult manatees [Hartman,
1979], perhaps explaining the prevalence of aggressive contacts initiated by the adult
females toward the juvenile male, Lowry. The types of associations observed with
captive manatees are similar to those described by other mammals in captivity
including elephants [Schulte, 2000], zebras [Schilder, 1992], captive spotted hyenas
[Glickman et al., 1997], and bonobos [de Waal, 1995].
In the case of manatees, understanding relationships in captivity and the wild
becomes especially important in the rehabilitation and eventual release of manatees.
Releasing manatees near where they were captured may be beneficial because
tradition is probably important in manatee survival [Bengtson, 1981]. Manatees may
learn feeding and resting areas among other information from older conspecifics
during development. Like elephants [McComb et al., 2001] and cetaceans [Wells
et al., 1999], manatees may have population level, behavioral diversity related to
cultural traditions. Associations between individuals beyond weaning may be vital in
manatee society and enhance survivorship. Such information could be helpful for
rehabilitation and conservation. To our knowledge, in the instances of simultaneous
releases of manatees from captivity, associations established in captivity have not
been maintained (at least five: female and a surrogate calf, two pairs of males, one
female pair and one mixed sex pair; R. Bonde, Sirenia Project, personal
communication). The sample size, however, is relatively small. Our data suggest
that females do establish some particular association groups in captivity, but further
study is needed to assess to what degree such associations are a result of captivity. In
terms of captive manatee management, density did not seem to have any negative
effects on manatee behavior and social aggregation of manatees seems to be a
normal condition of captive living.
CONCLUSIONS
Captive female manatees at different facilities carried out regular non-aggressive
contacts among conspecifics. Aggressive interactions were rare and not associated
with feeding periods. The rates of non-aggressive contacts were density dependent