International Giant Otter Studbook Husbandry and Management

malfunctions, due to severe inbreeding, were likely to have prevented the survival of all of the
cubs born at the fourth institution, Dortmund Zoo (Osmann & Wisser 2001). (This institution
only had one breeding pair and this pair had 28 cubs/13 litters born from 1995-2002. No cub
born from this pair, whether parent-reared or hand-reared (8 were handreared), survived beyond
3 months of age. It is expected that this breeding pair will never reproduce successfully and that
this problem likely resulted from three generations of inbreeding. These conclusions were
based on necropsies (i.e. where thyroid glands were closely examined and found to be nonfunctioning
or malfunctioning) and similar cub symptoms. Cub deaths, mostly very young
cubs, also resulted when the parents ate or severely abused them (esp. soon after their birth)
when seclusion was not offered during previous litters. See Chapter 5 Section 5 for more
information on this problem.)
From 1998 to 2002, all four of the aforementioned institutions provided their parents with
privacy from human disturbances and presence during cub-rearing through their management
methods and/or “exhibit design” alone. [Note: Museu Goeldi (Belem) provided privacy through
their management methods and Criatorio Crocodilo Safari (also referred to as Belem) provided
privacy through their “exhibit design”. ] Cali Zoo although did not use this method for three of
their litters (7 cubs total) during this time and their zoo staff believed that the seven very young
cubs in these litters were eaten by their parents because of human disturbances (Corredor, pers.
comm.). These cubs accounted for 17.5% of the total number of cubs born between 1998-2002.
Of the total number of cubs that were born live at all four of these institutions between 1998-
2002, 40 % were successfully reared. (This is a 60% cub mortality rate.) This shows a
significant increase in the success of cub-rearing compared to the success rate found from 1968
to 1997. This seems to be because more cubs were born with the provision of privacy than
during the last study. It is also important to note that the cubs born live at Dortmund (17 cubs)
accounted for 42.5% of all the cubs born between 1998-2002 and this is a significant proportion
of the total births. If these cubs were not included within the statistics, it would show that all of
the cubs born between 1998-2002 and that were offered privacy lived to one year or older (i.e.
100% were successfully reared).
In a 34 year period, between 1968 and 2002, nine institutions worldwide reported giant otter
births. A total of 82 litters were born and a total 217 cubs were born live and registered. Of
these 217 cubs, only 45 (or 20.7%) are known to have survived to one year old or older. (This
is a 79.3% mortality rate.) It is important to note that a greater number of cubs could have been
born. This suspicion is based on the theory that not all litters have been detected. No zoo has
ever reared their giant otter cubs successfully unless privacy was offered during cubrearing.
Even parents that had already reared one or more litters successfully with
seclusion, did not rear their following litters successfully unless they were offered this
method. (I.e. without this method they ate or neglected their cubs and litter loss resulted
because of disturbances to the parents.) Parque del Este Zoo at Caracas was the first zoo in the
world to report a giant otter birth and this occurred in 1968. Until 2000, there were no known
captive-born cubs that have been successfully reared by parents which both had been captive
born. Since 2000, at Brasilia Zoo, eight cubs were born from such a pair.
When indoor and/or outdoor enclosure land to water ratios offered smaller land proportions than
recommended or/and land/floor surfaces were not nearly entirely covered with soft loose natural
substrates (including appropriate types, qualities, and depths) or provided with sufficient size
deep digging areas as recommended, the following has occurred. Physical and
mental/behavioral health problems and/or abnormalities have occurred not only during typical
daily circumstances, but also during cub-rearing. (See Chapter 2 Sections 3B & 10 and Section
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