International Giant Otter Studbook Husbandry and Management

substrates for most of his life (i.e. 11 years at that time). This otter had very little land area,
because of an unsuitable land to water ratio, and he was kept on all concrete surfaces. For the
following year and in other enclosures he was offered mostly hard surfaces (both with
appropriate land to water ratios). The remaining fourth otter had limited exposure to a small
digging pit and soft substrates that could not be dug into or no soft substrates for 4 years.
Appropriate land to water ratios were offered. In the following 7 years (11 years was his life
span at that time) no digging areas or soft substrates were offered. This animal was housed on
all concrete surfaces and a very small land area. (The aforementioned otters were housed in at
least 2 or more different institutions during their life times.) These otters obviously had no
sufficient area to carry out the full extent of their innate digging and grooming behaviors and in
some cases no opportunity to perform digging behaviors at all. They also, for most of their lives,
had no or little comfortable land area on which they could play and exercise. The frequency,
duration, and intensity of these behaviors were significantly and abnormally decreased as
compared to a healthy otter and the location where these behaviors were carried out within their
enclosures were very limited (e.g. to just small digging or grooming areas). They carried these
terrestrial behaviors out to a minimal degree or not at all. They spent much more of their
day in the water than on land (including their resting hours) and most of their water
activities were limited to swimming aimlessly or at times swim pacing (i.e. a stereotypical
behavior performed in the water). These animals also exhibited daily either some or all of the
following behaviors: nervousness, fear of change, tension, stress, depression, boredom,
frustration, and/or very dulled/lack of alertness, attentiveness, and curiosity. During
new/unusual situations and additionally for two otters during cub-rearing, abnormally elevated or
excessive levels of stress were exhibited and successful adjustment to these situations was
seriously compromised. (See Section 10 for detailed information on such occurrences).
Three of these four animals (the first 3 described) were first exposed to enclosures which offered
the recommended deep digging areas and “nearly appropriate” grooming and land areas at
approx. the latest ages that were reported above. I.e. “nearly appropriate” means that the
majority (rather than the entire or nearly all as recommended) of the land areas were covered
with soft loose substrates (mulch/sand). Although, eventually their enclosures were improved so
that they were offered digging, grooming, and land areas (i.e. appropriate substrates nearly
entirely covered all the land and floor areas) as recommended. The fourth animal was first
exposed to an enclosure that was appropriately furnished as recommended, but this only
occurred 5 months before the conclusion of this particular study. Appropriate land to water
ratios and other important natural enrichment furnishings (i.e. large logs both on land and in the
water, bamboo stands etc.) were also offered to all of these animals. After these animals were
first exposed to appropriate or nearly appropriate enclosure conditions and underwent an
“adjustment period”, they all dug, groomed, played and exercised on land with a moderate
degree of frequency, duration, and intensity as compared to a healthy otter. They also spent
much more of their day (including their resting hours) on land than in the water. They although
used the entire land area to carry out their terrestrial behaviors. The stereotypical swim pacing
was no longer performed and their other abnormal unhealthy behaviors either were significantly
reduced (i.e. aimless swimming etc.) or completely eliminated (i.e. very dulled/lack of alertness,
attentiveness, and curiosity; depression, nervousness etc.). Just with appropriate enclosure
conditions alone (i.e. appropriate substrates, land to water ratios, and deep digging areas) they
were able to make significant or full recovery from their mental and behavioral health
problems and abnormalities. (Either the animals were moved to a totally new enclosure or
only the conditions aforementioned were changed within the enclosure they had been living in.)
These recoveries were achieved within approx. a half a year to one year’s time. These animals
are still behaving in the same way, i.e. either for a couple/few years after the conclusion of this
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