International Giant Otter Studbook Husbandry and Management

play, exercise etc. on. Note: when a container of mulch is just acquired many bark pieces will
often be significantly larger than 4 cm x 10 cm in size, although these individual pieces will
break down more quickly than the smaller size pieces and they therefore should not cause a
problem. Mulch bark pieces 10cm x 4cm in size are therefore most highly recommended
over smaller or larger size mulch. Sand used in children’s sand play boxes or other soft sands
should be provided. Abrasive or sharp sand (e.g. builder’s sand that is used for construction) and
sand or mulch with any kind of pebbles, gravel, small rocks or larger rocks throughout must not
be used.
If minimum substrate depths and substrate quality (esp. quality of mulch) are not maintained
inefficiencies/problems can develop. Water naturally drains through mulch and soft sand esp.
well. These land furnishings therefore, used in both indoor and outdoor enclosures and over
most all surface types (see the introduction above) dry easily and quickly if they are maintained
properly. Substrate depths shallower than 10 cm to 20 cm (4” to 8”) will not dry as easily or
quickly, they can remain wet/very damp, otters cannot effectively/will not use them esp. for
grooming and digging, and health problems can develop. When mulch breaks and packs
down, i.e. bark pieces have broken into small pieces and they pack tightly together, the same
problems will occur. (See Section 3 below for the health problems that can develop.) Giant
otters cannot effectively/will not use very damp or wet substrates, shallow substrates (as
described), or broken down mulch to groom and dig in.
In the aforementioned cases, new furnishings simply need to be added to restore the substrates
efficacy and quality and to provide appropriate depths. In both indoor and outdoor enclosures
mulch and sand last long periods of time (i.e. many months to a year depending on the size of
the area) before new substrate needs to be added on top of the existing layer. Leaving the
existing substrates will help increase substrate depths. Unless the existing substrates are in a
very small well-used area, they do not need to be removed, only added to. Mulch might need to
be removed and then replaced (with totally new mulch) in very small well-used areas, i.e. such as
small dens around 3 m² - 4 m 2 (32.29 ft² - 43.05 ft 2 ), one or two times per year. When necessary
although, such as during cub-rearing, it can remain unserviced for longer periods. Such areas
although may only just need to be added to. Mulch can pack and/or break down more quickly in
very small well-used areas. Small well-used areas or areas adjacent to water, may require depths
deeper than the 10 cm (4”) to 20 cm (8”) minimum recommended. The deeper the mulch or
sand, the drier it will remain. Substrate depths and quality must be monitored.
Mulch kept in very dry areas, e.g. indoors, should be lightly misted on its surface with
water from a hose (except for during cub-rearing). Misting only needs to be carried out for
several seconds once daily. This will help keep mulch from becoming overly-dry and breaking
up and dusting. The mulch should only be misted long enough so that it becomes slightly damp,
not wet, which is counter-productive. Mulch that does not become too dry, does not need to be
misted.
Specific Soil Types and Husbandry Techniques
Unfortunately, because few studies exist, recommendations for specific (i.e. by scientific
classification) soil types that would be appropriate/effective or optimal for use in giant otter
enclosures are limited at this time. (The introduction above describes the qualities that soil
must possess and the qualities that are inappropriate/harmful.) At present, the only soil type
that can be recommended for use is Non-Ferric Red Latosol and it is found in Brazil, although
most of the soils found in nature in South America are likely appropriate for use. Non-ferric
Red Latosol dries easily, is well-draining, soft, and loose in texture, and it does not erode easily.
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