International Giant Otter Studbook Husbandry and Management

Section 13
Den Construction
“Den” refers to an individual man-made room, usually small in size [e.g. 4 m² - 9m 2 ] (43.05 ft²
- 96.88 ft²) and constructed with concrete, wood, etc., where an otter has access to. A nestbox
can be placed or animals can be briefly held (i.e. for enclosure cleaning, etc.) in a den. Dens
are off-exhibit and they do not serve as a nestbox. Note: the term “underground den” should
not be confused with the term “den”. Within this manual an “underground den” is that which
is dug by an otter.
Sections 1, 2, and 5 describe the den locations and land and water area designs and
locations (esp. land to water ratios) as well as land substrates that are needed to keep the
dens dry. Also discussed are the substrates that are necessary within the dens. Section
10B describes the den locations and husbandry practices needed to isolate dens from
human disturbances during cub-rearing. The aforementioned provisions are among the
most important requirements necessary for the husbandry of giant otters and without
them serious health problems and problems during cub-rearing can occur. (See Sections 3
and 10 for the problems that can develop.) Section 10B also discusses locations and designs
needed for keeper and animal shift doors to dens to offer privacy from human disturbances.
Section 2C also discusses designs that can prevent land and floor substrates from blocking
keeper and animal shift door movement. Section 9 describes locations and designs for animal
shift doors to dens necessary to keep dens at appropriate temperatures and the temperatures that
are needed within dens.
Enclosures should have at least 2 to 4 dens where otters can be briefly held or separated
(i.e. for enclosure cleaning, etc.) or/and nestboxes can be placed (for otters to sleep and keep
cubs in). It is important that enclosures have dens in all situations, i.e. even when otters
require no indoor housing for cold temperatures and natural underground dens can be used for
cub-rearing. This is because when it is necessary to temporarily contain or separate otters from
each other or specific enclosure areas, it can be done easily and without harm or significant
stress to otters and zoo staff. Hence, with dens, husbandry and management procedures such as
enclosure maintenance, repair, daily cleaning and servicing, medical care, and
unfamiliar/temporarily separated otter introductions can be accomplished more easily and safely
than without dens. (Note: giant otters can be very dangerous and enclosures should be
designed with this in mind. Also, giant otters will become stressed when they are separated
from their group members, although separation by shifting is significantly less stressful and
much more safe than separation by netting, anesthetizing, etc..) When natural underground
dens are not available, a nestbox (esp. those made of wood) placed in a den will offer the otters
more isolation from human disturbances and presence during cub-rearing than if it is just placed
somewhere within the enclosure area. Nestboxes therefore should be placed within dens to
offer additional privacy. Providing multiple dens, each with nestboxes, offers parent’s rearing
litters an opportunity to choose which area they feel most comfortable and safer in. It is
important that parents feel that they can move their cubs to a safer feeling den/nestbox,
especially after a disturbance has occurred. (Note: natural underground dens [i.e. dens that the
otters dig themselves] provide a great amount of isolation in combination with an expansive
enclosure or an enclosure that is totally isolated. These den types are highly recommended and
important to promote successful cub-rearing.) Indoor enclosures, whether they are attached
to outdoor enclosures or not, must provide at least two or more off-exhibit dens in addition
to the indoor land area that is necessary for otters to carry out all living activities that are
too cold to do outdoors. (See Chapter 2 Section 1 Part C for the recommended minimum size
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