首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
The size and structure of the chamois (Rupicapra rupicapra caucasica) population as well as the influence of anthropogenic factors on it were studied on the Caucasian Reserve (Western Caucasus). The negative effect of the snow cover, the thickness of which differed from the usual level, is shown. The effect of winters with thick snow cover is confirmed by the relation between these factors and the proportion of yearlings in the population one year after the winter. An increased death rate of animals in winters with a deep snow cover is observed in the case when their density exceeds the optimal one. Wolf predation does not affect the chamois population on the reserve. The number of wolves increases with an increase in the chamois population density to 15–20 ind./1000 ha. The adverse impact of humans on the chamois population is manifested in the regions with motor roads. The chamois, as compared to the deer, suffers from poachers to a lesser degree because it inhabits inaccessible areas and its trophy value is low.  相似文献   

2.
Global climate change can affect animal ecology in numerous ways, but researchers usually emphasize undesirable consequences. Temperature increases, for instance, can induce direct physiological costs and indirect effects via mismatches in resource needs and availability. Species living in mountainous regions, however, could experience beneficial effects because winters might become less severe. We examined the potentially opposing effects of climate change during spring, summer, and winter on recruitment in Alpine chamois (Rupicapra rupicapra). We examined initial recruitment (i.e., the ratio of kids to adult females) and net recruitment (i.e., the ratio of yearlings to adult females) of Alpine chamois through the use of linear mixed effects models and data from block count censuses performed across a 1,500-km2 study area in the Italian Alps during summer from 2001 to 2015. Initial recruitment was relatively resistant to the effects of climate change, declining slightly over the study period. We suggest that the effects of increased forage availability and lower snow cover in winter may benefit the reproductive output of adult females, compensating for any negative effects of trophic mismatch and higher temperatures during summer. By contrast, net recruitment strongly declined throughout the study period, consistent with the slight decline of initial recruitment and the negative effects of increasing summer temperatures on the survival of kids during their first winter. These negative effects seemed to outweigh positive effects of climate change, even in a species strongly challenged by winter conditions. These findings provide important information for hunted populations; setting more appropriate hunting bags for yearling chamois should be considered. The ecological plasticity of the chamois, which also inhabits low altitudes, may allow a possible evolutionary escape for the species. © 2020 The Wildlife Society.  相似文献   

3.
Monitoring nutritional status of wildlife is key to understanding the population response to changes in food availability. Several direct and indirect methods have been proposed for such purposes, but faecal nitrogen (FN) is by far the most commonly used indirect non-invasive indicator of free-ranging ruminant diet quality. In this work, two methods were used to estimate the FN content in 291 pellet samples of Pyrenean chamois (Rupicapra pyrenaica pyrenaica) collected during a 2-year period (May 2009 to May 2011) in two chamois populations from the Catalan Pyrenees, Spain: the Dumas LECO analyzer and near-infrared reflectance spectroscopy (NIRS). In order to optimize further FN estimations we performed three different NIRS calibrations: (1) general, across year, season and populations; (2) population-specific; and (3) season-specific, i.e., different periods of vegetation growth. FN ranged from 1.66 % to 2.85 % (dry matter basis) and was higher in the main vegetation growing season than in winter. Concerning NIRS calibration, our study confirmed that FN of Pyrenean chamois can be accurately determined by NIRS, since the general calibration was accurate enough to predict FN. It is concluded that NIRS represents a non-destructive, emission-free and low-cost analytical technique which may reduce the use of conventional laborious methods for estimating FN in long-term wildlife monitoring.  相似文献   

4.
Seasonality deeply affects the physiology and behavior of many species, and must be taken into account when biological resource banks (BRBs) are established. We have studied the effect of seasonality on many reproductive parameters of free-ranging Iberian red deer, roe deer and Cantabrian chamois, living in Spain. Testicles from hunted animals were collected and sent to our laboratory at different times during the year. We recorded the weight and volume of testis, the weight of the epididymis and its separate parts (caput, corpus, and cauda), the weight of the sperm sample collected from the cauda epididymis, and several sperm parameters (sperm concentration, spermatozoa recovered, motility, HOS test reactivity, acrosomal status, and viability). We studied the data according to several periods, defined accordingly to each species. For red deer, we defined rut (mid-September to mid-October), post-rut (mid-October to mid-December), and non-breeding season (February). For roe deer, they were pre-rut (June), rut (July), post-rut (first fortnight of August), and non-breeding season (September). For chamois: non-breeding season (June to mid-September) and breeding season (October-November). The rut/breeding season yielded significantly higher numbers for almost all parameters. However, in the case of red deer, sperm quality was higher in the post-rut. For roe deer, testicular weight was similar in the pre-rut and in the rut, and sperm quality did not differ significantly between these two periods, although we noticed higher values in the rut. In the case of chamois, sperm quality did not differ significantly from the breeding season, but data distribution suggested that in the non-breeding season there are less males with sperm of good quality. On the whole, we find these results of interest for BRB planning. The best season to collect sperm in this species would be the breeding season. However, post-rut in red deer, pre-rut in roe deer, and non-breeding season in chamois could be used too, because of the acceptable sperm quality, despite the lower quantity salvaged. More in-depth research needs to be carried out on the quality of sperm salvaged at different times of the year in order to confirm these findings.  相似文献   

5.
We used an enclosure trap with a lifting net to capture Alpine chamois (Rupicapra rupicapra). The trap was activated by remote radio-controlled electromagnets powered by photovoltaic modules. The up-net trap had considerable advantages over mechanical methods described in the literature for the capture of chamois. During 36 capture sessions, we captured 50 chamois, or 1.39 animals per session. Capture success was 96.2% of the average of 1.4 animals that entered the trap during a capture session. Mortality was 2%, and another 2% of the captured chamois was injured. There were no known postrelease capture-induced pathologies, and the capture effort was 1.7 man-days per chamois. The trap allowed to select specific target animals and to capture sex–age classes (particularly kids and their mothers) that are normally difficult or impossible to capture. It could be set off from a distance; it only required about 4 h to assemble and could be operated by as few as two people.  相似文献   

6.
In recent years, the use of satellite-derived vegetation indices has become a powerful tool to collect information on vegetation dynamics in a broad range of ecosystems worldwide. However, the utility of these indices as indicators of the diet composition and quality of herbivore mammals has not yet been established. This work focuses on exploring such relationships analysing four years of records of monthly Enhanced Vegetation Index (EVI, a MOD13 satellite-derived index) and diet composition and quality of two populations of chamois (Rupicapra pyrenaica pyrenaica) in the Eastern Pyrenees (Spain). Our results revealed that 68.4% and 53.3% of diet composition and quality of chamois can be explained by EVI values in the green-up season (spring) and green senescence (winter season), respectively. In both periods, EVI was related mainly to diets low in fibre (cellulose, hemicellulose and lignin) and heather (Calluna vulgaris) and high in nitrogen due to the consumption of Festuca, Forbs and Trifolium. During the summer season however, the EVI was not significantly related to diet components of chamois. A significant inter-year variability in the diets of the chamois was also observed. To conclude, remote sensing is appropriate to assess temporal variations in dietary components of mountain ungulates, and could be used as a component of monitoring large herbivore populations in management programmes.  相似文献   

7.
The chamois of Abruzzi (Rupicapra pyrenaica ornata) has been classified as endangered by the World Union for Conservation. The objective of this study was to analyze seasonal differences in the characteristics of various male reproductive organs and in semen quality. The study was conduced during 2004 in the reserve of Lama dei Peligni (Italy) on three chamois males aged between 2 and 5 years. Males were captured during March-May months and October-December months. Various testicular and scrotal measurements were taken and semen was collected using an electroejaculator. Sperm motility pattern was evaluated using computer assisted sperm analyzer, membrane integrity using differential staining and morphology with phase contrast microscopy. Testicular size, sperm motility membrane integrity and the percent of morphological normal spermatozoa were greater during October-December. The authors concluded that sperm characteristics are strongly influenced by season and that semen collected in this period (breeding season) has suitable quality for manipulation and long-term preservation.  相似文献   

8.
Abstract

The physical and demographic characteristics of chamois in the Avoca region are evaluated from 306 animals shot and autopsied between 1975 and 1978. These data are compared with published and unpublished information for chamois populations in Westland and Canterbury. Avoca chamois were large-framed, but weighed less than Westland chamois. The weight difference suggests better habitat condition and food resources for Westland animals, but the large skeletal size of Avoca chamois is unexplained.

High rates of juvenile mortality were caused by acute bacterial-pneumonia infections (Pasteurella). These deaths and other losses by natural causes were offset by the good breeding success of adult females so that stable population numbers were maintained.  相似文献   

9.
We demonstrated that the level of phospholipids in the liver mitochondrial fraction is increased by 60% during the winter hibernation season in the Yakut ground squirrel S. undulatus; the phospholipid composition in sleeping animals is characterized by an increase in phosphatidylethanolamine compared with summer animals. A sharp increase in the level of cholesterol, as well as fatty acid, monoglycerides, and diglycerides was found in the mitochondrial fraction of hibernating ground squirrels in relation to summer ground squirrels. Functional changes during hibernation concern the level of phosphatidylserine (the growth in sleeping animals compared with active animals). Seasonal modification of the lipid composition of the liver mitochondria (particularly, an increase in the level of cholesterol) can play a role in the resistance of mitochondria to the seasonal increase in the level of fatty acids in the liver. Lipids of the liver mitochondrial fraction are involved in the ground squirrel adaptation to the hibernation season.  相似文献   

10.
Ecological factors such as environmental and climatic conditions affect the growth of ornaments in ungulates. Studies about their influence can reveal key information on individual life histories and detect the events that can have important evolutionary consequences. Among the ecological factors commonly thought to play a role in such ecological processes, researches have so far neglected the possible influence of the geological feature which may either promote or restrain the early investment in horn growth. This study takes into consideration a broad range of ecological factors that are expected to affect horn growth and analyses how the substrate (calcareous versus siliceous) could modify the horn size in 1,685 yearling Alpine chamois (Rupicapra rupicapra) which were legally shot during 5 consecutive years in Central-Eastern Italian Alps. Interestingly, we found shorter horns in chamois shot on siliceous than on calcareous substrate, irrespective of the sex, showing how the substrate (and related ecological conditions) may affect horn growth. The substrate interacted with two ecological factors in shaping the horn size, i.e. aspect and snow cover. Differences between horn lengths recorded for chamois shot on these two substrates were less pronounced where South-facing slopes prevailed. During an average winter (about 100 days with more than 10 cm of snow on the ground) chamois horns were longer in individuals using calcareous areas, although the increase of number of days with more than 10 cm of snow on the ground had a stronger impact in reducing horn length in calcareous environment. We demonstrated that substrate, and related ecological conditions, influence horn growth. In ungulate species where ornament size is related to reproductive success, environmental factors, such as geological feature, can thus cause evolutionary consequences in the expression of ornaments and individual fitness.  相似文献   

11.
Abstract: We studied seasonal changes in fecal Cortisol metabolites (FCM), which have been widely used as indicators of stress, in a population of Pyrenean chamois (Rupicapra pyrenaica pyrenaica) in the Cadí Range of northeastern Spain. We collected fecal samples from 2001 to 2003 in 3 particular locations with different altitudes and male or female presence, and we analyzed them for FCM and fecal nitrogen as an indicator of diet quality. We observed a clear seasonal pattern, with the highest FCM in winter, and we obtained correlations between FCM and monthly mean minimum temperatures and fecal nitrogen. We observed no effects of tourism presence, trophy hunting, or rut season on FCM. Analysis of cortisol metabolites in feces can be a good measure of winter stress in Pyrenean chamois.  相似文献   

12.
Mycoplasma conjunctivae, the causative agent of infectious keratoconjunctivitis (IKC), was recently detected in asymptomatic Alpine ibex (Capra ibex ibex). This suggested that an external source of infection may not be required for an IKC outbreak in wildlife but might be initiated by healthy carriers, which contradicted previous serologic investigations in chamois. Our aims were to 1) assess the prevalence of M. conjunctivae among asymptomatic ibex and Alpine chamois (Rupicapra rupicapra rupicapra) and its frequency in IKC-affected animals, 2) determine mycoplasma loads in different disease stages, and 3) characterize the M. conjunctivae strains involved. Eye swabs from 654 asymptomatic and 204 symptomatic animals were collected in diverse Swiss regions between 2008 and 2010, and tested by TaqMan real-time PCR. Data analysis was performed considering various patterns of IKC occurrence in the respective sampling regions. Strains from 24 animals were compared by cluster analysis. Prevalence of M. conjunctivae was 5.6% (95% confidence interval [CI]: 3.7-8.1%) in asymptomatic ibex and 5.8% (CI: 3.0-9.9%) in asymptomatic chamois, with significant differences between years and regions in both species. Detection frequency in symptomatic animals was significantly higher during IKC outbreaks than in nonepidemic situations (i.e., regular but low incidence or sporadic occurrence). Mycoplasma load was significantly lower in eyes from healthy carriers and animals with mild signs than from animals with moderate and severe signs. Although some strains were found in both asymptomatic and diseased animals of the same species, others apparently differed in their pathogenic potential depending on the infected species. Overall, we found a widespread occurrence of M. conjunctivae in wild Caprinae with and without IKC signs. Our results confirm the central role of M. conjunctivae in outbreaks but suggest that other infectious agents may be involved in IKC cases in nonepidemic situations. Additionally, presence and severity of signs are related to the quantity of M. conjunctivae in the eyes rather than to the strain. We propose that individual or environmental factors influence the clinical expression of the disease and that persistence of M. conjunctivae in populations of wild Caprinae cannot be excluded.  相似文献   

13.
The occurrence of infectious keratoconjunctivitis (IKC) was assessed in alpine chamois (Rupicapra rupicapra rupicapra) in Grisons (Switzerland) from 1950 to 1999. The first IKC outbreaks were reported in the 1950's. Since then, the number of affected subpopulations constantly increased and, by 1999, IKC outbreaks were reported in 39 of 51 (77%) chamois sub-populations. From 1992-99, a total of 243 chamois which died of the consequences of IKC were recorded. The number of cases differed between years, and a distinct seasonal trend was observed. Infectious keratoconjunctivitis was more common during summer and autumn, with 48% of the cases recorded in August-October. Juveniles (< 4 yr of age) were mostly represented. To verify the presence of Mycoplasma conjunctivae in chamois we analyzed conjunctival swabs taken from animals affected with IKC. Among a sample of 28 affected chamois, M. conjunctivae was identified 14 times (50%). An indirect enzyme-linked immunosorbent assay (ELISA) was developed to detect specific M. conjunctivae antibodies in sera of alpine chamois with IKC. We performed a serologic investigation to assess whether M. conjunctivae infection is self-maintained in the chamois population in Grisons. In subpopulations with IKC oubreaks, seroprevalence was low (8%). Seroprevalence was even lower in subpopulations with recent IKC outbreaks (3%). We concluded that the M. conjunctivae infection is not self-maintained in alpine chamois in Grisons. The agent may originate in domestic sheep living in proximity to chamois during summer. Control of IKC in chamois should consider immunoprophylaxis in sheep or limiting interspecific transmission of M. conjunctivae.  相似文献   

14.
Responses of animals to environmental changes and their interactions with other species play an important role in conservation. Sharing a common habitat may lead to interspecific competition for resources, but field assessment of these biological events is not always easily accomplished. By using a non-invasive method, we evaluated the physiological stress responses of Apennine chamois (Rupicapra pyrenaica ornata) to the presence of cattle, sheep and goat, red deer (Cervus elaphus), people (hikers), and predators to identify which factors may affect this endangered species. During September 2012, November 2012, and July 2013, a total of 318 faecal samples were collected in representative sites and analysed for faecal cortisol metabolites (FCM). FCM concentration was analysed through linear mixed-effect models. A significant increase in FCM values in Apennine chamois sharing their habitat with domestic animals was recorded during all study periods. On the contrary, stress responses to red deer and people were limited in time and emerged only during summer months, when hikers are more frequent and red deer extend their altitudinal range reaching chamois’ habitat. The observed effects of domestic animals, red deer, and hikers should be considered in future Apennine chamois management plans, which should include the regulation of pastured domestic livestock, anthropogenic disturbances, and possible interferences with other wild species within parks.  相似文献   

15.
《Acta Oecologica》2003,24(4):187-193
In food-limited populations, the presence of extra food resources can influence the way individuals allocate energy to growth and reproduction. We experimentally increased food available to cotton rats (Sigmodon hispidus) near the northern limit of their range over a 2-year period and tested the hypothesis that seasonal growth rates would be enhanced by supplemental food during winter and spring when natural food levels are low. We also examined whether additional food resources were allocated to somatic growth or reproductive effort by pregnant and lactating females. The effect of supplemental food on growth varied with mass and season, but did not influence the growth rates of most cotton rats during spring and winter. In winter, small animals on supplemented grids had higher growth rates than small animals on control grids, but females in spring had lower growth rates under supplemented conditions. Growth rates of supplemented cotton rats were enhanced in summer. Northern cotton rat populations may use season-specific foraging strategies, maximizing energy intake during the reproductive season and minimizing time spent foraging in winter. Adult females invest extra resources in reproduction rather than in somatic growth. Pregnant females receiving supplemental food had higher growth rates than control females, and dependent pups (≤ 1 month of age) born to supplemented mothers had higher growth rates than those born to control mothers. Increased body size seems to confer an advantage during the reproductive season, but has no concomitant advantage to overwinter survival.  相似文献   

16.
Estimating animal abundances in small areas is a difficult task and because a limited number of observations often results in low-precision estimates whose inaccuracies may even be exacerbated if surveys are focussed on clustered populations and/or are only carried out once a year. In an attempt to overcome this problem, we used point transects to monthly survey two small areas of a game reserve to assess the density of Pyrenean chamois (Rupicapra p. pyrenaica). The coefficient of variation associated with the density estimates after pooling observations by season was still high but decreased to reasonable values (<20%) when observations were over 29 chamois groups (clusters). Our results suggest that Distance Sampling may be a useful way of estimating the population density of mountain ungulates such as Pyrenean chamois in small rugged areas where only a small or moderate number of observations are to be expected.  相似文献   

17.
Depending on the habitats they live in, temperate ungulates have adapted to different degrees to seasonally changing forage and weather conditions, and to specific escape strategies from predators. Alpine chamois, a mountain ungulate, and red deer, originally adapted to open plains, would therefore be expected to differ in their physiological responses to potential stressors. Based on 742 chamois and 1557 red deer fecal samples collected year‐round every 2 weeks for 4 years at the same locations within a strictly protected area in the Swiss Alps, we analyzed glucocorticoid metabolite (FGM) concentrations for both species. Results from linear mixed effects models revealed no physiological stress response to changing visitor numbers, but instead to drought conditions for both species during summer. In winter, FGM concentrations increased with increasing snow height in both species, but this response was modulated by temperature in red deer. Chamois showed a stronger stress response to increasing snow height during November and December than between January and March, while FGM concentrations increased with decreasing temperature throughout winter. An increase in FGM concentrations with decreasing forage digestibility during winter was found only for red deer. The results are thus partly in contradiction to expectations based on feeding type and adaptations to different habitats between the two species. The lack of a response to forage digestibility in chamois may reflect either better adaptation to difficult feeding conditions in subalpine forests, or, by contrast, strong constraints imposed by forage quality. The similar responses of both species to weather conditions in winter suggest that climatic factors at the elevations examined here are sufficiently harsh to be limiting to temperate ungulates regardless of their specific adaptations to this environment.  相似文献   

18.
In a multi‐prey system, predators kill different kinds of prey according to their availability, where “availability” is a function of prey abundance and vulnerability (e.g. anti‐predator behavior). We hypothesized that prey availability changes seasonally, for instance because reproduction leads to a higher abundance of young in spring and summer or because changes in behavior such as during the mating season makes the prey periodically more vulnerable. We tested this hypothesis in a simple predator‐prey system in the Jura Mountains of Switzerland and France, where a single large mammalian predator, the Eurasian lynx, preys upon two ungulate species, the roe deer and the chamois. In 1996 and 1997 we were able to assign a total of 190 roe deer and 54 chamois killed by lynx to a specific age and sex class (males, females or juveniles). As expected, the proportion of juveniles killed varied considerably among periods, being at the highest from 1st of June to 15th of August. No significant seasonal differences were detected regarding the frequency of predation on males versus females. In particular, the interaction between species and period, expected because of different timing of the rutting period between roe deer and chamois, was not significant. Females were killed only slightly more often during gestation. The relationship between prey abundance and vulnerability is highly complex, as the lynx’ prey selection needs to be analyzed not only horizontally (changes of a specific prey category with season) but also vertically (an increase in the vulnerability of one category releases predation pressure on others). Second, we predicted that certain activities, such as feeding, expose prey to predation more than others. We found more chamois predated when feeding, whereas roe deer were predated mainly when ruminating. This interspecific discrepancy reflects differences either in the anti‐predator behavior of roe deer and chamois or in the relative time allocation to feeding and ruminating between the two species.  相似文献   

19.
In golden hamster adapted to intermittent starvation (with access to food for 3 days a week only), the glycogen and lipid content of the liver, total body fat and RQ values measured in vivo were investigated. These parameters were studied in dependence on the duration of the adaptation period (6 weeks versus 20 weeks), season of the year (winter versus summer) and sex. The liver glycogen content in intermittently starved males and females increases after 6 weeks of adaptation during winter. In summer an increase was found after long-term adaptation, but only in males. Male hamsters also exhibited a higher ability to accumulate liver lipids during both seasons. In spite of their lower weight intermittently starving males have a higher percentage of body fat in comparison with females, a stimulating effect being observed in winter. Increased lipogenesis in golden hamsters adapted to intermittent starvation may be concluded from the increased RQ values when compared with relative data gained in controls fed daily ad libitum. Significant differences between RQ measurements according to season and sex were not found.  相似文献   

20.
Alpine species are often exposed to intense levels of human recreational activities. Exactly how human disturbances influence the behaviour of these species is still open to much debate. For example, little is known regarding how the colourful clothing often worn by tourists influences the behaviour of animals. Tourists wearing colourful clothing may be more conspicuous to local wildlife and thus cause more disturbances. We therefore investigated this question in female chamois (Rupicapra rupicapra) in the Swiss Alps. We firstly investigated, via a morphological and an immunohistochemical approach, whether chamois are likely to have colour vision and would therefore be more likely to respond to different coloured clothing. We detected evidence of two cone types—short-wavelength-sensitive cones (S-cones, JH 455) and middle-wavelength-sensitive cones (M-cones, JH492) in the chamois retina—suggesting that chamois have dichromatic vision, similar to other ungulates. Secondly, via behavioural assays where a person wearing one of three coloured coats commonly worn by tourists (red, yellow and blue) approached a female chamois, we show that neither the alert and flight initiation distance nor the site of refuge were influenced by the raincoat colour. In addition, behavioural responses of the chamois were neither influenced by animal group size nor the presence of kids nor the time of the experiment. The results suggest that, although chamois possess colour vision, they do not react more strongly towards conspicuous colours worn by hikers. We discuss our results in light of what is already known about chamois biology and suggest implications for future studies.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号