International Giant Otter Studbook Husbandry and Management

action be taken to resolve these problems and that all institutions/persons involved undertake
these goals and openly communicate and share information with the professional community.
“Hacking out is probably the best technique for release available, but it should be noted that this
is controversial to some, and survival rates are questionable due to lack of experience and lack
of exposure to diseases, among other problems.” (Burnette 1994). This is regardless of whether
the otter is released before or after it becomes sexually mature. It remains controversial to
some because it is thought that even with the best scientific techniques, otter caretakers cannot
prepare or teach the otter how to deal with all of the potentially hazardous situations or
challenging environmental conditions it may encounter in the wild. Caretakers can neither fully
present handreared otters with the real life exposure they would have had if reared in the wild,
nor can they fully substitute for the training and social interactions natural parents and siblings
would have provided. (In the wild giant otters do not leave the family group until they are two to
three years old and they are dependent on their family for survival until then.) Giant otters
already inhabiting the territory the releasee is destined for, may prove too great of competition
for the releasee (i.e. limiting denning and fishing areas, etc.) or they may kill the releasee.
Released otters may also be unable to find mates or establish family groups and being solitary
can make survival much more difficult. They also may not be successful at rearing their own
litters, without the first-hand experience of being reared by parents or helping to rear younger
siblings (as done in the wild). Whether the otter is already returned to the wild or it is exposed
to wild conditions during the rearing/hacking out/rehabilitation process, predators (i.e. caiman)
may kill the inexperienced otters or the otter may approach humans (i.e. because they have lost
their fear of humans) and this may result in their harm, death, or capture. During the hacking
out/rehabilitation process wild giant otters may also kill the inexperienced otters while they are
being exposed to conditions in the wild. (Of course, this is dependent on the type of method
that is used during hacking out/rearing.) Otters that are being hacked out/reared in conditions in
the wild or releasees, which are generally not used to exposure to a wide variety of different
diseases/pathogens, may be especially susceptible to contracting diseases which may cause their
death.
Unfortunately, reports have shown the combined mortality rate of handreared orphaned wild
giant otters that have been reared/rehabilitated/hacked out for release and those that were finally
fully released back into the wild have been very high (i.e. the majority did not survive) because
of some of the same problems as mentioned above. Most (either during the rearing/hacking
out/rehabilitation process for release or after final release) got killed by wild giant otters, people,
or caiman. Some attempts to finally release the giant otters have also been unsuccessful. It is
important to note that, from what is known, it is generally rare that orphaned handreared giant
otters have been released back into the wild and to date, the releases below are the only ones that
are known to have occurred or been attempted.
To date, the only known cases that have been published about giant otter re-introduction and
hacking out were in Colombia (Gomez, Jorgenson, & Valbuena 1999) and in Guyana at
Karanambu Ranch (McTurk & Spelman 2004). The report by Gomez et. al. (1999) included
very general notes on the hacking out procedure used. It is as follows. One orphaned wild otter
was handreared for 6 months and the other was handreared for one month before their release.
They were handreared for one month together and they were also released together. One animal
was 5.5 months old and the other 8 months old at the time of their release. The study concludes
that the release was successful and the authors (who carried out this project) determined it was a
success based on the observations of these two animals three times in a one month period after
their release. During these times, the two cubs were identified and the authors were “sure” that
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