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51.
CHADWICK D. RITTENHOUSE JOSHUA J. MILLSPAUGH MICHAEL W. HUBBARD STEVEN L. SHERIFF WILLIAM D. DIJAK 《The Journal of wildlife management》2008,72(1):268-275
Abstract Resource selection is a multi-staged process of behavioral responses to various resource cues or stimuli. Previous research suggests some aspects of resource selection may be inherent (i.e., genetic predisposition) or based on early experience and that individuals respond to certain resource cues but not to others. In other words, resource selection may be based on a template that specifies which cues to use in the resource-selection process and the appropriate response to those cues. We used resource utilization functions (RUFs) to examine the resource-selection template of translocated three-toed box turtles (Terrapene carolina triunguis; hereafter turtles) and made comparisons to resident turtles. Translocated turtles, previously residents of a predominantly forested landscape with low edge-density, used forest openings, forest edges, and southwest-facing slopes before and after translocation to a fragmented site containing resident turtles. In contrast, resident turtles used forested areas and northeast-facing slopes within a predominantly open landscape with high edge-density. Our comparison of resource selection by translocated and resident turtles revealed population-specific resource selection and consistency in selection following translocation, which reinforces the idea of a resource-selection template and suggests that in the short-term box turtles may not adapt their predisposed behavior to local conditions. Thus, translocated animals may evaluate and respond to resource cues as if they were at the original site. Lack of site fidelity may result from individuals seeking additional resources to match their resource-selection template. Successful translocation of turtles may require an assessment of resource selection prior to translocation and development of management strategies that mitigate turtle response to translocation. 相似文献
52.
Sampling was conducted on the Missouri and Yellowstone rivers, North Dakota to obtain information on the distribution, abundance and habitat use of the sturgeon chub (Macrhybopsis gelida) and sicklefin chub (M. meeki)(Family Cyprinidae), two declining benthic fish species native to the Missouri River basin. The study area consisted of three distinct river segments, the Missouri River near Williston, the Missouri River near Bismarck (below Garrison Dam), and the Yellowstone River near its confluence with the Missouri River. Both species of chub were collected, mainly with a benthic trawl, throughout 94% of the range sampled in the Williston and Yellowstone segments. Sicklefin and sturgeon chubs were the second and third most abundant cyprinids, respectively, collected from the Williston and Yellowstone segments. Best-fit regression models indicated that the presence of sturgeon chubs increased with decreasing depth, increasing velocity and decreasing water clarity, and that the presence of sicklefin chubs increased with increasing depth, decreasing velocity and decreasing water clarity. In contrast, no chubs of either species were collected in trawls from the Bismarck segment. This segment had significantly deeper, faster, and clearer water than both the Williston and Yellowstone segments. 相似文献
53.
Reproductive condition and occurrence of intersex in bighead carp and silver carp in the Missouri River 总被引:1,自引:0,他引:1
Little is known about the reproductive biology of the exotic bighead carp Hypophthalmichthys nobilis and silver carp Hypophthalmichthys molitrix in the Missouri River. In order to fill this gap in understanding, herein is described the reproductive condition of these
Asian carps. Evidence is presented which indicates that bighead and silver carp in the Missouri River have a protracted spawning
period that extends from early spring through fall and some individual bighead and silver carp are spawning multiple times
during a reproductive season. Although bighead and silver carps are successfully maturing and spawning in the Missouri River
some reproductive abnormalities such as intersex, atresia, and sterility were observed. Knowledge of the reproductive activity
of these invasive carps may be useful to resource managers tasked with their control. Furthermore, the reproductive abnormalities
observed should be considered when evaluating the environmental condition of the Missouri River relative to supporting a healthy
fish fauna. 相似文献
54.
Abstract: Eastern red bats (Lasiurus borealis) have been found to overwinter in areas that can experience severe fluctuations in temperature. We examined the red bat's use of winter roosts in southwest Missouri, USA, for 2 winters (2003–2005). We found tree roosts in eastern red cedars (Juniperus virginiana) and hardwoods. Tree roost sites were located on the south side of trees, and we found roost trees on south-facing slopes. Roost sites occurred more frequently in the location with least canopy cover. Bats switched from tree roosts to leaf litter roosts when ambient temperatures approached or fell below freezing. We found habitat characteristics and aspect to be determining factors in the selection of leaflitter roosts. Management of overwintering red bats requires a diverse forest structure, including canopy gaps, stand-density variation, and leaf-bearing trees, including oaks (Quercus spp.). 相似文献
55.
JOHN H. SCHULZ RONALD A. REITZ STEVEN L. SHERIFF JOSHUA J. MILLSPAUGH 《The Journal of wildlife management》2007,71(2):628-633
ABSTRACT Wildlife managers are becoming more concerned about the exposure of birds, in addition to waterfowl, to spent lead shot. Knowledge of hunter attitudes and their acceptance of nontoxic-shot regulations will be important in establishing new regulations. Our objective was to assess the attitudes of small game hunters in Missouri, USA, toward a nontoxic-shot regulation for small game hunting, specifically for mourning doves (Zenaida macroura). Most hunters (71.7–84.8%) opposed additional nontoxic-shot regulations. Hunters from rural areas, hunters with a rural background, hunters who hunt doves, hunters who currently hunt waterfowl, hunters who primarily use private lands, and current upland game hunters were more likely to oppose new regulations. For mourning dove hunting, most small game hunters (81.1%) opposed further restrictions; however, many non-dove hunters (57.1%) expressed no opinion. Because our results demonstrate that most small game hunters and dove hunters in Missouri are decidedly against further nontoxic-shot regulations, any informational and educational programs developed to accompany future policy changes must address their concerns. 相似文献
56.
植物园在植物科学研究、生物多样性保护和植物资源可持续利用中具有重要作用,也是公众教育和知识传播的重要平台,具有文化传承和历史延续性的功能。以中国科学院华南植物园、英国皇家植物园邱园和美国密苏里植物园为例,从物种保护、科学研究和科学传播3 个方面对植物园进行了全面的比较和分析,为华南植物园未来发展提出了一些建议,可为华南植物园乃至我国植物园的发展提供参考依据。 相似文献
57.
58.
Augmentation of murine immune responses by amphotericin B. 总被引:4,自引:0,他引:4
Immunostimulant effects have been demonstrated in mice following single injections of amphotericin B or amphotericin methyl ester. Augmentation of both humoral and cell-mediated immune responses helps to explain the beneficial therapeutic effects observed in human and murine neoplasms after administration of amphotericin. Relevant to its immunological adjuvant properties, amphotericin produces striking reversible changes in murine thymus and splenic weights and in lymphoid organ histology. The chemical purity, nonimmunogenicity, and permissible toxicity of amphotericin recommend it as a model for the study of the cellular and molecular mechanisms of immunological adjuvants. 相似文献
59.
R P MacDermott G S Nash M J Bertovich N S Merkel I J Weinrieb 《Cellular immunology》1978,38(1):198-202
The mitogenic potential of normal human peripheral blood lymphocyte subpopulations in response to the plant lectins phytohemagglutin, erythroaggluting phytohemagglutinin, leukoagglutinating phytohemagglutinin, and pokeweed mitogen has been examined. Doubly purified B-, Null, and T-cell fractions were used by themselves and in conjunction with small percentages (1 to 10%) of other subpopulations. Purified human B and Null cells were found to be nonreactive. However, when incubated with as little as 1% T cells, significant mitogenic responsiveness by B and Null cells was observed. This helper effect was apparent with both normal and irradiated T cells. It would thus appear that mitogenic responsiveness of unseparated mononuclear cells is predominantly a function of T cells either as responding cells or as necessary helper cells. 相似文献
60.
H G Wilcox G D Dunn M Heimberg 《Biochemical and biophysical research communications》1976,73(3):733-740
Palmitic acid (16:0) and palmitoleic acid (16:1), as the complex with bovine serum albumin, were infused at rates of 62 and 124 μmoles/hr into an albumin-buffer medium perfusing livers isolated from normal fed male rats. In other experiments, equimolar mixtures (124 μmoles/hr, total) of 16:0 + 16:1, or myristate (14:0) + 16:1 were infused. The output of triglyceride when 16:1 was infused was greater than when equivalent amounts of 14:0 or 16:0 were infused; output with equimolar mixtures of 14:0 and 16:1, or 16:0 and 16:1 was intermediate between that of saturated and unsaturated fatty acids alone. Rate-zonal mobility of the VLDL in the ultracentrifuge was more rapid as the quantity of 16:1 available to the liver increased, but did not change with increasing amounts of 16:0. The rate-zonal mobility of the mixtures of 14:0 and 16:1, or of 16:0 and 16:1, was not different than that of 16:1 alone. The ratios of phospholipid and cholesterol relative to triglyceride in the VLDL decreased with increasing output of triglyceride and with unsaturation of the fatty acid. Ratios resulting from mixtures of the fatty acids appeared to be in an intermediate position. The composition and properties of the secreted VLDL clearly are dependent on the structure and quantity of FFA available to the liver; with mixtures of saturated and unsaturated fatty acids, the unsaturated fatty acid seems to exert a dominant effect. 相似文献