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During the period 1973–1976, eyes from 17 elks (Alces a. alces L) were examined, bilateral cataract being found in nine elks, and a cataract found in an additional elk, from which only one eye was submitted for examination. Macro-scopically, the lenses were more or less deformed and reduced in size, being milky white or brownish grey and shrunk, their surface uneven and granular. Microscopically, there was a marked fluid accumulation between the lens fibers and apparently also a swelling of the lens fibers. Proliferation and swelling of epithelial cells were observed as well. Etiological factors are discussed.  相似文献   

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Ketanserin, a peripheral serotonin (S2) receptor blocker, was evaluated as a therapy for stress induced hyperthermia in 18 wild, recently captured Rocky Mountain Elk (Cervus canadensis). The experiments were carried out in an outdoor experimental laboratory on two hot (>33°C) days separated by a week. Animals were randomly allocated to receive ketanserin (0.1 mg/kg, IV) or saline (4 ml, IV) following induction of hyperthermia via herding into distribution chutes and a squeeze cage during the first day. One week later, the experiments were repeated in the same fashion except that ketanserin and saline were not administered, and temperatures and heart and respiratory rates were not measured. Ketanserin produced dramatic decreases in temperature (43 ± 1 to 40 ± 0°C), and heart (110 ± 12 to 77 ± 5 beats/min) and respiratory rates (56 ± 7 to 26 ± 5 breaths/min), while saline resulted in no change in any of the measured variables. None of the elk died the first day; however, 1 week later, three elk died within 4 hours of completion of the experiment. All three animals had had temperatures of 45° C or above the previous week and had received ketanserin.  相似文献   

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Seven of 18 elk on a deer farm were found by the official Rose‐Bengal agglutination test (RBT) and tube agglutination test to be brucellosis reactors/suspects. Evaluation with the competitive ELISA (C‐ELISA) and the fluorescence polarization assay (FPA) tests revealed that six and five sera were positive respectively. The seven reactors/ suspects were slaughtered and their blood and tissues were collected. Brucella species could be isolated from three of the slaughtered animals, with nine isolates being obtained from the popliteal, supramammary and submandibular lymph nodes, vaginal discharge, mammary tissue and spleen. Brucella genus‐specific PCR based on 16S rRNA and AMOS‐PCR, which is specific for differential Brucella species, revealed that all nine isolates were Brucella abortus. These nine were further confirmed to be B. abortus biovar 1 by classical biotyping scheme assays. This is the first report of an outbreak of brucellosis in domestic elk in Korea. Our observations suggest that deer should be included in the routine Brucella surveillance programme for the effective control and prevention of brucellosis in Korea.  相似文献   

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Nutritional condition drives large herbivore population performance and is related to precipitation and forage quality in the arid Southwest. Because precipitation is difficult to measure at home-range scales, we tested whether satellite-derived vegetation indices of landscape greenness (i.e., indices of vegetation phenology or photosynthetic activity including normalized difference vegetation index [NDVI], soil-adjusted vegetation index [SAVI], and enhanced vegetation index [EVI]) were correlated to the condition of three species of large herbivores (elk, mule deer, pronghorn). We used canonical correlation analysis to relate seasonal landscape greenness with several measures of large herbivore condition. We also used linear mixed models to relate each measure of condition to seasonal landscape greenness separately for each herbivore population-year to see if any patterns were masked by multivariate analysis. Landscape greenness indices were only weakly related to condition of large herbivores, and the effect of landscape greenness on condition was always weaker than lactation status with the exception of pronghorn, an income breeder. Different indices also frequently gave highly variable and conflicting relationships between seasonal landscape greenness and condition of large herbivores. Overall, expected positive relationships between herbivore condition and landscape greenness indices were seen in only 8% of 2 988 possible outcomes. Because indices of landscape greenness are increasingly being used to relate wildlife population demographics to precipitation through a presumed effect on forage quality and resultant nutritional condition, we caution this use in arid environments unless a direct landscape greenness-forage quality or greenness-condition link is demonstrated.  相似文献   

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Incidents of human–wildlife conflict can solidify participant perspectives and expectations, and reveal underlying social and institutional dynamics. We describe and analyze two incidents of conflict between hunters and grizzly bears in 2011 and 2012. Both incidents were associated with the controversial elk hunt in Grand Teton National Park, Wyoming. We gathered quotes from opinion-editorials and interviews, categorized quotes according to type, and used cluster analysis to identify discourses and associated coalitions of participants. We examined how participants defined problems, used evidence, and advocated solutions in relation to these incidents. Participant discourses addressed technical and procedural issues of regional wildlife management that extended beyond these incidents, revealing divergent expectations about wildlife management on public lands. Existing decision-making processes dominated by government agencies do not appear to be addressing these expectations. We recommend an integrative, outside appraisal of regional elk management to address conflict and support ecologically sound decision-making that serves common interests.  相似文献   

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Concentrated herbivory by elk (Cervus elaphus) can degrade vegetative communities and alter ecosystem processes. Areas severely damaged by elk are commonly protected with woven wire fence, which can exclude other animals. Complete exclusion and prevention of large mammal herbivory might not always be necessary to restore vegetative communities. We designed and evaluated a simple fence that excluded elk, but maintained access for deer and other species. We enclosed a 1-ha stand of quaking aspen (Populus tremuloides Michaux) with our fence in an area with a high density of elk. We monitored effectiveness of the fence with trackplots, animal-activated cameras, and changes in aspen stem height and density. We documented only 1 elk within the exclosure in 2 years of monitoring. Mammals that used the exclosure included beaver (Castor canadensis), black bear (Ursus americanus), bobcat (Lynx rufus), coyote (Canis latrans), deer (Odocoileus spp.), mountain lion (Puma concolor), raccoon (Procyon lotor), red fox (Vulpes vulpes), and lagomorph (Leporidae). After 1 year of protection, mean aspen stem height increased 14.5 cm more inside the exclosure than outside, but stem density in the exclosure changed little compared to outside. Our fence design effectively excluded elk and has potential for protecting a variety of resources.  相似文献   

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麋鹿重组朊蛋白单克隆抗体的制备及初步鉴定   总被引:1,自引:0,他引:1  
为研制鹿慢性消耗性疾病(chronic wasting disease,CWD)单克隆抗体,本研究以原核表达后经纯化的麋鹿重组成熟朊蛋白(PrPc)为免疫原免疫PrPc基因敲除小鼠(PrPc-null mice)。两次加强免疫后,利用淋巴细胞杂交瘤技术,取脾细胞与SP2/0骨髓瘤细胞进行细胞融合,间接ELISA方法筛选阳性杂交瘤细胞,采用3次有限稀释法实现杂交瘤细胞的亚克隆,筛选出5株能稳定分泌针对麋鹿重组成熟朊蛋白特异性单克隆杭体(McAbs)的杂交瘤细胞株5A5、3B2、6D12、5E3、1F5,其腹水ELISA效价均达到1∶10000以上。经鉴定,5株单抗均为IgG抗体,5A5、6D12、5E3株为IgG1亚类,3B2、1F5株为IgG2a亚类。Western blotting鉴定结果表明,获得的McAbs均能特异性识别麋鹿重组成熟朊蛋白和健康麋鹿脑组织匀浆中的PrPc。本研究制备了CWD腹水McAbs,同时也为CWD的研究及其诊断方法的建立奠定了基础。  相似文献   

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半散放东北马鹿人工授精技术   总被引:1,自引:0,他引:1  
人工授精技术的关键是母鹿的发情鉴定。半散放母鹿的发情表现分为 3种类型 :隐性发情、表现发情和发情 ,表现类型不同 ,受孕率也不同。发情母鹿的受孕率为 95 0 0 % ;表现发情母鹿的受孕率为 71 43 % ,隐性发情母鹿的受孕率为 5 0 0 0 %。人工授精输精率为 85 5 8% ,受孕率为 78 65 %。同自然繁殖的母鹿相比 ,受孕率提高近 3 0 %。  相似文献   

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Lactation can have significant costs to individual and population-level productivity because of the high energetic demands it places on dams. Because the difference in condition between lactating and dry Rocky Mountain elk (Cervus elaphus nelsoni) cows tends to disappear as nutritional quality rises, the magnitude of that difference could be used to relate condition to habitat quality or the capability of habitats to support elk. We therefore compared nutritional condition of ≥ 2.5-yr-old lactating and dry cows from six free-ranging Rocky Mountain elk populations throughout the United States. Our goal was to quantify differential accrual of body fat (BF) reserves to determine whether the condition of dry and lactating cows could be used to define relevant management thresholds of habitat quality (i.e., relative carrying capacity) and consequently potential performance of elk populations. Levels of BF that lactating cows were able to accrue in autumn and the proportional difference in BF between dry and lactating cows in autumn were related (F1–2,10 ≥ 16.2, P < 0.001). Models indicated that elk experienced no negative effects of reproduction on condition when lactating cows were able to accrue ≥ 13.7% BF in autumn. When lactating cows are accruing ≤ 7.9% BF, elk are in a nutritionally stressed condition, which may be limiting population performance. Using the logistic model to predict relative proximity to ecological carrying capacity (ECC), our population-years ranged from 3–97% of ECC and proportion of the population lactating (an index of calf survival) was negatively related to proportion of ECC. Results indicate that the proportional difference in accrual of BF between lactating and dry cows can provide a sensitive index to where elk populations reside relative to the quality of their range.  相似文献   

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Global energy demand is predicted to increase dramatically, suggesting the need to understand the role of disturbance from energy development better and to develop more efficient conservation strategies for affected wildlife populations. We evaluated elk (Cervus elaphus) response to disturbance associated with natural gas development in summer and winter, including shifts in resource selection and concomitant distribution. We collected elk locations prior to (1992–1995) and during (2008–2010) coal bed natural gas (CBNG) development in the ∼ 498-km2 Fortification Creek Area (FCA) of northeastern Wyoming, USA, where approximately 700 CBNG wells and 542 km of collector, local, and resource roads were developed from 2000 through 2010. We developed resource selection functions for summer and winter using coordinate data from VHF-collared female elk prior to CBNG development and similar location data from GPS-collared female elk during CBNG development to assess spatial selection shifts. By pooling across all locations we created population level models for each time period (e.g., pre- and during development) and incorporated individual variation through bootstrapping standard errors for parameter estimates. Comparison of elk resource selection prior to and during natural gas development demonstrated behavioral and distributional shifts whereby during development, elk demonstrated a higher propensity to use distance and escape cover to minimize exposure to roads. Specifically, during-development elk selected areas with greater Rocky Mountain juniper (Juniperus scopulorum Sarg.) cover, increased terrain ruggedness, and farther from CBNG roads than prior to development. Elk distributional changes resulting from avoidance behavior led to a loss of high-use areas by 43.1% and 50.2% in summer and winter, respectively. We suggest reducing traffic, protecting woody escape cover, and maintaining refugia within the energy-development footprint to promote persistence of elk within energy fields.  相似文献   

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Use of mechanical thinning and prescribed fire to reduce fuels in dry forest ecosystems has become increasingly common in western North America. Nevertheless, few studies have quantified effects of fuels reduction treatments on wildlife. We evaluated effects of fuels reduction on quantity and quality of forage available to elk (Cervus elaphus) in northeastern Oregon. From 2001 to 2003, 26 stands of true fir (Abies spp.) and Douglas-fir (Pseudotsuga menziesii [Mirbel] Franco) were thinned and burned, whereas 27 similar stands were left untreated to serve as experimental controls. We estimated percentage of cover, percentage of in vitro dry-matter digestibility (digestibility), and percentage of nitrogen (%N) of 16 important forage species and genera in treatment and control stands during spring (May–June) and summer (July–August) of 2005 and 2006. Quantity and quality of forage were lower in summer than spring in both stand types. In contrast, total cover of forage was higher in treatment than in control stands during spring, whereas the opposite was true during summer. For graminoids, %N was higher in control than in treatment stands whereas digestibility did not differ between stand types. For forbs, neither index of forage quality differed between stand types. When treatment stands were separated by years since burning, %N and digestibility of forbs and %N of graminoids increased from 2 to 5 yr following treatment, and by the fifth year after burning had exceeded maximum values observed in control stands in both seasons. As a result of the interacting effects of fuels reduction and season on forage characteristics, treated stands provided better foraging opportunities for elk during spring, whereas control stands provided better foraging opportunities during summer. Consequently, maintaining a mosaic of burned and unburned (late successional) habitat may be of greater benefit to elk than burning a large proportion of a landscape.  相似文献   

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