IUCN/SCC Otter Specialist Group Bulletin
© IUCN/SCC Otter Specialist Group

Volume 18 Issue 1 Pages 1 - 53 (April 2001)

Abstracts

Monitoring the use of artificial log pile otter holts using hair analysis from bedding
Pages 6 - 11 (Article)
Danielle Cowell, Gavin Thomas, Geoff Liles, Adeline Bradshaw, Louise Midgley and Fred Slater 
Abstract
Nineteen, approximately ten year old log pile holts (LPH) in mid-Wales, UK, were dismantled prior to reconstruction and any bedding from couches removed for analysis. The plant material making up the bedding was identified and animal guard hairs contained within it were determined to species. The bedding material simply consisted of opportunistically available material with little evident selection. Hairs of cow and sheep were clearly brought in with the bedding but it is suggested that hairs of otter, badger, fox, dog, cat, American mink and polecat indicate use of the LPH by the species concerned. A possible pine marten record is also considered.
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Monitoring otter populations by DNA typing of spraints
Pages 12 - 19 (Article)
Hugh A.H. Jansman, Paul R.F.Chanin and John F. Dallas
Abstract
To monitor mammals by direct observation is often very difficult. Therefore a new technique based on DNA typing of droppings has been developed. DNA typing of otter spraints can potentially provide estimates of population size, home ranges, dispersal, genetic diversity and which species are present. This article gives a set of guidelines based on two feasibility studies on how to use the spraint DNA typing method. There are three main points. First, a sample of the study population must be typed to check that levels of genetic polymorphism are high enough for individual identification. Second, spraints must be collected and stored correctly because DNA extracted from spraints is typically of poor quality and quantity. Spraint collection should take place within 12 hours after deposition and before 10 a.m., and spraints should be stored at -20°C in a solution to stop DNA breakdown. Third, laboratory technique must be meticulous in carrying out repeat assays of the same sample and in avoiding contamination among samples. The results of the feasibility studies suggest that spraint DNA typing shows promise for monitoring of otter populations. Further progress will depend on achieving higher success rates, lower cost, and developing more highly variable microsatellites and species-specific PCR assays. DNA typing of endangered and poorly known otter species could provide important information on their distribution and status. We therefore recommend that skin, tissue or DNA samples from all endangered otter species be archived for future genetic analysis.
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Observations on the distribution and conservation status of the Neotropical river otter (Lontra longicaudis) in the coastal lagoons of the Uruguayan Atlantic basin and their main tributaries
Pages 20 - 27 (Report)
Ignacio Lacomba, Alvaro Soutullo and Carlos M. Prigioni
There are very few studies on Neotropical river otters (Lontra longicaudis) in Uruguay. However, the species is nowadays considered to be fairly common in the country. This paper reports on its distribution and current conservation status in the Uruguayan Atlantic basin. It provides some information on activity patterns, diet, and interactions with fishermen. The presence of otters was evaluated through interviews with fishermen and local people, and through field surveys in 1999 and 2000. Otter presence was recorded in every lagoon and tributary surveyed. Local people consider that Neotropical river otters are currently more abundant than they were 10 years ago. This recovery is probably the consequence of the ceasing of commercial hunting. Otters are both day and night active, though foraging takes place more during the night. All year round, otters are frequently seen in small groups, which may indicate that they are more social than generally thought. Most of the dietary items recorded were fish and crustaceans, but preying on mammals, birds, and reptiles were also recorded. Interactions of otters with fishermen go far beyond preying on fish trapped in nets. Local fishermen do not perceive these animals as competitors, but as sympathetic companions.
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Some results of the 1991 and 1999 otter (Lutra lutra) surveys in the River Ise catchment, Lower-Saxony, Germany
Pages 28 - 40 (Report)
Claus Reuther and Anja Roy
Abstract:
As part of a river revitalisation project aiming at the re-connection of two otter occurrences in north-central Germany two surveys have been carried out to document the distribution of the otter in this region in 1991 and in 1999. This paper contains some of the results referring to 226 identical survey sites investigated in both surveys. Within eight years the percentage of positive sites increased by nearly five times from 2.2% to 10.2% and the number of 10x10km squares of the UTM (Universal Transversal Mercator System) grid increased by more than three times from 4 to 14 out of 32. 99.1% of the survey sites were located at running waters and 89.7% were connected with bridges. Of the 23 signs of otters found in the second survey 65.2% were found under bridges. Nearly three fourths of the survey sites were located at running waters of a width of 5m and less. However, there seems to be a tendency for a higher portion for the waters of a width of 6-10m for all positive sites as well as for the positive sites under bridges.
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