排序方式: 共有6条查询结果,搜索用时 15 毫秒
1
1.
P. I. Webb J. D. Skinner 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1996,166(5):325-330
We determined the effect of food availability (presence/absence) and ambient temperature (25/10°C) on daily energy expenditure
and the use of activity and torpor in summer-acclimated captiveGraphiurus murinus. Daily energy expenditure declined logarithmically with duration of food deprivation at a mean rate of 11 and 31% per day
at 25 and 10°C, respectively. The incidence of torpor in the presence of food at 25°C was low (one in seven individuals) and
increased on a single day's exposure to 10°C and with duration of food deprivation. Use of torpor was highest during the day,
varied between individuals, and torpor bouts of greater than 24h duration were not noted. With food deprivation, individuals
at 25°C initially responded by reducing activity but remained euthermic while the same individuals at 10°C responded by increasing
their use of torpor during the light period; this difference in response probably reflects a difference in the relative energetic
benefits of torpor at different temperatures. 相似文献
2.
3.
4.
Age determination and age structure in the edible dormouse Glis glis based on incremental bone lines
1. Absolute age was estimated from incremental bone layers of the mandible in 109 edible dormice Glis glis collected between May and September 1997 in mixed beech and fir forests of central Slovenia. 2. Mandible cross-sections of juveniles obtained in September showed a great number of vascular canals and no resting lines. In the remaining animals (n = 81), the number of resting lines varied between one and seven, with two or three lines being the most common condition (62% of specimens). Among these adult animals, which hibernated at least once, females attained higher mean (3.3 years) and maximum age (7 years) than males (mean = 2.2, maximum = 6 years). 3. The frequency distribution of age classes suggested unequal reproductive success between years but there was no indication of any lack of litters in years of low mast production. 相似文献
5.
Modelling space use and dispersal of mammals in real landscapes: a tool for conservation 总被引:7,自引:0,他引:7
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. 相似文献
6.
Polyandry by wood mice in natural populations 总被引:1,自引:0,他引:1
The microhabitat used by the garden dormouse Eliomys quercinus during its nocturnal activity was examined. Twenty-three variables describing habitat structure were measured at 100 trapping points. Logistic regression models were utilized to select the variables that discriminate between used and avoided trapping points and, in a series of pairwise contrasts, between trap sites used by different sexes, age classes and animals in different reproductive periods. Used sites were characterized by a higher (>40%) rock cover, a thicker shrub layer and a younger understory with trees of smaller trunk diameter. These variables describe areas with rockfalls from the upper slope, where trees were younger and smaller, the canopy closure reduced and the shrub layer more developed than in other parts of the forest. Dense shrubby vegetation provided protection from aerial predators and, in conjunction with rocks and stones, might have made hunting by birds and mammals more difficult. Garden dormice may also have been attracted by rocky areas acting as a heat source during the night. The selection of rocky areas was more important in the first months of the active period, when animals emerged from hibernation and started the mating season. At the end of summer, the animals used areas richer in herbs, where insects and other food resources were probably more abundant. 相似文献
1