Space use and habitat preferences of the invasive American mink (<Emphasis Type="Italic">Mustela vison</Emphasis>) in a Mediterranean area

Space use, intra-territorial habitat preferences, and factors affecting both were studied in an invading population of American mink, Mustela vison, in two rivers of a Mediterranean region of Spain. Average linear home range was 1.19 ± 0.73 km (±SD) and core area was 0.21 ± 0.08 km for resident males (n = 10); while for females (n = 5) they were 0.54 ± 0.14 and 0.19 ± 0.11 km, respectively. Overlapping between the home ranges of residents was low. In no case their core areas overlapped. Home ranges were small in comparison to other study areas and in general the resident minks were territorial. Linear home range length was related to individual weight and to the river. Weight had a positive effect indicating a potential body condition effect, while river may be showing a habitat quality effect. Habitat preferences were positively affected by the abundance of helophytic vegetation and negatively by the presence of human activity. Helophytic vegetation offers both food and refuges, while human activity may represent a potential danger. Percentage of captures was higher inside the core areas and was slightly influenced positively by abundance of helophytic vegetation. All this information should be considered when designing and implementing measures to control the expansion of American minks. We recommend keeping going with the trapping sessions but, given the results obtained, reducing the distance between traps down to 200 m to maximize capturability (i.e., about doubling the trapping effort), and, when available, placing them near helophytic vegetation. In the absence of helophytic vegetation, traps should be located near any kind of vegetation providing coverage for mink and far from human activity.     

黑柄炭角菌产生的DPPH自由基捕捉成分

对黑柄炭角菌深层发酵制品中的DPPH自由基捕捉成分进行研究。经硅胶柱层析、中压液相色谱顺相和反相分离、制备型高压液相色谱分离等一系列步骤 ,共获得相对纯度在85%以上 ,收量在 2mg以上的自由基捕捉物质 2 0个 ,对其中的B4 1 6进行了质谱、1H NMR、13C NMR、1H 13CHMBC、红外光谱等的测定 ,测得分子式为C10 H10 O4 ,推断它为 5,8二羟基 3 甲基 3,4二氢异香豆素。在 2 0 μmol L时 ,它的DPPH自由基捕捉活性为维生素C的 1 67倍 ,维生素E的 2 1倍。     

Microsatellite markers for the endangered European mink (Mustela lutreola) and closely related mustelids

The European mink (Mustela lutreola L., 1761) is an endangered carnivore species whose populations suffered a severe decline during the last century. The genotyping of eight polymorphic microsatellite loci revealed a relatively low number of alleles per locus (two to eight), as well as low levels of polymorphism (observed and expected heterozygosity values per locus were 0.49 and 0.54, respectively). Cross‐specific polymerase chain reaction amplifications were successful in seven closely related mustelid species suggesting that these loci may be useful not only for assessing genetic variability in European mink populations but also for determining potential hybridization events between M. lutreola and other mustelid species.     

The effects of mice on stoats in southern beech forests

Introduced stoats (Mustela erminea) are important invasive predators in southern beech (Nothofagus sp.) forests in New Zealand. In these forests, one of their primary prey species – introduced house mice (Mus musculus), fluctuate dramatically between years, driven by the irregular heavy seed‐fall (masting) of the beech trees. We examined the effects of mice on stoats in this system by comparing the weights, age structure and population densities of stoats caught on two large islands in Fiordland, New Zealand – one that has mice (Resolution Island) and one that does not (Secretary Island). On Resolution Island, the stoat population showed a history of recruitment spikes and troughs linked to beech masting, whereas the Secretary Island population had more constant recruitment, indicating that rodents are probably the primary cause for the ‘boom and bust’ population cycle of stoats in beech forests. Resolutions Island stoats were 10% heavier on average than Secretary Island stoats, supporting the hypothesis that the availability of larger prey (mice verses wētā) leads to larger stoats. Beech masting years on this island were also correlated with a higher weight for stoats born in the year of the masting event. The detailed demographic information on the stoat populations of these two islands supports previously suggested interactions among mice, stoats and beech masting. These interactions may have important consequences for the endemic species that interact with fluctuating populations of mice and stoats.     

Sex- and concentration-dependent effects of predator feces on seasonal regulation of body mass in the bank vole Clethrionomys glareolus

Increased perception of predation risk can cause changes in activity, feeding and reproductive behavior in a wide range of taxa. Many small mammals in the temperate zone exhibit fluctuations in body mass in response to changing photoperiod. Bank voles lose body mass in winter which they regain when photoperiod increases in the spring. To determine if predation risk affects seasonal changes in body mass (BM), bank voles were exposed to two concentrations (low: LC and high: HC) of weasel feces. Food intake (FI) and daily energy expenditure (DEE) were measured to establish if differences in body mass were due to adjustment in energy intake or expenditure. Fecal corticosterone (CORT) was measured to assess whether the voles had detected and responded to predator feces as a physiological stressor. Voles of both sexes had higher levels of fecal CORT in the groups exposed to weasel feces compared to controls. Voles responded to the predator feces in a sex- and concentration-dependent manner. Males responded to LC feces by gaining less mass following the change in photoperiod. This was mediated by reduced FI and higher DEE. Female voles also gained less BM in response to HC feces, but increased both FI and DEE. We hypothesize that males may gain a short-term advantage by lowering BM in response to predation risk, which may be regained without affecting reproductive success. The consequences of mass loss in females may be more significant as this may delay the onset of breeding or reduce the size or number of young, thereby negatively affecting breeding success.     

Identification of a tyrosinase (TYR) exon 4 deletion in albino ferrets (Mustela putorius furo)

Albinism is due to a lack of pigmentation in hair, skin and eye, and has been shown to occur in several animal species. Mutations of the tyrosinase (TYR) gene account for albinism in domestic cats, rabbits, cattle, mice and rats. In this study, we demonstrate that a TYR mutation accounts for albinism in the ferret (Mustela putorius furo). The coding sequence of the five exons of TYR was determined in genomic DNA from wild-type pigmented 'sable' coloured and albino ferrets. It was not possible to amplify TYR exon 4 in albino ferrets originating from different breeds. The deletion of exon 4 in albino ferrets was confirmed by Southern blot hybridization of genomic DNA from albino and pigmented ferrets. This is the first report of a deletion of a TYR exon in a non-human mammal.     

The first linkage map of the American mink (Mustela vison)

Described herein, the first microsatellite linkage map for the American mink consists of 85 microsatellite markers resolved into 17 linkage groups. The map was constructed using 92 F(1) progeny from five sire families created by crossing mink with different colour types. The linkage groups ranged from 0 to 137 cM. These linkage groups were assigned to 12 of the 14 mink autosomes using a somatic cell hybrid panel. The total map covered 690 sex-averaged Kosambi units with an average marker spacing of 8 cM. This map will facilitate further genetic mapping of monogenic characters and QTL.     

黄鼬(Mustela sibirica)体型大小的性二型及地理变异

本文报道黄鼬体型大小的性二型及其与地理变异的关系。个体大小的性二型现象很可能与繁殖行为有关,许多在繁殖季节有争偶行为的一雄多雌兽类,雄性都有较大的个体。     

艾虎对不同猎物的选择性

在室内条件下,将高原鼢鼠(Myospalaxbaileyi)、高原鼠兔(Ochotonacurzoniae)和根田鼠(Microtusoeconomus)作为艾虎(Mustelaeversmanni)的猎物选择对象,研究艾虎对猎物的选择性及艾虎捕杀猎物的行为时间分配。实验结果表明:艾虎对三种猎物的搜寻时间和搜寻频次基本一致,在搜寻猎物的过程中并非已知洞道系统中所存在的食物信息,是一种机会主义的捕食者;艾虎除了具有典型鼬科动物捕杀猎物的方法外,能够根据猎物的大小、活动性和反捕食能力采用不同的捕杀方法,在捕杀猎物的过程中首先捕杀高原鼢鼠,其致死部位全部为头部,其次捕杀高原鼠兔,其致死部位除了头部外,明显增加了颈部的比例,最后捕杀根田鼠,其致死部位主要是头部和胸部;艾虎在捕杀猎物的过程中,追击根田鼠的时间最多,追击鼢鼠的时间最少,而用于捕杀根田鼠的时间最少,用于捕杀鼢鼠的时间最多,艾虎捕杀高原鼠兔后单位时间内获得的能量值最大,其次为捕杀高原鼢鼠,而捕杀根田鼠后单位时间内活动的能量值最小。因此,在室内条件下艾虎对猎物的选择性主要依赖于其本身处理猎物的行为时间分配和猎物的反捕食行为,使单位时间内获得的能量值最大.     

Field trials of slow‐release synthetic lures for stoats (Mustela erminea) and ferrets (M. furo)

Abstract

Experimental field trials were used to compare the attractiveness to stoats (Mustela erminea) and ferrets (M. furo) of traps set with either a synthetic scent lure or with fresh food bait. One lure, containing 2‐n‐propylthietane, effectively attracted as many ferrets as did rabbit meat bait. Fewer stoats were caught with this lure than with egg bait. Made up in a slow‐release formulation in “plastic rope”, the lure remained attractive to ferrets for at least 2 weeks under sunny field conditions. Traps containing a second lure, 3‐n‐propyl‐l,2‐dithiolane, were less successful at catching both mustelid species than those containing fresh food baits. The scent lures were not attractive to non‐target species, but neither did they deter some species.