Caring for Selected Otter Species (Asian small-clawed, Cape ...

public access as a secure zone for the animals. Sykes-Gatz (2005) and Hancocks (1980) are two of the many
resources available with information on naturalizing older exhibits.
All pool shorelines should be provided with lounging logs, shaded rest areas, and sandy banks to be used
as latrine sites. Large flat/sloping rocks and logs can be used along the shoreline to hold back the substrate as well
as provide good sunning areas.
A variety of substrates should be incorporated into otter exhibits. These substrates include: grass, mulch,
sand, clay, soil, rocks, boulders, pebbles, leaves, bark, concrete, and gunite (the latter two are not recommended
and should be limited to small areas, or should be covered with soft pebble-free sand or tree bark mulch when
their use is unavoidable). Exhibits with artificial substrates should offer areas of grass, dirt, sand, pebbles, etc. for
exploration and adequate grooming. Hard-pack soils, abrasive sands, and sharp rocks should not be used in otter
exhibits. Recent research into the structure of sea otter (E. lutris) and river otter (L. canadensis) hair structure
shows guard hairs can suffer damage (Weisel et al. 2005). While unclear at this time, it is possible that extensive
damage to guard hairs can impact the insulative ability of the otter’s coat. Problems with chronically wet surface
areas or overexposure to hard surfaces should be addressed immediately to prevent injuries to the animals (e.g.,
foot pad abrasions) or health issues (e.g., fungal infections) from developing.
All exhibits should offer bedding material; products used successfully include: grasses, leaves, hay, straw,
wood wool, sedges, pine needles, towels, burlap bags, indoor/outdoor carpeting, natural fiber mats, and wood
shavings (Reed-Smith 2001). Some facilities have successfully used fleece and blankets (Ben-David et al. 2000,
2001a,b; J. Reed-Smith, personal experience). However, as with all bedding, these should be monitored to ensure
the otters are not chewing on, or eating them. If animals are chewing on these items, they should be removed
immediately. Some wood shavings (from conifers) contain residues that can strip the water proofing from the coat
of semi-aquatic species, and/or may cause sneezing. Cedar contains aromatic phenols that are irritating to the skin
and respiratory system. Several studies indicated that close, chronic contact with cedar shavings contributed to
infant mortality (Burkhart & Robinson 1978), respiratory disease (Ayars et al. 1989), and liver damage (Vesell 1967)
in rodents. The impact of these products on otters is unknown; if used, caution should be exercised.
Some facilities use paper products such as shredded paper, cardboard boxes, paper bags, and cardboard
rolls. These products should be monitored carefully to ensure the animals are not ingesting them or taking them in
the water where they could become plastered over an animal’s mouth and nose, or become impacted in their
teeth. In most cases using these products with otters is not advised.
Indoor/outdoor carpeting and natural fiber mats also have been used for the animals to roll and groom
themselves on in concrete holding areas. All materials used for bedding should be monitored in case an animal
consumes them excessively, or in the case of towels, etc., shreds or eats them. ‘Wood wool’ sticks to fish or other
moist foods, and so should not be used near feeding areas to prevent its ingestion. When it is used in nest boxes,
caution should be exercised if any females become pregnant as pups can become entangled in it.
L. canadensis: Typically L. canadensis shed their under-fur between May and August (This “…under-fur
produces a dense, matted, felt-like layer, which forms an efficient insulating layer by trapping air next to the
skin…’[Dunstone 1998]), and replace their guard hair between August and November (northern latitudes, there
may be some variation in timing at southern latitudes) (Ben-David et al. 2000; J.Reed-Smith, personal observation).
Animals’ health requires ample grooming opportunities and surfaces on which they can rub to prevent matting,
and aid in this annual coat replacement process. Grooming and drying opportunities also are important for the
maintenance of healthy foot condition, with damp or excessively humid conditions leading to footpad abrasions.
Sensory barriers
Visual barriers are important to allow animals to avoid one another, when necessary. All individuals,
particularly paired otters, will go through times when they exhibit a tendency to stay by themselves. Vegetation,
exhibit topography, denning sites, and deadfall should be strategically placed to allow for this. While there is no
evidence that low level background noise is disruptive to otters, loud noises can be frightening to them, and highpitched,
long-term noise should be avoided.
Otters can be odiferous; facilities with indoor exhibits may want to provide olfactory barriers for the
comfort of the viewing public. If exhibiting more than one breeding otter group, or permanently separating
animals from a group and housing them within the same institution, it may be very important to have visual,
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