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We radiotracked 7 European mink Mustela lutreola Linnaeus, 1761 (5 males and 2 females), to determine their distribution, size and temporal changes of their home range in an area of southwestern Europe, where American mink M. vison was not established. Size of home ranges varied from 11 to 17 km along watercourses in males and were 0.6 and 3.6 km in females. Home ranges of males were larger than those found in previous studies. Most females captured (either radiotracked or not) were found within the home range of males. Males occupied adjoining river sections with minimal range overlap, suggesting an intrasexually exclusive spacing pattern for males. Each month males used new river stretches, mainly along tributaries; meanwhile they showed a steady use of their stem river section. Resting sites were mainly beneath dense brambles of Rubus patches located in the river bank.
The European minkMustela lutreola Linnaeus, 1761 and the European polecatMustela putorius Linnaeus, 1758 are related species sympatric in southwestern France. The European mink is rapidly disappearing whereas the polecat maintains good populations. Seasonal habitat use of both species was compared in the Landes de Gascogne region to identify if some vulnerability factors of the European mink were associated with habitats occupied by this mustelid. Potential habitats were mapped using a satellite picture and 12 main types of habitats were defined. Animal locations were recorded by radiotracking 9 European mink and 14 polecats from March 1996 to August 1999. Resting animals were located by triangulation, and, when possible, resting places were described. Animals in activity were tracked by continuous monitoring. Data collected revealed a strong preference of European mink for flooded habitats, particularly open marshes, flooded woodlands and moorlands. They seldom left the corridor of the riparian forest and their resting places were mainly in flooded environments, above ground (under herbs or bushes) or in cavities between tree roots. European polecats were less tightly linked to wetlands. Most of their locations were in the pine forests outside the valleys and their resting places were mainly in burrows. The strong specialisation of European mink in aquatic habitats is probably one of the main reasons for its decline because wetlands suffer drastic damages throughout all of its range. Maintaining adequate water levels is crucial for satisfying habitat requirements of mink.
Morphometric variation in 22 characters of 86 skulls of the European mink Mustela lutreola (Linnaeus, 1761), from the NW part of Russia, has been analysed. Stepwise discriminant analysis was used to estimate craniometric variables for sex determinations. Two characters (zygomatic breadth and interorbital width) are enough for the 96.5% correct classification. The male skull of M. lutreola is characterised by a relatively high neurocranium, widely arranged zygomatic arches, a wide rostrum, and by wider auditory bullae and higher mandibles. Sexual size dimorphism of M. lutreola is less than that of other similar-sized mustelids - Mustela putorius, M. eversmanii, M. sibirica, Neovison vison. The results are discussed in relation to the existing theories on sexual dimorphism in mustelids.
Reproduction of the American mink Mustela vison Schreber, 1777 population intro­duced to Belarus was studied in 1983 — 1992. Material consisted of 52 male genitalia, carcasses of 45 pregnant females, and observations of 19 litters with blind cubs and 31 litters with larger cubs, The study was conducted in two areas in northern Belarus: Rossony, where the decrease of mink numbers due to excessive trapping was recorded, and Gorodok, where the expansion of American mink in the presence of the native European mink Mustela lutreola was observed. Mating period of American mink lasted from mid February to mid April. Young were born from April till mid June. Litter size was on average 4.2 (blind cubs) and 3.3 in older cubs (> 2 months old). Repro­duction intensity on Drissa river and its tributaries was related to density. On average, 3.3 embryos per pregnanat female were found in 1-yr females and 4.3 in > 2-yr old females at the density of 13.3 mink/10 km of watercourse. In the low density population (2.8 mink/10 km due to overexploitation by hunters) reproduction intensity increased to an average of 4.2 embryos in 1-yr females and 6.0 in £ 2-yr females. During population decrease, percentage of young increased and the sex ratio became biased towards females. In an expanding population of American mink that had newly colonised Lovat river, the reproduction was very intense (7.3 - 7.6 embryos/female). The results show a great reproductive plasticity of American mink that obviously helped this species to successfully colonise new ranges after introduction.
The European mink (M. lutreola) and the American mink (M. vison) are riparian mustelids inhabiting Spain. During the last few decades, M. lutreola populations have declined almost everywhere, but, since being introduced in Europe, the American mink has become wide spread there. The present study presents the first comprehensive helminthological data of both mink species in Western Europe and analyses the possible cross-transmission of some pathogenic helminths between neighbouring Spanish populations of both mustelids. One hundred and forty specimens (28 M. lutreola and 112 M. vison) from several Spanish zones were analysed. A total of thirteen helminth species were found: Metorchis bilis, Parametorchis sp., Pseudamphistomum truncatum, Euryhelmis squamula and Apophallus donicus (Trematoda), Taenia martis and T. tenuicollis (Cestoda), Aonchotheca putorii, Strongyloides mustelorum, Molineus patens, Crenosoma melesi and Aelurostrongylus pridhami (Nematoda), and Centrorhynchus ninnii (Acanthocephala). The helminth fauna of M. lutreola was qualitatively and quantitatively richer than that of M. vison. This fact was particularly evident amongst digeneans with four species (M. bilis, Parametorchis sp., P. truncatum and A. donicus) exclusively present in M. lutreola. Twenty-five M. lutreola individuals were infected with parasitic worms (89.3%). In contrast, less than half (41.1%) of the American minks analysed were infected by helminths. The helminth fauna of both European and American minks in Spain are compared with those of both mustelids in Belarus, where another important population of M. lutreola is present. Also considered are some epidemiological and pathogenic aspects of the helminth fauna of both mink species that might act as regulatory factors over the Spanish population of M. lutreola.
The European minkMustela lutreola Linnaeus, 1761 and the European polecatMustela putorius Linnaeus, 1758 are sympatric in southwestern France. They are related species but the former is highly threatened whereas the latter maintains good populations. Nine European mink and 14 polecats were radiotracked in the Landes de Gascogne region to compare their space use and to identify appropriate conservation measures for the European mink. Resting animals were located once a day and active animals were tracked by continuous monitoring. European mink had linear home ranges whose sizes were larger than predicted by Johnson’s model (mean±SD=2971±1888 ha in males and 257±113 ha in females). They travelled long inter-day distances (1.4±1.9 km in males and 0.4±0.6 km in females). Polecats had home ranges of various shapes (linear, circular or combined) and their sizes were consistent with Johnson’s model (707±779 ha in males and 51±58 ha in females). They also had shorter inter-day distances than mink (0.7±0.9 km in males and 0.2±0.4 km in females). However male polecats had longer activity bouts than male mink. Thus European mink exhibit large movements between small and distant activity areas while polecats compensate for their smaller range by a higher activity in restricted areas. The behaviour of the European mink appears to be an adaptation to habitats scattered over linear ranges. This extensive use of space suggests that conservation of this endangered species cannot be achieved in the confinement of Europe’s natural reserves. Conservation plans should aim at maintaining high quality habitats along entire river networks and ensuring safe movements for the animals, preventing particularly the risk of collisions with vehicles.
In 1986-1997, diet composition of the native riparian mustelids: the otter Lutra lutra (Linnaeus, 1758), the European mink Mustela lutreola (Linnaeus, 1761), the polecat M. putorius (Linnaeus, 1758), and the naturalized one, the American mink M. uison (Schreber, 1777) was studied in relation to seasonal changes of the habitats (the Lovat river, NE Belarus). Amphibians, fish, crayfish, small mammals, and birds appeared the essential prey resources supporting the guild of riparian mustelids. In the river valleys, the two mink species and polecat were characterized by opportunistic feeding habits, whereas the otters specialised on fish. In spring and autumn, frogs were important prey to all mustelids studied. The trophic niches of the two mink species were wider than those of the otter and the polecat. In the seasonally changing environ­mental conditions, the American mink appeared a more opportunistic predator than the European mink. Food niches of the three native mustelids overlapped notably less with each other (Pianka's a from 0.24 to 0.70) than with the American mink (a from 0.60 to 0.89). The obtained data suggest that in river valley habitats the naturalized American mink may be a strong competitor for prey with the native riparian mustelids, especially the European mink and the polecat.
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