International Giant Otter Studbook Husbandry and Management

underground dens in this expansive exhibit and they were sometimes not known about until the
parents moved the cubs (i.e. when cubs were more than one month old) from the underground
den. It could be possible that cubs were born from this breeding pair during the two years the
pair raised their offspring, but they were not detected. If litters were born, they might have had
similar problems as those experienced at Hagenbeck Tierpark, because of the competition the
older siblings might have created. (See the alternative theory in the following paragraph.)
The cubs that were born (5 cubs in total) when their siblings turned 2 years old, were
reared by the entire family in a healthy natural manner, until the young cubs turned 4
months old (at which time the 2 year old siblings were removed from the enclosure) (Brasilia
Zoo, pers. comm., 2002). The three female older siblings helped to care for their younger
siblings, as they would do in the wild. It could be possible that because the older siblings
reached a mature age, they presented no competition for the mother’s milk and they were old
enough to more carefully handle possible younger siblings, because of their own experiences of
being cared for. In the event that litters were not detected during those two years simply
because litters were not born, it might be possible that the older siblings could have successfully
cared for hypothetical younger siblings. They might hypothetically have been successful
because of the expansive enclosure that offers a simulating and challenging environment. This
might have been enough to occupy their attentions so that they would not excessively play with
or overly focus on their hypothetical younger siblings as play toys for lack of better enrichment.
"In Manu National Park, Peru, in 2001 a giant otter family gave birth to two
litters spaced approx. six months apart. One cub of the first litter survived and
remained with the family during the successful rearing of the second litter.”
(Groenendijk pers. comm. 2003)
Many factors can affect how successfully juvenile and sub-adult siblings (and mature
siblings) are able to co-exist with and help care for their younger siblings, this therefore
affects cub-rearing success. These factors include the quality, size, design, and furnishings of
the indoor and outdoor enclosures (see Parts A-B above for an explanation of these factors).
They also include individual otter personality and history (e.g. physical and behavioral
problems), the degree of experience that parents and offspring had with rearing cubs, family
social structure, and the age of the older siblings at the time of the new litter birth. The amount
of visual and acoustic privacy/isolation available, the duration, intensity, frequency, and
familiarity of disturbances, and husbandry and management practices are also factors as well as
the other issues discussed within this section. In an ideal situation, it would be advantageous for
cubs to remain with their family group until they are two years old. Helping to replicate the
natural social structure found in the wild would provide the maturing cubs and parents with a
more natural, enriched, and stimulating environment. If new litters were born, this would allow
otters from previous litters to gain experience helping to rear cubs, which would be highly
beneficial towards their own parenting skills later on in life. When cubs reached sexually
maturity (i.e. at 2 years old), they then could be mated with non-related individuals to form a
breeding pair. Although, because the situation of giant otters in captivity is so critical, cubrearing
success has been so poor, there are very limited experiences with these matters,
and many zoos do not have ideal situations, little chance should be taken for
experimentation.
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