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1.
杨月伟  刘震  刘季科 《生态学报》2007,27(10):3983-3992
在野外围栏条件下,采用重复的2×2×2析因实验设计,测定食物、捕食和竞争物种黑线姬鼠对东方田鼠攻击行为作用的格局。东方田鼠各处理种群攻击水平与其种群密度的相关甚为复杂,与Chitty多态行为假设的预测不一致。东方田鼠双冲突个体间的攻击水平与其体重的相关不显著,而与冲突个体的体重差异则呈显著的负相关,体重差异越大,冲突个体间的攻击水平越低。雄体攻击水平与其繁殖特征无显著的相关关系,而雌体间攻击水平则受繁殖状态的影响,动情雌体间的攻击水平显著地高于非动情雌体。体重差异和食物对雄体的攻击行为具有极显著的独立作用,捕食和种间竞争对雄体攻击行为的独立作用不显著,而捕食与种间竞争交互作用对雄体攻击行为的效应则达到显著水平。体重差异、食物、捕食和种间竞争对动情雌体的攻击水平均有极显著的独立作用,3类外部因子交互作用的效应达到极显著水平;而3类外部因子交互作用对非动情雌体攻击行为的效应则不显著。结果检验了外部因子食物、捕食、种间竞争对田鼠类动物种群攻击行为具有独立和累加的整合效应的假设。  相似文献   

2.
杨月伟  刘震  刘季科 《生态学报》2007,27(10):3983-3992
在野外围栏条件下,采用重复的2×2×2析因实验设计,测定食物、捕食和竞争物种黑线姬鼠对东方田鼠攻击行为作用的格局。东方田鼠各处理种群攻击水平与其种群密度的相关甚为复杂,与Chitty多态行为假设的预测不一致。东方田鼠双冲突个体间的攻击水平与其体重的相关不显著,而与冲突个体的体重差异则呈显著的负相关,体重差异越大,冲突个体间的攻击水平越低。雄体攻击水平与其繁殖特征无显著的相关关系,而雌体间攻击水平则受繁殖状态的影响,动情雌体间的攻击水平显著地高于非动情雌体。体重差异和食物对雄体的攻击行为具有极显著的独立作用,捕食和种间竞争对雄体攻击行为的独立作用不显著,而捕食与种间竞争交互作用对雄体攻击行为的效应则达到显著水平。体重差异、食物、捕食和种间竞争对动情雌体的攻击水平均有极显著的独立作用,3类外部因子交互作用的效应达到极显著水平;而3类外部因子交互作用对非动情雌体攻击行为的效应则不显著。结果检验了外部因子食物、捕食、种间竞争对田鼠类动物种群攻击行为具有独立和累加的整合效应的假设。  相似文献   

3.
种群外部及内部因子对东方田鼠巢区大小的效应   总被引:3,自引:0,他引:3  
杨月伟  刘季科  刘震 《动物学报》2005,51(2):205-214
在野外围栏条件下, 采用重复的2×2×2析因实验, 测定外部和内部因子对东方田鼠(Microtus fortis)巢区大小的作用模式。研究结果表明, 雄体巢区大小显著大于雌体巢区大小。雄体巢区大小与体重存在显著的正相关, 而雌体巢区大小与体重的相关不显著; 雄体和雌体巢区大小与种群数量均呈显著的线性负相关。外部因子对东方田鼠雄体和雌体巢区大小的作用不一致。在排除内部因子种群数量及体重对雄体巢区大小作用的条件下, 食物对雄体巢区大小的作用显著; 而捕食及种间竞争的独立作用及其交互作用, 以及3 种外部因子的交互作用均不显著; 在排除种群数量对巢区大小作用的条件下, 食物与捕食的独立作用及3 种外部因子的交互作用对雌体巢区大小的效应均达到显著水平, 食物与种间竞争的交互作用接近显著, 而种间竞争的独立作用、食物和捕食的交互作用, 以及捕食与种间竞争的交互作用对雌体巢区大小的效应均不显著。本文结果验证了种群外部因子食物、捕食及种间竞争、种群内部因子种群数量及个体体重对田鼠种群巢区大小具有独立和交互作用的假设。  相似文献   

4.
杨月伟  刘季科  刘震 《生态学报》2005,25(6):1523-1528
在野外围栏条件下,采用2×2×2析因实验,测定外部因子食物、捕食,以及同域分布物种黑线姬鼠的种间竞争对东方田鼠扩散和活动距离的独立作用及其交互作用的效应。研究结果表明,在所有的扩散个体中,幼体扩散的比例为71.0%。雄体扩散的比例为80.5%。东方田鼠扩散的趋势与其种群密度及补充量的变动一致。食物对扩散具有显著独立作用;捕食对扩散的作用接近显著;种间竞争对扩散的直接效应不显著;食物、捕食与种间竞争交互作用对扩散的效应亦不显著。在诱捕期内雄性的长距离活动比例及其诱捕期间长距离活动比例均显著大于诱捕期内雌性及其诱捕期间的长距离活动比例。不同处理种群间,仅雄体在诱捕期间的长距离活动比例具有显著差异;食物对雄体的长距离活动具有直接和间接(通过密度)的效应;而预防捕食者和竞争物种对不同处理种群雄体的长距离活动则无一致的效应。  相似文献   

5.
在捕食和附加食物交互作用条件下,以恐吓、进攻、追逐、争斗及回避5类行为为变量,以恐吓、进攻、追逐计数之和的平均值作为攻击水平,测定根田鼠种群不同波动时期成体的攻击水平.发现根田鼠的攻击性与种群波动时期之间,存在明显的关联.统计分析结果表明,在种群3个波动时期,4种处理种群两性攻击型个体比例差异显著.除预防捕食者无附加食物(-P,-F)种群的雌体外,其它处理种群增长期和高峰期雌性和雄性攻击型个体的比例高于其衰减期.其中,预防捕食者附加食物(-P,+F)种群、-P,-F种群及未预防捕食者附加食物(+P,+F)种群,雄性攻击型个体的比例均为增长期>高峰期>衰减期;在未预防捕食者无附加食物(+P,-F)种群,雄性攻击型个体比例为高峰期>增长期>衰减期.各处理种群雌性攻击型个体比例的格局与雄体的不同.其中,-P,+F种群及+P,+F种群为增长期>高峰期>衰减期,+P,-F种群为高峰期>增长期>衰减期,而-P,-F种群攻击型个体比例为高峰期>衰减期>增长期.虽不同处理种群雌体及雄体的5类行为变量与种群密度的相关性不一致,而具有明显攻击性的恐吓、进攻及争斗3类行为则分别与种群密度呈显著或极显著的线性正相关关系,其结果与Chitty多态行为假设预测的一致;验证了所提出的特定假设:种群外部因子捕食和食物交互效应介导的攻击行为选择,是引起田鼠类种群季节性波动的主要内部因子.  相似文献   

6.
本项研究在野外围栏条件下,采用析因实验设计,测定食物可利用性和捕食对根田鼠(Microtusoeconomus)种群空间行为的作用模式。检验的特定假设为,高质量食物较大的可利用性能降低田鼠的攻击行为和活动;捕食能减少田鼠的活动。研究结果表明,食物可利用性能间接地和直接地影响根田鼠的空间行为。附加食物种群具有较高的密度和较小的巢区,且在诱捕期间具有较少的长距离活动和较低的攻击水平。捕食者的存在不直接影响攻击行为,但能影响诱捕期间的长距离活动,此为根田鼠对捕食者存在作出的直接反应。在阐明田鼠种群动态时,应仔细考虑上述因子相互作用的效应。  相似文献   

7.
本研究在野外围栏条件下采用析因实验设计,测定营养、捕食及空间行为对根田鼠(Mi-crotusoeconomus)种群统计特征的影响。本文旨在检验下述特定假设:高质量食物可利用性和捕食对限制小型啮齿动物种群密度具有独立的和累加的效应。3年期间,4种野外实验处理6个重复的研究结果表明,附加食物并预防捕食者处理的种群具有最高密度;未附加食物及不预防捕食者处理(对照)的种群密度最低;而单一处理的种群,其密度居中。不同处理条件下,新生个体在种群的补充模式以及种群瞬时增长率的变化均与种群密度的变动相应一致。双因素ANOVA的结果证明,附加高质量食物能明显地提高根田鼠的种群密度,而对种群补充量的作用则较弱,仅接近显著水平;预防捕食者不仅能显著地作用于种群密度,更能强烈地影响种群补充量。高质量食物和捕食者的作用具有累加的性质,两者的交互作用对种群密度和补充量均无显著影响。  相似文献   

8.
在自然界,捕食者和寄生物是两种主要的种群外部调节因子,二者的交互作用会对猎物和宿主种群波动产生深远影响。较低的球虫感染强度与捕食对根田鼠(Alexandromys oeconomus)繁殖无显著的交互作用。自然界球虫感染存在季节性变化,秋季感染强度最高。为了探究较高感染强度下,球虫与捕食对根田鼠繁殖的主效应及交互作用,本研究采用2×2析因实验设计,在野外围栏中测定了根田鼠种群肠道内寄生物的感染率和感染强度、雄性睾丸指数、睾酮水平、精子密度、精子活力以及雌性卵巢指数。结果表明,较高的感染强度下,球虫能显著抑制根田鼠的繁殖性能,但球虫感染与捕食对根田鼠的繁殖无显著的交互作用,这可能与球虫感染和捕食效应在时间上的错配有关。本研究认为,球虫感染对繁殖期小哺乳动物种群的调节作用虽有限,但其可通过与捕食者的耦合来降低宿主越冬时的存活率,进而影响宿主种群波动。  相似文献   

9.
本项研究在野外围栏条件下,采用析因实验设计,测定食物可利用性和捕食对根田鼠种群空间行为的作用模式。检验的特定假设为,高质量食物较大的可利用性能降低田鼠的攻击行为和活动,捕食能减少田鼠的活动。研究结果表明,食物可利用性能间接地和直接地影响根田鼠的空间行为,附加食物种群具有较高的密度和较小的巢区,且在诱捕期间具有较少的长距离活动和较低的攻击水平。捕食者的存在不直接影响攻击行为,但能影响诱捕期间的长距离  相似文献   

10.
根田鼠攻击行为模式及其进化稳定对策分析   总被引:6,自引:1,他引:5  
聂海燕  刘季科 《生态学报》2004,24(7):1406-1412
在捕食和附加食物交互作用条件下 ,测定根田鼠种群攻击水平与种群参数之间的关系 ,应用对策论分析攻击行为的模式。通过观测 1 6 5对实验个体的攻击行为 ,发现体重和繁殖特征决定根田鼠个体的攻击水平。体重较大个体及繁殖个体的攻击频次最高。攻击水平的性别差异显著。Kruskal- Wallis单侧秩方差检验结果表明 ,雄体攻击水平显著高于雌体。攻击水平与种群密度呈负相关关系 ,但不显著。与留居个体比较 ,扩散个体的攻击性弱。高质量的附加食物可降低根田鼠的攻击水平 ,捕食者的存在不直接影响攻击水平。根田鼠的攻击行为属仪式化非伤害行为。ESS的鹰 -鸽对策模型分析结果与实验结果一致 :不同处理种群 ESS集的鹰型对策者比例有显著差异 ,环境条件愈差 ,取胜的价值愈大 ,种群中鹰型对策者比例愈高。有捕食者、无附加食物( P,- F)种群的环境条件最差 ,鹰型对策者比例最高 ,为 0 .4 0 ;次为无捕食者、无附加食物 (- P,- F)种群 ,为 0 .33;有捕食者、有附加食物 ( P, F)种群 ,为 0 .1 8;无捕食者、有附加食物 (- P, F)种群的环境条件最优越 ,鹰型对策者比例最低 ,为0 .1 7。验证了捕食和食物交互效应能改变田鼠类动物攻击行为格局及对策模式的假设  相似文献   

11.
Haiyan Nie  Jike Liu 《Oikos》2005,109(2):387-395
This paper reports the effects of food supply, predation and the interaction between them on the population dynamics of root voles, Microtus oeconomus , by adopting factorial experiments in field enclosures. This two-factor experiment proved the general hypothesis that food supply and predation had independent and additive effects on population dynamics of root voles. The experimental results proved the following predictions: (1) predation reduced population density and recruitment significantly; (2) food supply increased population density; (3) predation and food supply influenced spacing behavior of root voles separately and additively: Exposure to predation reduced long movements of root voles between trapping sessions; additional food supply reduced aggression level and home range size of root voles. Less movement of individuals that exposed to predators possibly reduced their opportunity of obtaining food and lessened population survival rate, which led population density to decrease. Smaller home range and lower aggression level could make higher population density tolerable. The interactive effect of predation and food on home range size was highly significant (P=0.0082<0.01). The interactive effect of food and predation on dispersal rate was significant (P<0.01). From the experimental results, we conclude that the external factors (predation, food supply) were more effective than internal factors (spacing behavior) in determining population density of root voles – under the most favorable external conditions (−P, +F treatment), the mean density and mean recruitment of root vole population was the highest; under the most unfavorable external conditions (+P, −F treatment), the mean density and mean recruitment of root vole population was the lowest.  相似文献   

12.
小型哺乳动物种群周期性波动的外因调节假说   总被引:1,自引:0,他引:1  
张志强  王德华 《生态学报》2004,24(6):1279-1286
对小型哺乳动物种群数量周期性波动的外因调节假说进行介绍 ,概述了食物假说、捕食假说和复合因子假说的主要内容和研究进展。在少数生存环境严酷的小型哺乳动物种群中 ,食物假说能解释它们的周期性数量波动现象 ,可能作为调节因子起作用 ,但难以说明低数量期的确切机制 ,对于大多数小型哺乳动物而言 ,它更可能作为限制因子。捕食假说解释了北欧芬诺斯坎底亚地区某些种群的周期性波动 ,尤其是捕食的间接效应已引起许多学者的关注 ,但也有不支持该假说的证据。对于复合因子假说 ,近年颇受学者重视 ,其中验证食物和捕食交互及累加作用的实验证据较多 ,有的研究还包括气候、种间竞争、空间或社会行为等因素。有关复合因子的实验研究 ,尽管工作是困难和艰巨的 ,花费也是巨大的 ,但所得结果却极有价值 ,为深入理解种群动态调节理论提供了一个合理而有效的手段  相似文献   

13.
Summary Ecological and temporal aspects of the occurrence and dispersion patterns in three reed warbler species were examined. This provided insight into their intra-and interspecific territoriality. Seasonal changes in the occurrence of territorial males in a reed bed along a gradient from the shore landward were studied. The results demonstrate that intra- and interspecific spacing depends on interspecific dominance and/or ecological constraints. In this case it was shown that there is competition for common habitats between reed warblers and great reed warblers, whereas the moustached warbler is ecologically segregated. The reasons for these dispersal patterns are discussed. They do not appear to enhance the availability of food resources. It seems more likely that territorial spacing might function to reduce nest predation.  相似文献   

14.
Although competition and predation are considered to be among the most important biotic processes influencing the distribution and abundance of species in space and time, the relative and interactive roles of these processes in communities comprised of cyclically fluctuating populations of small mammals are not well known. We examined these processes in and among populations of field voles, sibling voles, bank voles and common shrews in western Finland, using spatially replicated trapping data collected four times a year during two vole cycles (1987–1990 and 1997–1999). Populations of the four species exhibited relatively strong interspecific temporal synchrony in their multiannual fluctuations. During peak phases, we observed slight deviations from close temporal synchrony: field vole densities peaked at least two months earlier than those of either sibling voles or bank voles, while densities of common shrews peaked even earlier. The growth rates of all four coexisting small mammal species were best explained by their own current densities. The growth rate of bank vole populations was negatively related to increasing densities of field voles in the increase phase of the vole cycle. Apart from this, no negative effects of interspecific density, direct or delayed, were observed among the vole species. The growth rates of common shrew populations were negatively related to increasing total rodent (including water voles and harvest mice) densities in the peak phase of the vole cycle. Sibling voles appeared not to be competitively superior to field voles on a population level, as neither of these Microtus voles increased disproportionately in abundance as total rodent density increased. We suggest that interspecific competition among the vole species may occur, but only briefly, during the autumn of peak years, when the total available amount of rodent habitat becomes markedly reduced following agricultural practices. Our results nonetheless indicate that interspecific competition is not a strong determinant of the structure of communities comprised of species exhibiting cyclic dynamics. We suggest that external factors, namely predation and shortage of food, limit densities of vole populations below levels where interspecific competition occurs. Common shrews, however, appear to suffer from asymmetric space competition with rodents at peak densities of voles; this may be viewed as a synchronizing effect.  相似文献   

15.
Interspecific competition is assumed to generate negative effects on coexisting species, possibly including slower population growth and lower survival. The field vole ( Microtus agrestis ) and the sibling vole ( M. rossiaemeridionalis ) are sympatric close relatives which compete for similar resources. Previous non-experimental studies suggest that the smaller sibling vole is a superior competitor, yet more vulnerable to predation than the larger field vole. We studied the effects of coexistence on population densities, reproductive parameters, and survival in these two species by means of experimentation in large, predator-free outdoor enclosures. While populations of both species reached higher densities in the absence of the other, field voles appeared to suffer more from interspecific competition than sibling voles. The proportion of young individuals in the population was higher in the sibling vole than in the field vole at the end of the experiment. The presence of a coexisting species reduced the survival of field voles. Sibling voles, on the other hand, appeared to suffer more from intraspecific competition than interspecific competition. On a population level, the sibling vole seems to be a superior competitor in the absence of predators due to better survival and possibly a higher reproductive capacity. However, predation probably has a profound influence on the interspecific dynamics of these two species indicating that in natural surroundings apparent competition (i.e. competition via shared predators) is stronger than direct competition.  相似文献   

16.
Interspecific competition is usually understood as different species competing directly with each other for limited resources. However, predators can alter such competitive interactions substantially. Predation can promote the coexistence of species in a situation where it would otherwise be impossible, for example if a tradeoff between the competitive abilities and predation resistance of the prey species exists. The field vole Microtus agrestis and the sibling vole M. rossiaemeridionalis are sympatric grassland species, which compete for the same resources. At the population level sibling voles are suggested to be superior competitors to field voles, yet more vulnerable to predation. We tested the effects of predation on the two species in 0.5 ha outdoor enclosures by exposing vole populations to radio-collared freely-hunting least weasels Mustela nivalis nivalis for three weeks. Lethal and non-lethal impacts of predation limited population densities of both species during and after the experimental period, but the effect was more pronounced in sibling voles in which population densities decreased markedly during the treatment period and even after that. Field vole population densities remained stable under weasel predation, while densities increased in controls. Survival in both species was lower in treatment populations compared to controls, but the effect tended to be more pronounced in sibling voles and in females of both species. The average mass of adults in both species declined in the treatment populations. These results suggest that predation by least weasels can limit vole populations locally, even during favourable summer conditions, and have extended negative effects on the dynamics of vole populations. In addition, predation alleviated interspecific competition between the vole species and is, therefore, a potential factor enabling the coexistence of them.  相似文献   

17.
Fey K  Banks PB  Korpimäki E 《Oecologia》2008,157(3):419-428
Ecosystems of three trophic levels may be bottom-up (by food-plant availability) and/or top-down (by predators) limited. Top-down control might be of greater consequence when the predation impact comes from an alien predator. We conducted a replicated two-factor experiment with field voles (Microtus agrestis) during 2004-2005 on small islands of the outer archipelago of the Baltic Sea, south-west Finland, manipulating both predation impact by introduced American mink (Mustela vison) and winter food supply. In autumn 2004, we live-trapped voles on five islands from which mink had been consistently removed, and on four islands where mink were present, and provided half of these islands with 1.8 kg oats per vole. Body mass of female voles increased as a response to supplementary food, whereas both food supplementation and mink removal increased the body mass of male voles in subsequent spring. During winter, there was a positive effect of supplementary food, but in the subsequent summer, possible positive long-term impacts of food supplementation on field voles were not detected. Mink removal appeared not to affect density estimates of field voles during the winter and summer immediately after food addition. Trapping data from 2004 to 2005 and 2007 suggested, however, that in two out of three summers densities of voles were significantly higher in the absence than in the presence of mink. We conclude that vole populations on small islands in the archipelago of the Baltic Sea are mainly bottom-up limited during winter (outside the growing season of food plants), when food availability is low, and limited by mink predation during summer which slows population growth during the reproductive season of voles.  相似文献   

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