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

Volume 16 Issue 2 Pages 58 - 110 (October 1999)

Abstracts

Re-Introduction Of Otters - Support Or Risk For Otter Conservation?
Pages 71 - 79 (Viewpoint)
Claus Reuther
Abstract
At the VIIth IOC, there was concern over the increasing number of reintroduction projects not following IUCN guidelines. All members of the OSG are asked to contribute to the discussion. This article refers to my experience with the Eurasian Otter, Lutra lutra. The guidelines, and the current situation of this species are discussed, concluding that in Europe, reintroductions do not fulfill IUCN guidelines. Otters are recovering naturally as the environment is cleaned up - we need to wait patiently for years if necessary. However, for this to happen, it is vital that areas where otter populations are strong should be protected, and money is better spent on this than on artificial reintroductions.
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Re-Introduction Of Otters - Support Or Risk For Otter Conservation?
Pages 80 - 86 (Viewpoint)
Addy W.J.J. de Jongh
Abstract
Otters decreased in numbers during the last through decades in many parts of Europe, with populations fragmenting or being extirpated, but this has been lately reversed through wetland improvement and so on. Before re-stocking or re-introducing otters, one has to be sure that the conditions for survival are adequate and that all the original causes for the decline or extinction of the population have been removed. All of the IUCN Guidelines for Re-introductions have to be followed.In many cases, releasing otters is not necessary at all as a natural influx of animals from neighbouring populations will soon follow after the former threats have been removed.In other areas, such as Holland, this could take more than 50 years because the nearest flourishing populations are so far away. Re-introductions help to establish more populations throughout Europe, securing the long-term survival of the entire population. Well-prepared and performed re-introductions give more impact to the otter’s function as a symbol. Re-introductions contribute to a higher bio-diversity. Re-introductions, and even preparations in that direction, provide economic benefits with respect to employment, cash flow and also environmental awareness. Under suitable restrictions, such as those already mentioned, I am in favour of re-introductions and, in some areas, restocking.
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Examination of Blood Samples of the Eurasian Otter (Lutra Lutra)
Pages 87 -92 (Article)
Christian König & Uschi König
Abstract:
Heparin and EDTA blood samples were analysed from 14 Eurasian otters. Reflotron and Vettest 8008 were used to identify ALB, ALPK, ALT, AMYL, AST, BUN, Ca, CK, CREA, GLU, Mg, BIL, GGT and CHOL. The electrolytes (Na, K and Cl) were measured by using VetLyte. The QBC haematology system gave a profile for HKT, Thrombo, Leuko, Gran and Lymph/Mono. These values were compared with those from dogs, cats and the North American river otter (Lutra canadensis). Several heparin parameters and a leucocytosis recorded in four individuals indicated that the otters were considerably stressed.
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Morphological Characteristics Of Sea Otter Enhydra Lutris L. (Carnivora, Mustelidae) Pelage And First Age Moult
Pages 93 - 102 (Article)
Sergey Vladimirovitsh Zagrebelny
Abstract:
Skin samples were taken from the midback and stomach of sea otters from embryos, new-born, one-month pups and adult sea otters up to 8 years old, from the Commander islands. The pale yellow coat of the embryos was shorter and less dense on the stomach than on any other part of the body. Two types of hair, guard hairs and underfur,were determined on the otters’ back. Generally, the fur of newborn and one-month old pups was still developing, and three different kinds of fur were noted - guard hairs, intermediate hairs and underfur. The cuticular scale pattern of juvenile guard hairs was of a mosaic type in the distal portion and lanceolate in the middle. The cuticle of the underfur and intermediate hairs was lanceolate shaped. No significant differences in embryo and new born pup hair parameters were found. Therefore it is assumed that embryo fur pelage consists of two hair-types with the taller and denser fur of older pups belonging to the juvenile generation. Two types of adult hairs were identified, 3-4 guard hairs and two underfur hairs. The cuticle of the guard hairs was mosaic in style at the blade and lanceolate at the base. The cuticular scale of underfur hairs was lanceolate throuhout their length. The juvenile pelage changed at 2 to 5 months of age, beginning at the chest and groin. At six days the moult progressed from the surface of the stomach to the back, ending on the head and the rump. The overall moult covered 80-90 % of the animals’ skin and concluded by the fourteenth day. Juvenile hairs remained on the head and rump until six months of age. Secondary moulting was noted in the animal living in the house after 55-60 days of observation. The new generation of definitive pelage was thinner and longer, and the moult followed the same order as the first moult. We argue that the first adult moult following the juvenile moult is an adaptation to extreme temperatures.
Contents | Full Text + Links | PDF (259 K)

Three Men In A Boat (To Say Nothing Of The Otter In Latvia)
Pages 103 - 108 (Article)
Janis Ozolins, Andreas Kranz and Ales Toman
Abstract
In the first half of this century, the otter Lutra lutra was regarded as 'nowhere numerous in Latvia but more common in the eastern part of the country than in the western'. Otters were rare in the whole East Baltic in the late 1970s. Field surveys carried out between 1986 and 1991 estimated the minimal population to be 4,000 otters. The aim of this study was to find out whether otters have increased in Latvia since the last survey 10 years ago, to find out what otters eat in late summer in a zone with low fish availability, whether otters occur along the Baltic coast, and whether they feed in the marine environment. A stable or possibly growing otter population was found. Along the coast, otter sign was only found in in the estuaries of small creeks, and little marine food was eaten. Such otters as were indicated were along rocky shores where kelp beds shelter fish, rather than the predominating sandy shores. Unlike the rest of Europe, fish were not the most important prey - amphibians were consumed in equal amounts, and there was a high proportion of insects and other non-fish food eaten. Only in eastern Poland are similar diet proportions found.
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Spraint Surveys And Sparsely Populated Otter Populations
Pages 109 - 111 (Report)
Paul Yoxon
Otters deposit spraint anointed with anal sac secretions in prominent sites in their territory. Otters have been shown to be able to distinguish individuals from their spraint, including distinguishing their own spraint from that of others. They may use these to signal resource use to other otters. Because they plainly have significance to the animals, when attempting to encourage otters back into an area, spraints should not be wholly removed for analysis as they may be of critical importance in encouraging an otter to stay.
Contents | Full Text + Links | PDF (30 K)

Eurasian Otter (Lutra lutra) Still Present in Syria
Pages 112 - 113 (Report)
Hélène Jacques
The author presents strong anecdotal evidence of presence of the Eurasian otter along the River Euphrates in Syria. Numbers, however, seem to have dropped considerably following irrigation schemes over the last 40 years.
Contents | Full Text + Links | PDF (96 K)

Behaviour of Otters in a Marine Coastal Habitat: Summary of a Work in Progress
Pages 114 - 117 (Report)
J. Scott Shannon
Since 1983, the author has studied 67 wild otters (Lontra canadensis) in Trinidad Bay, California, USA. The observations were made at short range (<100 m), and individuals were identified using a combination of facial and physical characteristincs. In Trinidad Bay, the otters normally form two social groups: one maternal family and one "Clan" of males. The most noticeable pattern in this population's social organisation was that adult males and adult females led largely sexually-segregated lives. Since 1986, I have studied the behavioural ontogeny of otters, chronicling the development of 6 litters (22 pups) by one mother, 4 litters (9 pups) by that mother's daughters, and 5 litters (7 pups) by a granddaughter. Here, the author summarises observations to date.
Contents | Full Text + Links | PDF (96 K)

The Otter Habitat Network Europe (OHNE) Project Has Been Started
Pages 118 - 121 (Report)
Claus Reuther
East and west of Central Europe there are thriving otter populations, but in Central Europe, populations are fragmented and isolated. This could lead to extinction in the middle range, and the development of subspecies on either side. Project OHNE, the Otter Habitat Network for Europe, aims to reverse this by reconnecting otter populations across Central Europe. The decline is due, not to overhunting, but to habitat destruction. The project therefore concentrates on restoration of otter habitats. The only chance for the survival of the otter is a management of riverine habitats and wetlands on a large spatial base. This means that we have to develop management or utilisation strategies for the landscape which allow man to satisfy his economic and social demands as well as allow the otter to survive. The proof of concept for the project is the revitalisation of the River Ise in Lower Saxony, subject to heavy pollution, canalisation and intensive use. Since 1987, led by Aktion Fischotterschutz, approximately 500 hectares of arable land have been transformed into extensive pastureland and more than 20 kilometres of riparian woodland and hedges have been planted, the costs being borne by the Federal Ministry of Environment, the Lower Saxony Ministry of Environment, the county of Gifhorn and the donors and sponsors of Aktion Fischotterschutz. The first phase of OHNE will be the identification of areas suitable as habitat corridors for dispersal or stepping stones for reinforcing locally low populations. The second phase will use this information to induce international, national and private organisations to include these data in planning and to take initiatives for regional otter habitat network programmes.
Contents | Full Text + Links | PDF (107 K)

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