International Giant Otter Studbook Husbandry and Management
International Giant Otter Studbook Husbandry and Management
International Giant Otter Studbook Husbandry and Management
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It does not contain small rocks, gravel, or pebbles throughout. <strong>Otter</strong>s can effectively groom <strong>and</strong><br />
easily dig on/into the surface of this soil throughout their enclosures <strong>and</strong> they can dig deep into<br />
hillsides made of this furnishing. It can retain these qualities, with/without vegetation, <strong>and</strong><br />
function very effectively within a giant otter enclosure for many years with only some natural<br />
erosion of the hillsides over the years. At least one zoo (Brasilia Zoo) is known to have<br />
successfully used this soil for many years (see the paragraph below). These qualities therefore<br />
are those that a soil should possess to be considered an appropriate/effective soil type for<br />
Pteronura enclosures. This soil type can also support many underground dens that are naturally<br />
dug by giant otters <strong>and</strong> giant otters can successfully rear their cubs in the dens. (See Chapter 2<br />
Section 12 <strong>and</strong> below.) This substrate type is also therefore an optimal soil type for giant otter<br />
enclosures. Because the successful soil types used in some of the South American zoos are<br />
obviously not available for use in every enclosure, research should be conducted to identify<br />
appropriate <strong>and</strong> optimal soil types that can be provided in enclosures world-wide. (The<br />
functional soil types now used should be identified by scientific classification so their properties<br />
can be more closely studied <strong>and</strong> compared with other soils <strong>and</strong> so they can be recommended for<br />
use.) Soil types recommended should offer the same/similar qualities as those successful soils.<br />
Mixing soft s<strong>and</strong> with soft soil may help loosen a soil’s texture, although this technique has not<br />
been tried <strong>and</strong> it is unknown at this time if it would be appropriate for use.<br />
Non-ferric Red Latosol forms the approx. 2 m (6.56 ft) high (<strong>and</strong> higher) 40-45 o angle<br />
extensive hillsides <strong>and</strong> l<strong>and</strong> area within Brasilia Zoo’s expansive giant otter enclosures. Over<br />
the many years the hillsides at this institution are slowly reducing in size <strong>and</strong> degree of angle<br />
because of natural erosion <strong>and</strong> continual digging. The otters although, are still able to<br />
effectively use the hillsides for daily terrestrial activities, underground den building, <strong>and</strong> cubrearing.<br />
This soil remains loose in texture, even though it is exposed to full sun <strong>and</strong> hot<br />
Brazilian temperatures. When it is completely dry it easily breaks apart into tiny<br />
grains/particles that either are s<strong>and</strong> like-in appearance or are actually s<strong>and</strong> particles, as the soil<br />
contains s<strong>and</strong>. This quality seems to make it a very successful substrate for otters to groom <strong>and</strong><br />
dig on/into the surface <strong>and</strong> dig deep into. This is also probably the quality that makes the soil<br />
drain well. This soil type can have an approximately 53% clay content. The clay content may<br />
help prevent underground dens from caving in. (A soil must not have so much clay that water<br />
can not drain easily.)<br />
“Latosol: A soil class in the Brazilian Soil Classification System. Latosols are very deep, very<br />
well drained, homogeneous <strong>and</strong> highly weathered <strong>and</strong> leached soils. They tend to have medium<br />
to very high clay contents... These soils are similar to non-aquic Oxisols in soil taxonomy...<br />
Non-ferric Red Latosols are abundant all over the Cerrado [this area includes Brasilia]. Nonferric<br />
Red Latosols are quite variable in texture, which ranges from medium to very clayey.<br />
[They can have a] 53% clay content....Texture: [means] The proportion of s<strong>and</strong>, silt, <strong>and</strong> clay<br />
in a soil. Very clayey soils have more than 60% clay. Clayey soils have between 35 <strong>and</strong> 60%<br />
clay. Silty soils have more than 65% silt <strong>and</strong> s<strong>and</strong>y soils more than 70 or 85% s<strong>and</strong>. Medium<br />
textured soils have approximately equal amounts of s<strong>and</strong>, silt <strong>and</strong> clay.”<br />
(http://www.dcs.ufla.br/cerrado/cerrado2.htm internet site 2003).<br />
<strong>Giant</strong> otters found in the wild near Brasilia Zoo likely use/used this soil type (Latosol) for den<br />
building as well. In the wild giant otters will use a variety of soil types to dig their underground<br />
dens within. They will use soil that has a significant clay content as well as s<strong>and</strong>y soils <strong>and</strong><br />
other types. For example, “While s<strong>and</strong>y soils cave in more often they are still used <strong>and</strong> the dens<br />
[den] is repaired until it is ab<strong>and</strong>oned.” (Duplaix 1980).<br />
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