International Giant Otter Studbook Husbandry and Management

oth cubs were adopted by a wild otter family that resided within their study area. During this
particular study, no other observations were made after that point. It has to be noted that this was
not a long-term study nor was it scientific. The long term ability to survive, find a mate, and rear
offspring can not truly be evaluated by 3 observations in a one month period. Update: in 2003, a
follow up was published (Gomez 2003) which explains that three reports were received where
the handreared female was identified five years after her original release. (The identification was
made by three persons, who were not involved in the handrearing or rehabilitation program for
the otters.) This female was observed with a family group which included four giant otters in
total. The author explains, that these reports “indicate that this not so young otter (6 years old),
is now the head (alpha female) of one small group comprising four otters, two adults and two
juveniles (probably her cubs). This follow up study does not mention if the rehabilitated and
released male otter was seen again since the conclusion of the first study. Gomez also states “As
a preliminary conclusion, the rehabilitation process appears to have been successfully achieved,
i.e. that the individuals were capable of surviving and behaved as normal wild giant otters,
completely independent and able to breed.” This follow-up report can not be considered
scientific or to be carried out over a long-term. In another case, WSPA (World Society for the
Protection of Animals) attempted to release a young confiscated handreared giant otter in
Colombia. This attempt was unsuccessful as the otter kept on returning to the people that tried to
release it. The otter was later placed at Cali Zoo where it still lives (Corredor, pers. comm.).
Unfortunately, no scientific long-term studies have been carried out on the survival success of
the other handreared orphaned wild giant otters that are known to have been reared/hacked
out/rehabilitated for release and returned back into the wild. Those animals, which went through
these processes at Karanambu Ranch in Guyana, constitute the majority of the total number of
giant otters that are known to have been rehabilitated for release and finally released. Reports
have shown the combined mortality rate of those animals during the rearing/hacking
out/rehabilitation process for release (which at Karanambu includes letting the otters have access
to wild conditions or/and access to the wild when they are unmonitored and on their own) and
those remaining surviving otters that were finally fully released was very high (i.e. the majority
did not survive). This was because most of those otters were assumed or known to have been
killed or were not seen again (i.e. see the reasons listed above and below). Below, are details on
the aforementioned experiences.
“From 1985 to 2003, thirty-four orphaned giant otters (22 males, 12 females) were hand raised
for eventual return to the wild at The Karanambu Cattle Company Limited Ranch (Karanambu),
on the Rupununi River in Guyana, South America. Young giant otters brought to Karanambu
ranged in age from 2 weeks to 9 months old; most were young cubs (8-10 weeks). Feeding,
housing, exercising, veterinary care, and rehabilitation protocols for young giant otters were
developed during this period. Six giant otter orphans died during the early stages of hand rearing;
two of these were killed, one by a caiman and one by another orphaned otter. Twenty-eight
orphans were successfully reared at Karanambu, and then began the process of rehabilitation.
During the early stages of their return to the wild, the giant otters would spend days and then
nights on the Rupununi River away from human care, often interacting with wild giant otters.
One male giant otter was never rehabilitated, remaining at Karanambu for four years until wild
otters killed it. Six giant otters were killed before they were considered completely rehabilitated,
including three killed by people and three by other giant otters. Another four giant otters were
presumed dead, presumably also killed by people. Sixteen of the orphaned giant otters (57% of
those that began the process of rehabilitation) returned to the wild; these otters joined wild otter
family groups in the area. Although long term monitoring was not possible, Karanambu staff
observed the rehabilitated otters repeatedly: 13 of these 16 giant otters were observed 2-4 years
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