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1.

Feather samples gathered from the mantle of breeding birds of the three New Zealand species of oystercatcher were analysed spectrophotometrically to evaluate melanin pigmentation parameters. The only statistically significant difference in these parameters was among individuals, indicating that melanin pigmentation is a conservative character of little systematic value. There is no evidence for geographic variation in melanin pigmentation of black phase Haematopus unicolor, and thus there is no justification for considering southern black birds specifically distinct from their northern counterparts on the basis of dorsal plumage colour.  相似文献   
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《Ostrich》2013,84(3):281-284
Golden Nightjar Caprimulgus eximius is an apparently sedentary sub-Saharan species with a breeding range extending from Senegal and Mauritania to Sudan. Although genetic studies of nightjars and related Caprimulgiformes have been published previously, none has included Golden Nightjar. In this study, mitochondrial and nuclear DNA of a Golden Nightjar found dead in Western Sahara in April 2016 was sequenced and compared with other species in the genus Caprimulgus. It was concluded with strong support that Golden Nightjar is closely related to Egyptian Nightjar C. aegyptius. It is hypothesised that Golden and Egyptian Nightjars may have arisen by splitting of a single ancestral species into migratory and sedentary populations.  相似文献   
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An experiment was conducted in two gorse populations (Ulex europaeus) in which Chondrostereum purpureum was applied each month as mycelial-agar cultures to the wounds of decapitated stems of previously untreated gorse plants to determine its potential as a mycoherbicide. Summer-autumn (Feb-May) or late winter-early spring (Aug-Sept) applications were effective in both populations, halving stem stump survival (from an average of 56 to 29%). Another experiment in the same gorse populations evaluated the combined effects of C. purpureum applied in May to decapitated stems, and Fusarium tumidum applied as spores in an invert emulsion to regenerative shoots 5-6 months later. There was no evidence of synergism between the two fungi; each pathogen independently reduced the density of regenerative shoots on the decapitated stems by 39-63% averaged over the 12 months following their respective applications. It is concluded that both pathogens have potential as mycoherbicides for gorse regenerating after stem decapitation.  相似文献   
5.
We examined seasonal changes in microhabitat use by the murid rodents Akodon azarae and Calomys laucha in agroecosystems of the former pampa region of Argentina. In summer, trap data showed that both species had low densities and were almost equally distributed between the mature cropfields and their surrounding weedy borders. Analysis of vegetation at the trap sites revealed no selection for microhabitats at the borders, whereas in the cropfields both species shared preferences for covered microhabitats. In contrast, winter data revealed a sharp habitat segregation, being Calomys numerically dominant in post-harvest cropfields and Akodon more abundant in borders. Moreover, there were clear differences in microhabitat selection at the borders, A. azarae occupying the more covered microhabitats and C. laucha the less covered. Breadth and overlap of niches were calculated using principal component analysis, in order to recognize interspecific competition and its influence on community niche space. Available evidence indicates that the structure of this rodent community is strongly influenced by seasonal changes in habitat stucture and rodent abundance. The socially dominant A. azarae retains the best part of the available niche space, a fact becoming more evident under the harsh winter conditions.  相似文献   
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The major histocompatability complex (MHC) is a multigene family of receptors that bind and present antigenic peptides to T-cells. Genes of the MHC are characterized by an outstanding genetic polymorphism, which is considered to be maintained by positive selection. Sites involved in peptide binding form binding pockets (P) that are collectively termed the peptide-binding region (PBR). In this study, we examined the level of MHC genetic diversity within and among natural populations of brown hare ( Lepus europaeus ) from Europe and Anatolia choosing for analysis of the second exon of the DQA locus, one of the most polymorphic class II loci. We aimed at an integrated population genetic analysis of L. europeaus by (i) correlating MHC polymorphism to genetic variability and phylogenetic status estimated previously from maternally (mtDNA) and biparentally (allozymes, microsatellites) inherited loci; and (ii) comparing full-length exon amino acid polymorphism with functional polymorphism in the PBR and the binding pockets P1, P6 and P9. A substantial level of DQA exon 2 polymorphism was detected with two completely different set of alleles between the Anatolian and European populations. However, the phylogeny of full-length exon 2 Leeu-DQA alleles did not show a strong phylogeographic signal. The presence of balancing selection was supported by a statistically significant excess of nonsynonymous substitutions over synonymous in the PBR and a trans-species pattern of evolution detected after phylogenetic reconstruction. The differentiating patterns detected between genetic and functional polymorphism, i.e. the number and the distribution of pocket variants within and among populations, indicated a hierarchical action of selection pressures.  相似文献   
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楚德昌 《四川动物》2001,20(4):217-219
对47只冬眠季冬眠阵低温期刺猬的小肠与53只非冬眠季刺猬的小肠,在11.5℃和37℃及离体条件下的收缩强度进行比较,和在37℃条件下对肾上腺素(Ad)、乙酰胆硷(Ach)、心得安(Propranolol)、阿托品(Atr)反应进行比较,表明在11.5℃条件下,冬眠与非冬眠刺猬离体小肠都基本无运动机能,在37℃条件下,冬眠季冬眠阵低温期刺猬离体小肠运动强度明显高于非冬眠季、Ad、Ach、Propranolol、Atr使冬眠季冬眠阵低温期刺猬离体小肠收缩强度变化率明显高于非冬眠季。  相似文献   
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The breeding biology of a recently (1974) introduced hedgehog Erinaceus europaeus population was studied on a large Scottish island. These hedgehogs have caused serious declines in internationally important ground-nesting shorebirds, and population control is now being attempted. Sexual behaviour commenced in late April, a few days after the main emergence from hibernation. It peaked in mid-May and again in late June/early July, and ceased by mid-August. Females were promiscuous and were estimated to have sexual encounters (although not necessarily matings) with at least five males during the main mating period. Two-thirds of females attempted to breed for the first time in their second calendar year (i.e. as sub-adults), and the rest in their third calendar year (i.e. as adults). At least 96% ( n =27) of adult females attempted to breed in the early part of the season (litters born in June). The vast majority (81%, n =26) bred again in the later part of the season (litters born after mid-July). Breeding success (≥1 young emerged) was relatively high. For adults, 63% ( n =24) of early-season and 86% ( n =18) of late-season attempts were successful. For sub-adult females the figure was 62% ( n =9). The annual mean productivity per female was estimated at 4.04 young for adults and 0.85 young for sub-adults. The implications of these results for the effectiveness, timing and welfare aspects of hedgehog control programmes are discussed.  相似文献   
10.
Techniques for assessing the abundance of Brown Hares Lepus europaeus   总被引:1,自引:0,他引:1  
Over the last few decades, there have been significant declines in Brown Hare Lepus europaeus numbers throughout Europe, leading to concern for their status in many countries. In Britain, there were no quantified data on the extent of this decline, on current population levels, or any baseline against which to monitor future population changes. The need for a quantified national hare survey led to this evaluation of the techniques available to assess hare numbers. Published information on counting hares is reviewed, and various techniques compared by applying them to a number of sites in southern England. Three basic approaches are available: counts of inactive hares, counts of active hares and indirect methods. Counts of inactive hares include total clearance, wide belt and line transect counts. Total clearance counts give an absolute figure, but are labour intensive and can only be applied to restricted areas. Wide-belt assessments are difficult to apply in certain habitats and even in open areas tend to produce a substantial over-estimate. Line transect counts are easy to undertake and are not labour intensive but should only be applied to large areas, or data from several small areas combined. Counts based on active hares are more problematical, because it is difficult to determine what proportion of the population is inactive at any one time. Spotlight counts based on variable circular plots are the most accurate but difficult to apply widely, and twilight counts are very subjective in their interpretation, especially when surveying small areas or areas with a large proportion of concealing habitats. Of the indirect methods, dung pellet counts can be valuable in specific areas but are difficult to apply across a range of habitats. We concluded that, of the various techniques considered, line transect counts have the greatest potential for a national survey, but need to be stratified so that enough transects are undertaken within each habitat stratum to obtain a reliable mean population estimate for each stratum.  相似文献   
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