基于交叉抚育的雌性根田鼠对雄鼠尿气味的识别

通过交叉抚育建立同巢同胞、同巢非同胞、异巢同胞和异巢非同胞个体组成的室内繁殖种群,在断奶后（80日龄）分别取这些供体的新鲜尿作刺激物,在吕字型观察箱中观察和记录雌性根田鼠对雄鼠气味的行为响应,以研究根田鼠同胞识别的化学通讯机制。结果表明：（1）成年雌性根田鼠对雄性同巢同胞气味的接近潜伏期极显著短于对同巢非同胞气味的接近潜伏期（P〈0.01）,而其对两者的访问时间和嗅舔时间之间的差异并不显著（P〉0.05）;（2）雌鼠对雄性异巢同胞和异巢非同胞气味无明显偏好。其对两者的接近潜伏期、访问时间和嗅舔时间等行为响应均无显著差异（P〉0.05）;（3）雌鼠对雄性同巢非同胞和异巢非同胞的接近潜伏期差异并不明显（P〉0.05）,对两者访问时间和嗅舔时间的差别不大（P〉0.05）;（4）比较雌鼠对异巢同胞和同巢同胞气味的行为响应发现,其对后者的接近潜伏期显著短于前者（P〈0.05）,其对两者访问时间、嗅舔时间之间的差异未达到显著水平（P〉0.05）。这些结果表明,80日龄时,雌性根田鼠具有亲属识别能力,其同胞识别的机制可能为共生熟悉和表型匹配两种模式协同作用。     

濒危植物七子花RAPD条件的优化

以改进SDS法抽提濒危植物七子花嫩叶总DNA ,进行随机扩增多态DNA(RAPD)分析 ,分别测试了镁离子 ,dNTP ,模板DNA含量 ,引物和DNA聚合酶量对反应结果的影响 ,通过各因子的组合研究 ,可知七子花RAPD分析较适宜的扩增条件是 :1 5μLPCR反应体积 ,1×Taq酶配套缓冲液 (1 0mmol/LTris·HClpH 9.0 ,50mmol/LKCl,0 .1 %TritonX_1 0 0 ) ,2 .5mmol/LMgCl2 ,2UTaq酶 (上海华美公司 ) ,1 0ng模板DNA ,2 0pmol引物 (上海Sangon公司 ) ;dATP、dCTP、dGTP、dTTP各 0 .1mmol/L。     

Perspective: the evolution of warning coloration is not paradoxical

Animals that are brightly colored have intrigued scientists since the time of Darwin, because it seems surprising that prey should have evolved to be clearly visible to predators. Often this self-advertisement is explained by the prey being unprofitable in some way, with the conspicuous warning coloration helping to protect the prey because it signals to potential predators that the prey is unprofitable. However, such signals only work in this way once predators have learned to associate the conspicuous color with the unprofitability of the prey. The evolution of warning coloration is still widely considered to be a paradox, because it has traditionally been assumed that the very first brightly colored individuals would be at an immediate selective disadvantage because of their greater conspicuousness to predators that are naive to the meaning of the signal. As a result, it has been difficult to understand how a novel conspicuous color morph could ever avoid extinction for long enough for predators to become educated about the signal. Thus, the traditional view that the evolution of warning coloration is difficult to explain rests entirely on assumptions about the foraging behavior of predators. However, we review recent evidence from a range of studies of predator foraging decisions, which refute these established assumptions. These studies show that: (1) Many predators are so conservative in their food preferences that even very conspicuous novel prey morphs are not necessarily at a selective disadvantage. (2) The survival and spread of novel color morphs can be simulated in field and aviary experiments using real predators (birds) foraging on successive generations of artificial prey populations. This work demonstrates that the foraging preferences of predators can regularly (though not always) result in the increase to fixation of a novel morph appearing in a population of familiar-colored prey. Such fixation events occur even if both novel and familiar prey are fully palatable and despite the novel food being much more conspicuous than the familiar prey. These studies therefore provide strong empirical evidence that conspicuous coloration can evolve readily, and repeatedly, as a result of the conservative foraging decisions of predators.     

东北林蛙的两性异形和抱对个体的形态相关性

2012年4月,在吉林省长白山地区,对正在抱对的30对东北林蛙(Rana dybowskii)成体的体长、头长、头宽、前肢长和后肢长进行测量,使用统计学的方法分析抱对个体形态特征的两性异形及配偶间形态特征的相关性.结果表明,两性的所有局部形态特征均与其体长呈显著正相关,其中,前肢长和后肢长随体长的增长速率在两性间无显著差异,而头长和头宽随体长的增长速率存在显著差异.雌性成体显著大于雄性成体;特定体长下雄性的前肢显著大于雌性,其他局部特征没有显著的两性差异;雌性个体与抱对的雄性个体的后肢长呈显著正相关,其余形态特征两性间无相关性.因此,在东北林蛙的配偶选择中,雌性对雄性形态特征的选择与两性异形的形成无显著的相关性.     

12种杀虫剂对柑橘大实蝇选择行为的影响及击倒作用

柑橘大实蝇是柑橘上的重要害虫。本文分别利用Y型嗅觉仪和饲喂法测定了柑橘大实蝇成虫对12种杀虫剂的选择行为和击倒作用,以期筛选出田间防治柑橘大实蝇的高效农药,并为研发其诱杀剂提供理论依据。结果表明:12种杀虫剂中,吡虫啉、阿维菌素对雌成虫具有极显著的驱避作用;多杀霉素、丁硫克百威、阿维菌素、氟铃脲对雄成虫具有极显著的驱避作用;多杀霉素、毒死蜱、噻嗪酮对雌成虫具有显著的驱避作用;啶虫脒、噻虫嗪、乙酰甲胺磷、高效氯氟氰菊酯和高效氯氰菊酯对柑橘大实蝇雌雄成虫既无驱避作用也无引诱作用。同种药剂对柑橘大实蝇雌雄成虫的击倒时间无显著差异,不同药剂间对柑橘大实蝇成虫的击倒时间有显著差异,其中啶虫脒的击倒时间(KD₅₀<1 min)最短。综合考虑杀虫剂对柑橘大实蝇选择行为的影响及击倒作用,认为啶虫脒更适宜作为柑橘大实蝇诱杀剂中的杀虫剂。     

Relative importance of drought,soil quality,and plant species in determining the strength of plant–herbivore interactions

1. Although studies on plant–herbivore interactions comparing different plant species are common, little is known about the importance of environmental conditions in determining variation in herbivory within single plant species. 2. This study assessed the effects of experimentally manipulated nutrient and water availability on plant palatability, and compared these differences with differences among species. The extent to which these patterns can be explained by leaf toughness and specific leaf area was also investigated. Six plant species from the subfamily Carduoideae and four free‐living leaf chewing invertebrates were used in the study. 3. Herbivore preferences were significantly affected by soil nutrients and water regime and varied among plant as well as herbivore species. Generally, herbivores preferred watered plants and plants from nutrient‐poor soil. The effects of soil nutrients and water regime differed between the plant and herbivore species. The differences between the plant species were greater than those between the environmental treatments. Differences at both levels could be partly explained by leaf toughness and specific leaf area. Leaf toughness, in particular, turned to be an important predictor indicating that herbivores preferred species with softer leaves, and species from wetter conditions with reduced leaf toughness. 4. The environmental conditions in which plants are growing have significant effects on plant palatability. Between‐species comparisons thus need to pay attention to this variation. Future studies may consider how the effects of current conditions interact with conditions of plant origin to predict possible effects of changes in environmental conditions on the intensity of plant–herbivore interactions.     

Resource selection by Indiana bats during the maternity season

Little information exists on resource selection by foraging Indiana bats (Myotis sodalis) during the maternity season. Existing studies are based on modest sample sizes because of the rarity of this endangered species and the difficulty of radio-tracking bats. Our objectives were to determine resource selection by foraging Indiana bats during the maternity season and to compare resource use between pregnant and lactating individuals. We used an information theoretic approach with discrete choice modeling based on telemetry data to evaluate our hypotheses that land cover, percent canopy cover, distance to water, and prescribed fire affected the relative probability a point was used by a foraging Indiana bat. We fit models for individual bats and a population-level model based on all individuals with a random factor to account for differences in sample size among individuals. We radio-tracked 29 individuals and found variation in resource selection among individuals. However, among individuals with the same supported covariates, the magnitude and direction of the covariates were similar. Eighteen bats selected areas with greater canopy closure and 5 of 6 bats that had areas burned by low-intensity prescribed fire in their home range selected burned areas. Resource selection was related to land cover for 13 individuals; they selected forest and shrubland over agricultural land, which composed >50% of the landscape within 10 km. We found no support for our hypothesis that resource selection was related to individual reproductive condition or Julian date in our population-level model indicating habitat selection was not determined by reproductive status or date within the maternity season. Land use or forest management that greatly reduces canopy cover may have a negative impact on Indiana bat use. Maintaining forest cover in agricultural landscapes is likely critical to persistence of maternity colonies in these landscapes. Sites managed with low severity prescribed fire may be selected by some individuals because of reduced understory vegetation. © 2013 The Wildlife Society.     

Does the time spent near a male predict female mate choice in a Malawian cichlid?

Gravid female Malawian Pseudotropheus cichlids spent significantly more time with males that they subsequently chose as mates, indicating that time spent near a male is a valid and accurate method of measuring female preference. Furthermore, females preferred to mate with males that had longer pelvic fins and a larger number of eggspots on their anal fins. In some instances, females chose to mate with both of the males with which they were presented, possibly because they were unable to discriminate between them.