International Giant Otter Studbook Husbandry and Management

Within this manual “underground den” and “natural underground den” refer to a den that
has been dug by the otters themselves (i.e. dug into natural substrates and underground) and the
otters can use this den to sleep/rest and keep cubs in.
Sections 1, 2, and 5 describe the land and water area designs and locations (esp. land to
water ratios), land substrates, as well as hill/bank locations for natural underground dens,
that are needed to keep the hills/banks and underground dens dry. Also discussed are the
soil substrate qualities and types and hill/bank designs that are needed to construct areas
for natural underground dens to be dug. Section 10B describes the hill/bank locations and
husbandry practices needed to isolate underground 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.
The provision of hillsides/banks within outdoor enclosures, with the designs and substrates
recommended, would encourage and enable giant otters to carry out their natural
behavior of digging underground dens to sleep and rear their cubs in. These natural
underground dens, that help isolate parents rearing cubs from human disturbances and presence,
are very important to aid successful cub-rearing in captivity (Duplaix-Hall 1975; Louzada
da Silva, pers. comm. 1998, Genealogical Meeting…in Brazil” 1998, Sykes 1998/2002; Sykes-
Gatz 2001). (Section 10 describes how these dens provide privacy.) Hillsides/banks also help
keep land areas dry (by providing water drainage areas) and add variety to an enclosure. They
as well provide an optimal source for physical and behavioral stimulation/enrichment. For these
reasons, this provision is highly recommended. The inclusion of other types of varying terrain
can provide some variety.
Wild Pteronura use the multiple underground dens that they dig within their vast territory, to
rear cubs and sleep in. When given the appropriate conditions (i.e. substrate types and
qualities and hill designs as recommended), captive Pteronura can also dig many deep
underground dens throughout the expanse of the hillsides/banks provided (e.g. extensive
hillsides) and use them for the same purposes. E.g. captive Pteronura have dug many
underground dens throughout a 500 m 2 [5,382 ft²] land area composed of hills that have the
recommended designs and substrate furnishings (see below). The expanse of the hillside/bank
area provided should be as large as possible to accommodate this behavior. (See Section 2
for information on the minimum size area of hills/banks that are needed when hills are used for
deep digging and/or underground den building areas, as well as information on optimal sizes.)
It is important although that plentiful level land area is offered, with the recommended
substrates, for otters to use when hills are provided. E.g. level land can be located at the top
of the hills, along the water’s edge, or/and elsewhere within outdoor enclosures and some areas
can also be furnished with deep soft sand for variety in digging substrate. Otters in the wild will
form multiple campsites on level ground throughout their territory (Duplaix 1980). (“...sites are
usually above the high tide and high water level...The elevation is 50 cm to 2.5 m above the
slack water line...” Low sloping banks are preferred.) Campsites are large level land areas
where terrestrial/living activities, such as eating, marking, drying, grooming, playing and resting
are carried out. These sites can also be located next to/over top of their underground dens, but
they are not always located in the same area as their dens. A number of sites can be visited and
used several times within a few days (Duplaix 1980). “...the average size [site] on three
different rivers was remarkably similar : Upper Coesewijne river 8.12 m x 6.81m [26.64 ft x
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