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921.
Twelve collections of sagebrush, representing eight taxa at an unfenced plot near Price, Utah, were investigated to determine if the relative levels of eight major volatile compounds in the leaves influenced mule deer utilization of the various taxa during the winter. The compounds investigated were methacrolein, -pinene, camphene, β-pinene, arthole, 1,8-cineole, p-cymene, and camphor. Stepwise regression analysis indicated that one-fifth or less of the variability in utilization could be attributed to the relative percentages of the volatile constituents in the leaves. Oxygenated compounds (especially methacrolein and arthole) seemed to be more highly correlated with sagebrush utilization than hydrocarbons, and this correlation appeared to be inverse.  相似文献   
922.
Abstract: Conducting surveys from blinds when supplemental feed (bait) has been provided has not been evaluated for estimating parameters of ungulate populations. We conducted blind count surveys of white-tailed deer (Odocoileus virginianus) in a 214-ha enclosure in central Texas, USA, in 2007 and 2008 to address 2 main objectives: 1) to evaluate a blind count survey protocol developed for use on small parcels of land, and 2) to use data collected from blind count surveys to conduct simulations to evaluate the reliability of abundance and sex ratio estimates obtained from Bowden's estimator. In each year population abundance (2007: 60; 2008: 48) and sex ratio (M:F, 2007: 0.58; 2008: 0.71) were known as were sighting frequencies of every animal. The enclosure had 5 blinds and we baited each blind with corn. We encountered many deer during surveys because there were only 2 deer in 2007 and 1 deer in 2008 that we did not view from blinds ≥1 time. To evaluate bias and precision of abundance and sex ratio estimates we conducted 10,000 bootstrap simulations. We evaluated both parameters in relation to the percentage of each population marked, number of surveys conducted from blinds, and whether surveys were conducted in the morning, evening, or both morning and evening. Also, we evaluated abundance in relation to whether we identified animals with unique marks to individual, and we evaluated sex ratio in relation to intersexual distribution of marks. Abundance estimates were less biased and more precise when we uniquely identified all marked animals and 40–70% of the population was marked. Sex ratio estimates were less biased when 40–70% of the population was marked and surveys were conducted in the morning and evening. Sex ratio estimates, however, were less precise than abundance estimates. Unbiased estimates of white-tailed deer population parameters can be obtained from blind count surveys conducted on small parcels of enclosed land and when animals are baited.  相似文献   
923.
The effects of routine sperm work are often overlooked. We assessed the effect of washing cryopreserved epididymal spermatozoa from red deer (Cervus elaphus hispanicus, Helzheimer 1909). After thawing, epididymal samples (four stags) were diluted in TALP-HEPES. A split was left untouched, another was centrifuged (300 × g, 5 min) and resuspended, and a third was centrifuged and the supernatant substituted by fresh TALP-HEPES (washing). Each split was supplemented either with nothing, 1 mM of the antioxidant Trolox, 100 μM of the oxidant Fe (with ascorbate), or both. The 3 × 4 treatments were incubated at 37°C and assessed each hour up to 3 h for motility (computer-aided sperm assessment) and viability/apoptosis plus mitochondrial status (YO-PRO-1, propidium iodide, Mitotracker Deep Red; flow cytometry). DNA damage at 4 h was assessed using the terminal deoxynucleotidyl transferase–mediated dUTP nick end-labeling assay. Centrifugation alone affected neither sperm quality nor DNA, and the oxidant had no effect in control or centrifuged samples. Washed samples were not different than control, but oxidant decreased motility, mitochondrial status and viability, and altered the motility subpopulation pattern, being partially suppressed by Trolox. Spermatozoa with damaged DNA dramatically increased in the washed-oxidized sample (from 22.30 ± 3.52% to 67.94 ± 5.07%), but not when antioxidant was present. Although samples from different males behaved similarly, male-to-male variability was detected regarding susceptibility to oxidative damage after washing. We concluded that, although red deer thawed spermatozoa seemed resilient to centrifugation, the vulnerability to oxidative stress after washing makes it advisable to supplement manipulation media with antioxidants, especially taking into account male-to-male variability.  相似文献   
924.
In all areas where they have been studied, male roe deer are believed to have a territorial mating system, although few quantitative studies have been conducted and there remains considerable debate about the function of male roe deer territories. We observed 139 aggressive interactions between male roe deer in Storfosna Island (Norway) during one territorial season (March–August). We recognised seven rank levels of escalation according to the potential danger of the behaviour. On the basis of the number of escalation levels included in the interactions, the complexity of the fights was also scored. We recorded the presence of other individuals during the interaction, the age, the antler size, the territorial status and the residency status of the two contestants and tested how these variables affected escalation, complexity and outcome of the fights. Most of the interactions ended with low levels of escalation, and physical contact occurred only in fights between two territorial bucks. The escalation was also affected by the difference in antler size index (the bucks escalated more when the difference in antler size was smaller) and increased with an increasing number of female deer present during the interaction. The resident buck won in 81% of the fights. When it drew or lost, it was generally both inferior in age and antler size, and the duration and escalation of the interactions were higher. However, even when a fight was lost, no territory loss occurred. These results are consistent with the evolutionary game theory and the proposed low risk–low gain strategy of roe deer bucks.  相似文献   
925.
Access to lands for hunting is widely recognized as critical to sustaining and developing participation in hunting. Deer hunters comprise a substantial portion of recreational hunters in the United States, and numerous stakeholders benefit from the deer management services provided by hunters on public lands. We estimated the economic value of publicly accessible deer hunting land in Michigan using economic models of hunting destinations for hunters in the archery season and for hunters in the firearm season. We found that the amounts of state-owned hunting land, federally owned hunting land, and publicly accessible, privately owned Commercial Forest Act land are significant (P < 0.001) and positive determinants of hunting destinations. The annual economic value of Michigan's publicly accessible hunting land to archery and firearm deer hunters, beyond hunter expenditures, was estimated to be over $80 million. Access to state-owned land accounted for approximately $50 million in annual economic value to Michigan deer hunters. The average per-acre value of publicly accessible hunting land is greatest in the Southern Lower Peninsula of Michigan, where public access is scarce and the majority of hunters reside. Understanding the economic values hunters derive from publicly accessible hunting lands will enable managers and policy makers to make better decisions when considering policy options that involve reducing or increasing public access. © 2011 The Wildlife Society.  相似文献   
926.
Abstract: Acom production by oaks (Quercus spp.) is an important food resource for wildlife in many deciduous forests. Its role as a hard mast crop that can be either stored or used to build fat reserves for winter survival cannot be replaced by most other potential foods. Changes in forest management, introduced pests and pathogens, and increased deer populations have resulted in significant changes in the demography of oaks in eastern North America, as evident in Forest Inventory and Analysis data. Specifically, maples (Acer spp.) are replacing oaks in many forests through dominance of the younger age classes. These changes are not yet obvious in mast production but will take decades to reverse. Effective forest management for mast production is arguably one of the more important tasks facing wildlife professionals, yet receives scant attention by both public and private land managers. Public forests need to explicitly include mast production in their forest planning and reduce adversarial relationships over forest management. Market forces are driving commercial forests toward forest certification. Private forests compose 80% of our oak forests and are the hardest group to influence. States have not been able to effectively market forest plans and we recommend joining with advocacy groups more adept at motivating the public. Increased communication between wildlife and forestry professionals is needed through agency restructuring and joint meetings of professional agencies at the state level. Professional wildlife and forest managers are encouraged to make increased use of monitoring data and form a multiagency cooperative using a joint venture model, which has been successful for other organizations.  相似文献   
927.
The small red brocket deer Mazama bororo is one of the most endangered deer in the Neotropics. The great morphological similarities with three other sympatric brocket deer species, coupled with the fact that they inhabit densely forested habitats complicate detection and prevent the use of traditional methodologies for accurate identification of species. The ability to determine the presence of this endangered species in an area is crucial for estimating its distribution range, and is critical for establishing conservation management strategies. Here we describe a fast and reliable noninvasive genetic method for species identification of Mazama species from faeces. We designed a primer set that amplifies a short 224-bp fragment of the cytochrome b and demonstrate its effectiveness in successful amplification of DNA isolated from both tissue and faecal samples. This fragment contains a BSTNI/ECORII digestion site that is unique to the endangered M. bororo. The digested polymerase chain reaction products yielded a 160-bp fragment that is clearly visible in a 2% agarose gel. Two other diagnostic sites were identified to differentiate the other three sympatric species, SspI (M. gouazoubira) and AflIII (M. americana, and M. nana).  相似文献   
928.
Aim  Landscape structure influences the distribution of animals, altering their movements and their ability to reach habitat patches. We analysed the spatial patterns of dung beetle species diversity in three differently structured natural landscapes in a Mediterranean protected area in the centre of the Iberian Peninsula.
Location  Cabañeros National Park, Central Spain.
Methods  Diversity components within (α) and among (β) the three main vegetation types in the reserve were compared by using a hierarchical nested design. These were forests, scrublands and grasslands embedded in three different landscapes, where each was the most dominant and structurally connected habitat.
Results  Species richness of grassland habitat did not vary across landscapes, but forest habitat showed lower species richness in the grassland-dominated landscape. Scrubland was the least species-rich habitat, but here again there was no significant variation across landscapes. However, in all cases, there was a significant influence of habitat context (configuration of habitat patches within landscape matrix) on similarity of species composition. These tended to be more similar to the dominant landscape matrix where they were embedded, rather than to the same habitat type in other landscapes. Additive partitioning of diversity showed higher than expected values of β in all landscapes, which indicated a structured response. Highest values of β in the grassland-dominated landscape suggest that this was the least connected landscape for dung beetles.
Main conclusions  Our results suggest that in homogeneous conditions of climate and trophic resources, landscape structure may well be more important than habitat type as a determinant of dung beetle distribution in the Mediterranean.  相似文献   
929.
ABSTRACT White-tailed deer (Odocoileus virginianus) browsing in forest regeneration sites can affect current and future stand structure and species composition. Removal of deer social units (localized management) has been proposed as a strategy to alleviate deer overbrowsing in forest systems. We conducted an experimental localized removal in a high-density deer population in the central Appalachians of West Virginia, USA, during winter 2002. We removed 51 deer within a 1.1-km2 area that encompassed 2 forest regeneration sites (14 ha). During the summer following removal, we detected decreases in distance from the removal area in 8 of 30 (26.7%) adult females having pretreatment mean telemetry locations <2.5 km from the center of the removal area. We measured browsing rates during the summers of 2001–2004 from forest regeneration sites to examine efficacy of localized management. Browsing rates declined annually in both removal and control areas, due in part to increased timber harvesting on the larger study site, suggesting that increasing forage availability may be more effective at reducing impacts on forest regeneration than localized reductions in deer populations. Three years after the initial removal, we removed an additional 31 deer from the original 1.1-km2 removal area. Home range shifts of adjacent deer coupled with the large number of animals collected in the second removal suggests that localized management only produces temporary voids within high-density deer herds. Localized management may not effectively reduce negative impacts of deer in areas of high deer density.  相似文献   
930.
Leishmaniasis is a complex human disease caused by intracellular parasites of the genus Leishmania, predominantly transmitted by the bite of sand flies. In Italy, leishmaniasis is caused exclusively by Leishmania infantum, responsible for the human and canine visceral leishmaniases (HVL and CVL, respectively). Within the Emilia-Romagna region, two different foci are active in the municipalities of Pianoro and Valsamoggia (both in the province of Bologna). Recent molecular studies indicated that L. infantum strains circulating in dogs and humans are different, suggesting that there is an animal reservoir other than dogs for human visceral leishmaniasis in the Emilia-Romagna region. In this work, we analyzed specimens from wild animals collected during hunts or surveillance of regional parks near active foci of human visceral leishmaniasis for L. infantum infection in the province of Bologna. Out of 70 individuals analyzed, 17 (24%) were positive for L. infantum. The infection prevalence in hedgehogs (Erinaceus europaeus), roe deer (Capreolus capreolus), badgers (Meles meles), and bank voles (Myodes glareolus) was 80, 33, 25, and 11%, respectively. To distinguish the two strains of L. infantum we have developed a nested PCR protocol optimized for animal tissues. Our results demonstrated that most (over 90%) of L. infantum infections in roe deer were due to the strain circulating in humans in the Emilia-Romagna region.  相似文献   
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