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Home range characteristics and movement patterns of four female and six male polecats Mustela putorius Linnaeus, 1758 were studied in Luxembourg using radio- -telemetry. Home range size of polecats ranged from 42 to 428 ha with an average of 181 ha. The mean (± SE) home range size of males of (246 ± 45 ha) was significantly larger than that of females (84 ± 17 ha). Polecats concentrated 50% of their space use in only 15% of their home range possibly indicating a patchy .environment. Comparing our data with other studies in Europe, polecats seem to occupy approximately the same home range size (except in Switzerland) regardless of population density. Average distance traveled per night by males was 3.6 times greater than that of females. Also, seasonal variation in movements was observed in males but not in females.
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.
Stomach and intestine contents of 211 American mink Mustela vison Schreber, 1777 from two areas (Thy and Bornholm) in Denmark and stomach contents of 47 polecats M. putorius Linnaeus, 1758 from Thy were analysed. Sympatric mink (from Thy) preyed mostly on mammals (55% occurrence), followed by amphibians (36%), birds (33%) and fish (30%), whereas polecat preyed mostly on amphibians (87%) and mammals (34%), and only occasionally on birds (9%) and fish (6%). Allopatric mink (from Bornholm) preyed mostly on birds (50%), followed by mammals (42%), fish (25%) and amphibians (4%). With the possible exception of some amphibians, no endangered species were found in their diet. No differences were found in food composition between wild and escaped farm mink. The concern that mink in general might have a detrimental effect on its prey species and other mustelids in terms of food competition in Denmark may be unjustified. It cannot be ruled out, however, that mink may locally have a seriously negative effect on some specific prey species, and clearly, more data is needed on eg prey abundance and spring and summer mink diet, to make stronger conclusions.
Allozymic variation was surveyed in 21 European polecats Mustela putorius Linnaeus, 1758 from western France, using starch gel electrophoresis. Fourteen loci were success­fully examined and genetic variation was detected at 28.6% of the loci at the 0.05 level. Heterozygosity level averaged 0.082. European polecats from western France clearly showed significant levels of genetic variability. This result contrasts with previously reported analyses from Danish populations.
Polecats Mustela putorius Linnaeus, 1758 inhabiting a 4.5-km stretch of Orłówka stream in the Białowieża National Park, were studied by live-trapping in autumn and winter 1989 - 91. Ten polecats (6 males and 4 females) were captured. Every winter, from 1 to 3 polecats resided on the stream, and 1 to 3 transient polecats appeared on the river for short periods. None of the captured polecats persisted on the stream for three winters. The home ranges of resident males (estimated linearly along the stream) varied from 1 to 3.05 km, and those of females from 0.65 to 1.65 km. The home ranges of females were exclusive, but they could be completely overlapped by male home ranges. Radio-tracking of one resident male showed that its average daily movement distance was 1.1 km (range 0-2.1 km). During 19 days, it utilised 8 dens. Among polecats captured as pests by farmers in the village of Białowieża (n = 94) between 1960 and 1990, males predominated (sex ratio 1.7:1). Most individuals (54%) were captured in the cold season (November - February). The most likely cause of their appearance in the village was due to freezing of the rivers, which deprived the polecats of access to anurans and made them search for other food sources. From March till June, almost all the animals captured were males (of large body size). Their influx to the village might have resulted from their mating strategy: nomadism in search for receptive females. Polecats caught in autumn (males and females equally numerous) had low weights. They were the young dispersing from their natal ranges.
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.
Radiotracking of three couples of polecats Mustela putorius Linnaeus, 1758 in wetlands of western France showed that the monthly home ranges of male averaged 0.426 km2 and overlapped the females' ranges which were smaller (0.125 km2). Although the distribution of polecat's localizations in the three main habitats differed significantly between the male and the female, the seasonal overlap of habitat niches (Cjk) was considerable and varied from 0.727 to 0.894. The proportion of simultaneous localizations on the same square averaged 4% of monthly localizations while 96% of the localizations indicated solitary activity. Also, the duration of time occuring together was short: only 1.8 days per month on average. The observations suggested that the social organization of M. putorius was characterized by periodic variations of intra- specific tolerance between males and females which were probably influenced by hormonal factors during spring and by food availability during summer and autumn. A strong spatio-temporal segregation, however, determined a particularly individual exploitation of the space.
Lutra lutra, Mustela vison, M. putorius, M. erminea, M. nivalis, and the settle­ments of Castor fiber were surveyed along 170 km of rivers in Białowieża Primeval Forest (Poland and Belarus), the best preserved temperate lowland forest in Europe. The censused rivers varied from very small (1-5 m wide, < 1 m deep) to medium-sized (11-15 m wide, up to 3 m deep). Mustelids were counted by tracks left in snow. Mean index of abundance of otters was 2.2 inds/10 km of the river bank (range 0-5) and that of mink 4.6 inds/10 km (range 0-7.5). On average, 1.4 polecats/10 km were recorded (range 0-5). Otters and mink were most abundant on the medium-sized rivers and least numerous on very small ones. Polecats lived predominantly on very small rivers. Species structure of a predator guild varied with river size. On average, 5.1 stoats and 4.0 weasels were counted per 10 km of river bank. Stoats were twice as common along rivers with open marshy flood-plain as along rivers with forested valleys. On average, 2.9 beaver settlements were recorded per 10 km of river bank (range 0-5). Habitat niche overlaps were highest between otter and mink, and stoat and mink. The smallest overlaps were between the polecat and all other predators. Densities of mustelid predators and beavers in Białowieża Primeval Forest were similar to those in other fairly well preserved woodlands in Europe,
Food habits of European polecat Mustela putorius Linnaeus, 1758 and of American mink Mustela vison Schreber, 1777 are compared by analysis of scats collected from two radiotracked animals in a marsh habitat over a 5 month period. Both predators take a wide range of prey but polecat consumes more rodents and feeds upon am­phibians in spring, whereas mink mainly preys on fish and birds. Dietary overlap results from the common utilization of rodent prey. Both predators reduce competition by intensive exploitation of different resources and by segregation in the space use.
Amphibians were important prey to the European mink Mustela lutreola, the American mink M. vison, polecat M. putorius, river otter Lutra lutra, and badger Meles meles, and formed a minor component of the food taken by stoat Mustela erminea, weasel M. nivalis, and pine marten Martes martes. Mink and otter strongly selected for frogs Rana spp. and avoided toads Bufo spp. However, the common toad can be an important prey for semiaquatic mustelids under unfavourable feeding conditions. Toads (mainly Bufo bufo, and rarely B. viridis) also occurred in significant numbers in the diets of polecats and badgers, which seemed to prey on frogs and toads with no clear selection.
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