IUCN/SSC Otter Specialist Group Bulletin

© IUCN/SCC Otter Specialist Group

Volume 33 Issue 1 (January 2016)

Abstracts

A First Record of Ticks in Free-Ranging Giant Otter (Pteronura brasiliensis) in the Brazilian Amazon
Pages 3 - 7 (Report)
Fernando César Weber Rosas, Tânia Mara Sicsu da Cruz, Sérgio Luis Gianizella, Claudiane dos Santos Ramalheira and Thiago Fernandes Martins
Studies of the biology and ecology of the giant otter (Pteronura brasiliensis) have increased considerably during the past few years. However, information on epidemiologic aspects of this species is still scarce in the literature. A series of helminthes were recorded parasitizing giant otters, but they were all endoparasites. To date, there is no record of ectoparasites reported for this species. In the present study, we report for the first time the occurrence of a tick nymph of the morphospecies Amblyomma cajennense sensu stricto (s.s.) attached to the lower right lip of a free-ranging giant otter. The location where the tick was attached suggests that other areas of the giant otter body far from the head would preclude hematophagy due to the amount of time otters spend in the water while swimming and feeding. Increased records of A. cajennense s.s. parasitizing different hosts in the Amazon basin will contribute to future molecular analysis and to a better taxonomic and geographic knowledge of this species of the Brazilian Amazon, as well as to a better knowledge of the epidemiologic aspects of the endangered giant otter.
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Otter (Lontra longicaudis) Spraint and Mucus Depositions: Early Ecological Insights into the Differences in Marking Site Selection and Implications for Monitoring Prey Availability
Pages 8 - 17 (Report)
Nathan James Roberts, Ryan Matthew Clark and Delyth Williams
Otters are not territorial in the classical sense of marking territory boundaries. Instead they mark key resource areas within the territory with faeces, or spraint, for olfactory communication. There is a high level of site fidelity in otter marking behaviour and the function of scent marks may explain their spatial distribution. Typically marking sites are in proximity to deep water which provides key resource areas for energy-efficient foraging. Occasionally spraint is laden with mucus, which may also be deposited in isolation without any faecal material. Any difference in the microhabitat variables predisposing site selection by otters with mucus present and absent in depositions has not yet been quantitatively investigated. This study serves as a primary exploration of these selective processes. Here we show that habitat selection by the Neotropical otter (Lontra longicaudis) is different when mucus is deposited at a site compared to when it is absent. The cause of mucus deposition has been suggested in other otter species to indicate reduced prey availability or reproductive state. Depositions here were associated with deep water as in other studies, and temporally, the relative abundance of those with mucus present was highest toward the end of the dry season when prey availability is assumed relatively low. Here we infer how the monitoring of mucus prevalence may be used as a valuable efficient indirect index of the status of otters and their prey. For species whose primary threats include reduced prey availability, such as the Neotropical otter, research attention to these aspects of behavioural ecology are particularly significant in applied conservation. Furthermore, research to validate indirect indices of prey availability and species-habitat interactions may extend to benefit recreational interests and broader human-wildlife conflict mitigation strategies.
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The Conservation Status Of Otters In Prek Toal Core Area, Tonle Sap Lake, Cambodia 
Pages 18 - 31 (Report)
Daniel Willcox, Sun Visal and Simon P. Mahood
The conservation status of otters in South-east Asia remains poorly known, because of a paucity of records for which certain identification can be confirmed. Otter populations in South-east Asia face a multitude of threats and are in decline; the identification and then protection of sites that support sizeable populations is a priority for their conservation. A rapid camera-trap survey targeted otter populations along one stream in Prek Toal Core Area, an area of flooded forest in the Tonle Sap Great Lake Cambodia. 172 camera-trap days over May to July 2014 produced a total of 34 notionally independent photographs of otters, of which 24 could be identified as Smooth-coated Otter and 4 as Hairy-nosed Otter. Although few other otter records exist for Cambodia, these data indicate that Prek Toal is at least a regionally important site for these species and of probable global significance for Hairy-nosed Otter. Protection of fish-breeding habitat and a large waterbird colony has perhaps benefitted the otter population at Prek Toal.
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The Perilous Voyage of Indian Himalayan ‘Ambassadors’ amidst Anthropogenic Pressures and changing Climatic Variables
Pages 33 - 36 (Short Communication)
Nishikant Gupta, J.A. Johnson, Kuppusamy Sivakumar and Vinod B. Mathur
Otters, the ambassadors of aquatic bodies play a vital ecological role by indicating the health of these threatened ecosystems. Three species of otters, (i.e. Smooth-coated, Oriental small-clawed, and the Eurasian) were historically widely distributed in the Indian Himalayan region. However, otters here are under severe anthropogenic pressures. Additionally, the changing climatic variables in the region could potentially affect these species. Despite the growing threats, few studies on the current status, population and distribution of Indian Himalayan otters have been previously conducted. This article highlights the urgent need for novel scientific and policy-oriented strategies to protect and conserve the otters in the region
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The Smooth-Coated Otter Lutrogale perspicillata (Mammalia: Mustelidae) in Singapore: Establishment and Expansion in Natural and Semi-Urban Environments
Pages 37 - 49 (Report)
Meryl Theng and N. Sivasothi
The smooth-coated otter Lutrogale perspicillata reappeared in Singapore in the mid-1990s after an apparent absence of three decades. No assessment of their status has been reported since. We compiled 370 sighting records from the literature and verified online reports and submissions between 1998 and 2014. The records revealed increasing numbers of individuals since the 1990's with breeding populations in the western and eastern Johor Straits on the north shore, and in South of Singapore. About half the records were from three localities: Sungei Buloh Wetland Reserve (16%), Pulau Ubin (14%) and Serangoon Reservoir (14%). In areas of frequent reports of otter presence, camera trapping and sign surveys were conducted to determine the status (transient, infrequent, newly resident, established resident). Thirteen spraint sites and three den sites were identified at four localities, two of which were along rivers dammed to form freshwater reservoirs. The smooth-coated otter is using partially disturbed environments along the Singapore coastline, and in increasingly human-disturbed sites. As the interface with humans continue to increase, the importance of habitat preservation and public communication is highlighted.
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The Eurasian Otter Lutra lutra an Afghanistan: A Review of the Sparse Available Information
Pages 50 - 53 (Review)
Stéphane Ostrowski
The status of the Eurasian Otter in Afghanistan is particularly poorly documented, reflecting in part the effects of the country’s turbulent history of recent decades on mammal survey. In the 1970’s the species was reported in all major rivers and streambeds in Afghanistan between 400 and 2,900 m asl. Because of the poor security conditions that render most of the species’s historical habitat inaccessible, surveys carried out by the Wildlife Conservation Society (WCS) could only confirm since 2007 its presence in the Wakhan district of Badakhshan province, in the northeastern corner of the country. Surveys of Kabul fur market carried out by WCS in 2006 confirmed the continued trading of the species and a decline in market supply compared to survey results from the 1960’s, possibly as a result of a decrease in population size. Since 2010, the Eurasian Otter is on the list of protected wildlife species in Afghanistan. Clarification of the species’s current natural distribution, population trend and threats is necessary before appropriate conservation measures, if needed, can be proposed.
Contents | Full Text + Links | PDF (151 KB)

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