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American Mink (american + mink)
Selected AbstractsThe Smell of New Competitors: The Response of American Mink, Mustela vison, to the Odours of Otter, Lutra lutra and Polecat, M. putoriusETHOLOGY, Issue 5 2009Lauren A. Harrington We tested the response of wild American mink (an established alien species in the UK), to the odours of unfamiliar mink, European polecat and Eurasian otter. Polecats are similar in size and habits to mink, otters are larger than mink and a dominant competitor; both are native to the UK and both were absent during the original colonization by mink but are now undergoing natural population recoveries. The response of mink to experimental odours was assessed by counting the numbers of tracks (footprints) on rafts treated with anal gland secretions, and compared with response to a control raft, on two rivers in the Upper Thames valley, UK. Remote video showed that the number of tracks was positively correlated with the time that mink spent investigating an odour. We found that mink were attracted to the odours of both unfamiliar mink and polecats. There was little evidence that mink avoided the odour of otters. We suggest that, during an encounter with a polecat, mink may behave much as they would to a conspecific. We infer from the response of mink to the odour of otters, that, if mink do avoid otters, the mechanism of avoidance is likely to be complex, situation-dependent and perhaps affected by prior experience. [source] Modelling space use and dispersal of mammals in real landscapes: a tool for conservationJOURNAL OF BIOGEOGRAPHY, Issue 4 2003David W. Macdonald Abstract Aim To explore the usefulness of Spatially Explicit Population Models (SEPMs), incorporating dispersal, as tools for animal conservation, as illustrated by the contrasting cases of four British mammals. Methods For each of the four species (American mink, Mustela vison, pine marten, Martes martes, dormouse, Muscardinus avellanarius and water vole, Arvicola terrestris) a spatial dynamics model was developed based on an integrated geographical information system (GIS) population model that linked space use to the incidence of the species. Each model had, first, a GIS, which stored environmental, habitat and animal population information, and secondly, an individual-based population dynamics module, which simulated home range formation, individual life histories and dispersal within the GIS-held landscape. Results The four models illustrated different interactions between species life-history variables and the landscape, particularly with respect to dispersal. As water voles and dormice occupy home ranges that are small relative to blocks of their habitat, they were most effectively modelled in terms of the dynamics of local populations within habitat blocks but linked by dispersal. In contrast, because the home ranges of American mink and pine marten are large relative to blocks of habitat, they were best modelled as individuals moving through a landscape of more or less useful patches of habitat. For the water vole, the most significant predictors of population size were the carrying capacity of each habitat and the annual number of litters. For the dormouse, the likelihood of catastrophe and the upper limit to dispersal movement were the key variables determining persistence. Adult mortality and home-range size were the only significant partial correlates of total population size for the American mink. Adult mortality was also a significant correlate of total population size in the pine marten, as were litter size and juvenile mortality. In neither the marten nor the mink was dispersal distance a significant factor in determining their persistence in the landscape. Main conclusions At a landscape scale it is difficult to measure animal distributions directly and yet conservation planning often necessitates knowledge of where, and in what numbers, animals are found, and how their distributions will be affected by interventions. SEPMs offer a useful tool for predicting this, and for refining conservation plans before irreversible decisions are taken in practice. [source] Impact of released Eurasian otters on a population of American mink: a test using an experimental approachOIKOS, Issue 1 2004L. Bonesi Competition is considered to be a major evolutionary driving force within assemblages of related and morphologically similar species, but it is notoriously difficult to test and quantify especially amongst species that cannot be easily manipulated in a laboratory or in the field. By exploiting a re-introduction of Eurasian otters (Lutra lutra) in the Upper Thames catchment (UK) in 1999 we performed an experiment to test whether there was evidence of competition between otters and American mink (Mustela vison). Mink and otters are semi-aquatic mustelids belonging to the same guild. Otters are expected to be the dominant competitor because they are larger and better adapted at exploiting aquatic resources. Our hypothesis was that mink declines when the density of otters increases. We measured the effect of competition at the population level, by observing whether mink distribution and densities changed in an area of 1353 km2 in association with the arrival of its putative competitor. We estimated distribution and densities by means of sign surveys and trapping. The results showed that otters were associated with a significant and rapid reduction in the densities of mink, while mink occupancy remained approximately the same in an area of 2464 km2 that was used as a control. We observed that the spatial distribution of the mink population throughout its decline was influenced by the yearly cycle of mink activities, with areas being temporarily re-colonized during the dispersal season. Mink is an invasive species in the UK threatening the survival of some native species. Our findings suggest that the re-establishment of otter populations is likely to lead to a decline of mink that may, in turn, be beneficial to native species threatened by this invasive. [source] Competition between Eurasian otter Lutra lutra and American mink Mustela vison probed by niche shiftOIKOS, Issue 1 2004Laura Bonesi Interspecific competition is one of several constraints that might prevent an individual from maximising its energy intake. When an interspecific competitor is introduced, an individual is often forced to shift its diet according to the intensity of the competitive pressure. In this paper, we explore whether the introduced American mink (Mustela vison Schreber) shifts its diet when the density of its potential competitor, the Eurasian otter (Lutra lutra L.), is increased. We compared the diets of otter and mink at the same location but at two moments in time when the relative densities of these two species were different while controlling for the abundance of aquatic prey. Mink and otters are semi-aquatic mammals belonging to the same guild of mustelids and otters are expected to be the dominant competitor because they are larger and better at hunting underwater. The diets of otters and mink overlap to a great extent but while otters specialise mainly on aquatic prey, mink are able to exploit both aquatic and terrestrial prey. These observations prompted the hypothesis investigated in this work that at higher otter densities the diet of mink should change to include a higher proportion of terrestrial items. This hypothesis was supported by the data and at higher otter densities mink diet was observed to consist of a higher proportion of mammals and birds while fewer fish were present, although this pattern was present only in winter while no changes were observed in spring. Meanwhile the diet of otters remained basically unchanged. In the second part of the study, we investigated whether niche breadth and niche overlap between otter and mink changed at different otter densities. We found that niche overlap declined as the density of otters increased, in agreement with the prediction of habitat selection theory. [source] Immunocytological analysis of meiotic recombination in the American mink (Mustela vison)ANIMAL GENETICS, Issue 2 2009P. M. Borodin Summary Using immunolocalization of MLH1, a mismatch repair protein that marks crossover sites along synaptonemal complexes, we estimated the total length of the genetic map, the recombination rate and crossover distribution in the American mink (Mustela vison). We prepared spreads from 130 spermatocytes of five male minks and mapped 3320 MLH1 foci along 1820 bivalents. The total recombination length of the male mink genome, based on the mean number of MLH1 foci for all chromosomes, was 1327 cM. The overall recombination rate was estimated to be 0.48 cM/Mb. In all bivalents, we observed prominent peaks of MLH1 foci near the distal ends and a paucity of them near the centromeres. This indicates that genes located at proximal regions of the chromosomes should display much tighter genetic linkage than physically equidistant markers located near the telomeres. [source] | ||||||||||