<strong>Association</strong> <strong>of</strong> <strong>Zoos</strong> <strong>and</strong> <strong>Aquariums</strong> 6 <strong>Otter</strong> (<strong>Lutrinae</strong>) <strong>Care</strong> <strong>Manual</strong> Natural History/Description: Asian small-clawed otter (Aonyx cinereus): This is one <strong>of</strong> five otter species found in Asia. It is one <strong>of</strong> the smallest <strong>of</strong> the world’s otters, rarely weighing more than 5kg. A gregarious species, it is <strong>of</strong>ten seen in large groups <strong>of</strong> up to 15 animals, <strong>and</strong> ex-situ population studies suggest that these groups are composed <strong>of</strong> an alpha breeding pair <strong>and</strong> their <strong>of</strong>fspring from successive litters. Asian small-clawed otters have unusual h<strong>and</strong>-like front paws with increased tactile sensitivity <strong>and</strong> reduced webbing, which they use to forage for their prey <strong>of</strong> crustaceans, mollusks, <strong>and</strong> small fish. Asian small-clawed otters are found from Palawan (Philippines) through Indonesia, Southeast Asia, southern China, <strong>and</strong> westwards throughout the Himalayan foothills <strong>of</strong> Bangladesh, Bhutan, <strong>and</strong> Nepal. A disjunctive population occurs in southern India (Foster-Turley et al. 1990). Listed on CITES as Appendix II (www.cites.org) <strong>and</strong> as Vulnerable by IUCN/SSC the population is considered to be decreasing. African (Cape) clawless otter (Aonyx capensis): The African clawless otter is one <strong>of</strong> four species <strong>of</strong> otters found in Africa. It is the third largest species <strong>of</strong> otter. Only the giant otter <strong>and</strong> sea otter are larger. Adults range in size from 1.15-1.5m (3.8-5ft), <strong>and</strong> weigh from 16-20kg (35.3-44.1lbs) (Foster-Turley et al. 1990). The African clawless otter has been reported as living in family groups including the male, female, <strong>and</strong> pups (Rowe-Rowe 1978), family groups consisting <strong>of</strong> the female <strong>and</strong> pups, or singly (Chanin 1985). The prevalent social grouping may vary with the habitat, which also likely influences the size <strong>and</strong> degree <strong>of</strong> overlap <strong>of</strong> home ranges. African clawless otters use their sensitive, non-webbed fingers to forage food, which consists primarily <strong>of</strong> fresh-water crabs, crayfish, <strong>and</strong> some fish. In some areas, this species is reported to occasionally raid near-by farms for young maize <strong>and</strong> cabbages (J.Reed-Smith, personal communication). This species is distributed from Ethiopia in the east to Senegal in the west <strong>and</strong> south to South Africa, with a distributional gap in the rain forest area <strong>of</strong> the Congo basin, where the Congo clawless otter is found (Rowe-Rowe 1991). The African clawless otter is found in both fresh water streams <strong>and</strong> rivers, <strong>and</strong> along marine coastlines in South Africa. Due to the infrequency <strong>of</strong> the holding <strong>and</strong> exhibition <strong>of</strong> the African clawless otter in zoos <strong>and</strong> aquariums, many <strong>of</strong> the st<strong>and</strong>ards set for this species are extrapolated from those set by the N.A. river otter <strong>and</strong> Asian small-clawed otter husb<strong>and</strong>ry manuals. Listed on CITES as Appendix II (www.cites.org). Giant otter (Pteronura brasiliensis): This single species in the genus Pteronura is one <strong>of</strong> four species <strong>of</strong> otter found in South America. The giant otter’s large size (1.5-2m, 4.9-6.6ft), weight (25-32kg, 55.1- 70.5lbs) (Duplaix 1980), highly social nature (multi-generational family groups), <strong>and</strong> critically endangered status make this species attractive to many facilities. However, their specific housing requirements <strong>and</strong> sensitivity to disturbances make them one <strong>of</strong> the more difficult otter species to hold successfully in zoos <strong>and</strong> aquariums. The diet <strong>of</strong> the giant otter is comprised almost completely <strong>of</strong> fish. Although originally found in Colombia, Venezuela, Guyana, French Guiana, eastern Ecuador, Peru, Brazil, Bolivia, Uruguay, Paraguay, Suriname <strong>and</strong> northeastern Argentina, only remnant populations <strong>of</strong> giant otter are currently found throughout its former range. It is mainly found in slow moving rivers <strong>and</strong> creeks within forests, lakes, ox-bow lakes, swamps, <strong>and</strong> marshes in the tropical lowl<strong>and</strong> areas <strong>of</strong> South America. With an estimated total population <strong>of</strong> only 1,000-5,000 individuals, the giant otter is considered highly vulnerable to extinction. It is classified as Endangered by the World Conservation Union (IUCN), as Endangered by the US Fish <strong>and</strong> Wildlife Service, <strong>and</strong> is listed on Appendix I <strong>of</strong> the Convention on International Trade in Endangered Species (CITES). Historically hunted for pelts, the species is now threatened by increased human colonization <strong>of</strong> tropical lowl<strong>and</strong> rainforests. Other threats include habitat destruction <strong>and</strong> degradation, over-fishing, illegal hunting, mining, <strong>and</strong> water <strong>and</strong> l<strong>and</strong> pollution. North American river otter (Lontra canadensis): The North American river otter is one <strong>of</strong> the four new world river otter species. There are at least seven subspecies <strong>of</strong> L. canadensis. Adults range in size from 1-1.53m (3.3-5ft) <strong>and</strong> weigh from 4.5->16kg (9.9-35.2lbs) (Ben-David et al. 2001a,b; Reed-Smith 2001). Although frequently solitary, except for female with pups, the North American river otter shows a great deal <strong>of</strong> social plasticity (particularly males), <strong>of</strong>ten forming groups <strong>of</strong> 8-15 or more animals in environments <strong>of</strong>fering abundant resources (Blundell et al. 2002a,b). All male groups <strong>of</strong> up to 15 individuals have been maintained successfully in zoos <strong>and</strong> aquariums (Ben-David et al. 2000). In the wild, males do not participate in pup rearing; in zoos <strong>and</strong> aquariums males can be reintroduced to the family group once the pups are swimming well <strong>and</strong> in general interact <strong>and</strong> play with the pups. Both sexes occupy linear shaped home ranges due to their affinity for the l<strong>and</strong>/water interface. Activity centers (e.g., latrines), located within
<strong>Association</strong> <strong>of</strong> <strong>Zoos</strong> <strong>and</strong> <strong>Aquariums</strong> 7 <strong>Otter</strong> (<strong>Lutrinae</strong>) <strong>Care</strong> <strong>Manual</strong> home ranges, are important for both sexes. During a latrine activity study in Pennsylvania, Stevens & Serfass (2008) documented that visiting otters spent 72.7% <strong>of</strong> their time there smelling <strong>and</strong> investigating, 10.9% marking, 10.6% traveling, 4.6% rolling <strong>and</strong> rubbing, <strong>and</strong>
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