Otter (Lutrinae) Care Manual - Association of Zoos and Aquariums

Association of Zoos and Aquariums 117
Otter (Lutrinae) Care Manual
Appendix G: Giant Otter Enclosure Design
Adapted excerpts from the “International Giant Otter Studbook Husbandry and Management Information
and Guidelines (2005)” for WAZA Website, and with added U.S. units of measurements (Sheila Sykes-
Gatz 2006).
The total minimum size enclosure for one giant otter pair should be at least 2,583ft 2 (240m 2 ) and
when indoor enclosures are needed, they should be a minimum of 807ft 2 (75m 2 ) of the total area. In
temperate climates, it is necessary that an outdoor enclosure (with or without heated outdoor water)
provides access to a heated indoor enclosure. Both indoor and outdoor enclosures require the same
recommended conditions (i.e., land to water ratios, substrates etc.). At least 2 dens (i.e., separable
rooms) to contain nest boxes/briefly hold animals should be provided, and at least 2-3 nest boxes (or
natural underground dens) are needed.
Providing the recommended land to water area ratios (i.e., enough land area), substrate types and
depths to cover all surfaces, and deep digging area sizes, is just as important as the need to provide a
swim area in all giant otter enclosures. These are among the most crucial husbandry provisions needed
to maintain giant otter physical and behavioral health, and they are also necessary to promote successful
pup-rearing and adjustment to new/unusual situations. To meet these needs, nearly the entire enclosure
surface area, including dens and nestboxes, must keep sufficiently dry, soft, and sanitary and otters need
to be able to effectively dig and groom throughout that entire area. The enclosure must also offer a
sufficient proportion of land, deep digging, and water area. The provisions in the two paragraphs below
are essential to providing these conditions.
Different enclosure sizes require different land to water area ratios. As enclosure sizes decrease
below 2,583ft² (240m²), proportionately increased land area sizes are needed. It is necessary to provide,
within each indoor and outdoor giant otter enclosure, at least the minimum percentage land area that the
following formula determines. Convert enclosure sizes to m 2 (ft 2 x 0.093 = m 2 ). For every 1m 2 that the
(indoor or outdoor) enclosure size is below 240m 2 , multiply that number (without the m² symbol) by 0.1,
then add the result to the number 60, and this resulting number is the minimum land area percentage (%)
that the (indoor or outdoor) enclosure requires. For example, a 1,615ft 2 (150m 2 ) enclosure requires a
minimum of 69% land area, and an 807ft 2 (75m 2 ) enclosure requires at least 76.5% land area. Enclosures
between 2,583-6,458ft 2 (240-600m 2 ) in size require at least 60% land area.
It is crucial that nearly the entire area of surfaces/substrates that giant otters are directly exposed to
are soft, natural, well-draining, not coarse, sufficiently dry and deep, and loose enough so that otters can
easily dig into them. It is necessary that every indoor and outdoor enclosure surface, including dens, is
nearly entirely covered with soft pebble-free sand or mulch (i.e., tree bark pieces only), at least 4-8" (10-
20cm) in depth, or deep soft loose soil with the needed qualities. The substrates used should not have
gravel, pebbles, rocks/stones