农田黑线姬鼠与臭鼩的巢区及种间关系的研究

通过为期一年的标志重捕研究,获得了农田优势种黑线姬鼠与臭聃的巢区、活动距离、领域性等资料,分析了种间领域性及空间分布的关系。并观察到随着捕获突数增多,对动物的可捕性产生影响,再结合对重捕期体重变化的分析,发现长期标志重捕对两种动物产生了正与负的效应。     

Larval Chigger Mites Collected from Small Mammals in 3 Provinces,Korea

A total of 9,281 larval chigger mites were collected from small mammals captured at Hwaseong-gun, Gyeonggi-do (Province) (2,754 mites from 30 small mammals), Asan city, Chungcheongnam-do (3,358 mites from 48 mammals), and Jangseong-gun, Jeollanam-do (3,169 for 62 mammals) from April-November 2009 in the Republic of Korea (= Korea) and were identified to species. Leptotrombidium pallidum was the predominant species in Hwaseong (95.8%) and Asan (61.2%), while Leptotrombidium scutellare was the predominant species collected from Jangseong (80.1%). Overall, larval chigger mite indices decreased from April (27.3) to June (4.9), then increased in September (95.2) and to a high level in November (169.3). These data suggest that L. pallidum and L. scutellare are the primary vectors of scrub typhus throughout their range in Korea. While other species of larval chigger mites were also collected with some implications in the transmission of Orientia tsutsugamushi, they only accounted for 11.2% of all larval chigger mites collected from small mammals.     

Reproductive skew, costs, and benefits of cooperative breeding in female wood mice (Apodemus sylvaticus)

Two current models seek to explain reproduction of subordinatesin social groups: incentives given by dominants for peacefullyremaining in the group (reproductive skew model) or incompletecontrol by dominants. These models make different predictionsconcerning genetic relatedness between individuals for thedistribution of reproduction and the stability of cooperativebreeding associations. To test these models and to furtherexplore the relationships between reproductive skew, geneticrelatedness, and investment of each participant, we performedbehavioral observations of female wood mice (Apodemus sylvaticus)raising pups communally. Our results do not support previousmodels. Differences in lifetime reproductive success were significantlygreater within mother—daughter pairs than within pairsof sisters or unrelated females. Subordinate females of eitherbreeding unit did not differ in their direct reproduction.Calculations of inclusive fitness based on our results leadto the following predictions: (1) Communal nests should occuronly when ecological circumstances prevent solitary breeding.(2) Subordinate females gain the highest inclusive fitnessjoining their mothers; they also show the highest nursing investment.(3) Mothers should accept daughters, who have no opportunityfor solitary breeding. (4) Dominant sisters and unrelated femalesshould reject subordinate females because cooperative breedingreduces their reproductive success. However, breeding unitsof dominant sisters and unrelated females nevertheless occurand can be explained by our finding that such females significantlyreduce nursing time, which may help them save energy for futurebreeding cycles. Our data demonstrate that both genetic relatednessand investment skew are important in the complex evolutionof reproductive skew in cooperative breeding.     

蜂桶寨自然保护区中华姬鼠及社鼠肥满度的年龄和季节变化

肥满度被广泛用于动物生长状况与环境、生存、繁殖等方面的研究。为揭示横断山脉森林环境中中华姬鼠（Apodemus draco）和社鼠（Niviventer confucianus）肥满度的变化规律及影响原因,我们于2008年4~11月对四川省蜂桶寨国家级自然保护区内中华姬鼠和社鼠肥满度在各年龄组及不同季节中的变化进行了研究。结果显示,中华姬鼠肥满度在各年龄组间的差异显著,其变化趋势为老年组>成年组>亚成年组>幼年组;亚成年组及老年组肥满度在各季节间无显著差异,而在成年组则差异明显,以春季中最高。社鼠肥满度在各年龄组间无显著性差异;亚成年组肥满度在各季节间差异显著,在夏秋季中最低,同时成年组及老年组肥满度在季节间无显著差异。中华姬鼠和社鼠亚成年组、成年组及老年组肥满度与海拔无显著的线性关系。分析认为,中华姬鼠老年组个体可能在应对外界环境方面要强于幼年个体而具有最高的肥满度,成年个体肥满度的季节变化可能受食物资源季节差异和繁殖能量需求的影响;社鼠成年及老年个体能通过相应的季节性调节维持肥满度的稳定,而亚成年个体在调节方面较弱,故其肥满度在夏秋季最低。     

蜂桶寨自然保护区中华姬鼠和社鼠肥满度的研究

我们于2008年4~11月对四川蜂桶寨自然保护区内中华姬鼠(Apodemus draco)和社鼠(Niviventer confucianus)肥满度在各年龄组及不同季节中的变化进行了研究,并初步分析了影响因素。结果显示：中华姬鼠肥满度在各年龄组中的性别差异不明显;在各年龄组间的差异显著,其变化趋势为老年组＞成年组＞亚成年组＞幼年组,亚成年组及老年组肥满度在各季节间无显著差异,而成年组则差异明显。社鼠肥满度在各年龄组间无显著性差异,亚成年组肥满度在各季节间差异显著,同时成年组及老年组肥满度在季节间无显著差异;二物种,亚成年组、成年组及老年组肥满度与海拔无明显的线性关系。分析认为,繁殖期能量的消耗的增加可能导致中华姬鼠肥满度在繁殖期下降,而社鼠成年及老年个体面对食物资源、能量需求等方面的季节变化,能够通过相应的调节,维持肥满度的稳定。     

The effects of habitat and spatial features of wetland fragments on the abundance of two rallid species with different degrees of habitat specialization

The management of wild gamebirds for shooting involves a combination of habitat management (woodland, field boundaries and game crops), winter feeding and control of potential nest predators, any of which could benefit other birds, including nationally declining species associated with farmland habitats. Changes in numbers of passerines were monitored over six years in relation to game management on farmland in Leicestershire. Nest success was monitored over four years and, for some species, was inversely related to abundance of breeding corvids. Abundance of breeding passerines increased during the period of game management. Species whose breeding populations have declined nationally (coincident with agricultural intensification) showed the greatest increases in abundance relative both to other species, and to the same nationally declining species in nearby farmland. The precise mechanism by which the game management package contributes to increased breeding numbers is not understood and is likely to differ between species. However, these results show that further integration of wild game management into farming systems could have conservation benefits for nationally declining farmland birds.     

Predation of annual grass weed seeds in arable field margins

Seeds of three species of annual grass weeds (Alopecurus myosuroides, Avena fatua and Bromus sterilis) were placed in field margins around arable fields in a randomised block split-plot design experiment. The field margin vegetation was either sown or naturally regenerated and either cut or uncut. The seeds were either placed in cages designed to exclude small mammals and birds or were uncaged. The proportion of seeds removed was monitored on 10 occasions and mean seed loss was analysed. In general, a greater proportion of weed seeds was removed from uncaged trays in uncut swards, suggesting predation by small mammals, which inhabit tall grass. This effect was mainly due to removal of seeds of the two large-seeded species (A. fatua and B. sterilis), with A. fatua being especially favoured. It is therefore likely that small mammals play a role in the population dynamics of major crop weeds by feeding on their seeds in field margins, especially when these are dense and uncut.     

安徽淮北农区三种鼠的种群数量动态与年龄结构的关系

本文对安徽省淮北农业区的黑线姬鼠、大仓鼠和黑线仓鼠的种群数量及与年龄组成变化的关系进行探讨。结果表明,其各鼠的年龄组成在每年的不同时段内的变化有一定的规律:各鼠主要繁殖群体的年龄组也是有区别的,如黑线姬鼠和黑线仓鼠主要是成年Ⅱ组,大仓鼠主要是成年Ⅰ组。如果种群中幼年组+亚成年组+成年Ⅰ组的比例高时,则当年数量就可能较高,如果种群中成年Ⅱ组和老年组的比例较高时,当年数量则低。     

三种姬鼠的染色体比较研究

本文采用染色体分带技术（Ｇ－,Ｃ－带和银染色）,对中华姬鼠（Ａｐｏｄｅｍｕｓｄｒａｃｏ）、大林姬鼠（Ａ．ｐｅｎｉｎｓｕｌａｅ）和大耳姬鼠（Ａ．ｌａｔｒｏｎｕｍ）的核型进行了观察分析。结果表明：３种姬鼠的２ｎ均为４８。中华姬鼠的染色体均为端着丝点染色体。大林姬鼠的常规核型中,除１对中着丝点染色体（Ｎｏ．２３）外,其余均为端着丝点染色体。大耳姬鼠的核型中,有１３对端着丝点染色体,２对亚端着丝点染色体,１对亚中着丝点染色体和７对中着丝点染色体。中华姬鼠Ｃ－带核型中,所有染色体着丝点Ｃ－带都呈强阳性,异染色质非常丰富,Ｙ染色体整条深染。在大林姬鼠Ｃ－带核型中,Ｎｏｓ．７,１１,１５,２１,２２着丝点Ｃ－带弱化甚至近阴性,其余染色体着丝点异染色质Ｃ－带都呈现程度不同的阳性。且Ｎｏｓ．２,４,７有强弱不同的端位异染色质带。Ｘ染色体着丝点区有大块的异染色质斑带出现,Ｙ染色体整条深染。大耳姬鼠除Ｎｏｓ．３,４,１０,１２,１３染色体着丝点Ｃ－带很弱外,其余染色体着丝点Ｃ－带均呈阳性,并有８对（Ｎｏｓ．１６－２３）染色体出现异染色质短臂。从总体上看,大林姬鼠和大耳姬鼠的着丝点异染色质明显比中华姬鼠的少。中华姬鼠的Ａｇ－ＮＯＲ     

Allelic diversity at the Mhc-DQA locus of woodmouse populations (Apodemus sylvaticus) present in the islands and mainland of the northern Mediterranean

Aim Polymorphism at neutral markers and at MHC loci in rodent populations living on islands is generally low. The main genetic factors that may contribute to a reduced level of genetic variability are genetic drift, reduced gene flow and founder events. We investigated the pattern of polymorphism at the second exon of the Mhc‐DQA gene in island populations of Apodemus sylvaticus and in their mainland counterparts to investigate the pattern of MHC polymorphism in a phylogeographical context and to assess the impact of insularity on diversity at this locus. Location Eight north Mediterranean populations of Apodemus sylvaticus were studied, including five island populations (Majorca, Minorca, Porquerolles, Port‐Cros and Sicily) and three mainland populations. Methods cDNA sequencing and nucleotide sequences analyses. Synonymous and non‐synonymous substitutions were examined at the PBR and non‐PBR sites. The DQA allelic distribution in populations was compared with the woodmouse phylogeography. Results This study presents novel DQA alleles. High polymorphism of the DQA locus is recorded in natural populations of A. sylvaticus with 13 alleles being widely distributed irrespective of the geographical origin and palaeoclimatic history of populations. The DQA locus does not show the expected pattern for non‐synonymous substitutions at the PBR sites. However, island populations show a weak loss of polymorphism in comparison with their mainland counterparts. Main conclusions The DQA locus in the woodmouse seems to be subject to weak selection and does not allow resolution of phylogeographical relationships among European woodmouse populations. The presence of at least three alleles in island populations and the maintenance of five alleles between the two European lineages over 1.5 Myr suggest that balancing selection may act within populations, and more precisely within island populations, to maintain genetic variability. This study shows that phylogeographical studies are a prerequisite for any genetic investigation of selected genes in natural populations.