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排序方式: 共有116条查询结果,搜索用时 796 毫秒
31.
László Zsolt Garamszegi Balázs Rosivall Gergely Hegyi Eszter Szöllösi János Török Marcel Eens 《Behavioral ecology and sociobiology》2006,60(5):663-671
In intrasexual conflicts, contestants can rely on relative or absolute size of status badges to mediate aggressive behavior. Most studies focus on the response of focal animals to variation in status badges of their competitors; few have simultaneously considered the traits of both participants under experimental conditions. By simulating territorial intrusions, we tested the importance of two sexual traits [forehead patch size (FPS) and wing patch size (WPS)] in territorial behavior of males in a Hungarian population of the collared flycatcher, Ficedula albicollis. We presented a stimulus male to an unpaired resident male to examine whether the characteristics of the territory owner or those of the challenger were associated with the latency of the first attack of the owner, which is a good predictor of the territorial behavior in general. WPS of the stimulus male was a significant determinant of the latency of the first attack, as males with a larger WPS elicited quicker attacks from the residents than males with a small WPS. From the residents’ perspective, age appeared to influence their territorial behavior, as yearlings had shorter attack latencies than older males. Additionally, latency could be considered an individual-specific attribute because it varied consistently among males, even when the WPS of the stimulus male was controlled, and it was associated with pairing success. Contrary to findings in a Swedish population, FPS seemed to be unimportant in male–male competition in our population, which suggests population differences in the role of the two plumage traits. Our results indicate that in a territorial conflict, the characteristics of both participants are important. 相似文献
32.
Summary. This study reports on the impact of insecticidal resistance on the diel periodicity of the calling behaviour and pheromone
production of different-aged virgin females of the obliquebanded leafroller (OBL), Choristoneura rosaceana. While both resistant (R) and susceptible (S) females initiated calling on the first night following emergence, the periodicity
of the calling behaviour, as determined by the mean onset time of calling (MOTC) and the mean time spent calling (MTSC) over
the first six nights of calling, differed between the two strains. R females started calling significantly later in the night.
However, as the MOTC of R females advanced with age but did not do so in S individuals, the difference between strains was
more pronounced in younger than older females. Furthermore, R females spent less time calling than S individuals. However,
the MTSC increased as a function of age in both R and S females, so the difference between strains remained fairly constant
for each night of calling. The major component of OBL sex pheromone, the Z11-14: Ac, determined at peak calling activity,
significantly declined with female age. Overall, pheromone production was lower in R females than in S females, with the difference
being more pronounced in younger than in older individuals. Thus, resistant females may have a lower mating success. The mating
success of both R and S strain males did not vary with the number of previous matings acquired. With regard to males, although
there was a significant decline in spermatophore size with successive matings, there was no significant difference between
strains. However, R males are smaller and may be disadvantaged through female choice and/or may respond differently to pheromone
source compared with S individuals. If the reproductive success of both sexes is affected, this may have a profound influence
on the dynamics of insecticidal resistance in the presence or absence of selection in OBL populations.
Received 4 July 2001; accepted 19 October 2001. 相似文献
33.
Kevin J. Delaney J. Andrew Roberts George W. Uetz 《Behavioral ecology and sociobiology》2007,62(1):67-75
Male signaling behaviors are often studied in a single context but may serve multiple functions (e.g., in male–male competition
and female mate choice). We examined the issue of dual function male signals in a wolf spider species Schizocosa ocreata (Hentz) that displays the same species-specific signaling behaviors in both male–male and male–female contexts. These signaling
behaviors have been described as either aggression or courtship according to the context observed. We tested the possibility
of dual functions by comparing the relationship between behaviors and outcome of male–male contests (winner/loser) and male–female
mating encounters (mating success). Frequency, rate, and mean duration of signaling behaviors did not vary with outcome of
male–male contests, which appears instead to be based upon relative size and body mass. Winners of contests had significantly
greater body mass than losers, and greater mass relative to opponents was significantly associated with probability of winning.
Overall, signaling rates were much higher in male–female interactions than in male–male contests and were higher for males
that successfully mated than for those that did not mate. Mean duration of some male displays was also greater for males that
successfully mated. However, male size was not associated with probability of mating. Taken together, results suggest an intersexual
selection context for the current function of male signals in these wolf spiders and that increased display vigor is associated
with male mating success. 相似文献
34.
本研究以模式动物斑马鱼(Danio rerio)为受试生物,采用半静态水体暴露的方式研究了不同浓度壬基酚聚氧乙烯醚(NPEO)对斑马鱼雄性成鱼下丘脑-垂体-性腺轴(HPG轴)的影响.结果显示,考察浓度范围内的NPEO暴露可以显著上调斑马鱼脑中GnRH2、GnRHR1、GnRHR2、GnRHR4、FSHβ和LHβ基因,以及性腺中LHR基因的相对表达量.GnRHR和LHR基因表达量对较低浓度NPEO暴露较为敏感,其中GnRHR4和LHR基因表达量在低至0.001mg/L的NPEO暴露下即出现显著上调.0.1和10mg/L NPEO暴露可以显著抑制斑马鱼精巢中CYP17基因的表达量,而10mg/L NPEO暴露则可以显著诱导CYP19a基因的表达量.GnRH相关调控基因表达量的上调,表明NPEO暴露可以诱导下丘脑分泌GnRH,进而刺激垂体分泌GtH.NPEO暴露诱导CYP19a基因的表达,促进了内源雌激素的合成.同时,NPEO通过抑制CYP17表达,可能抑制睾酮(T)的合成,干扰斑马鱼精巢中原有的性激素平衡.斑马鱼精巢内雌激素水平升高负反馈给垂体,刺激垂体分泌促性腺激素.由此表明,考察浓度范围内(0.001~10mg/L)的NPEO的暴露可以影响雄性斑马鱼成鱼HPG轴的反馈调节. 相似文献
35.
Pentoxifylline (PTX) is a clinically used drug mainly for peripheral circulation improvement. This drug also possesses potent anti-inflammatory effects and was found to inhibit acute lung injury induced by chemical agents in animal models. Since it is also a potential apoptosis enhancer, this study was designed to examine the influence of PTX on silica-induced lung inflammation and pulmonary leucocyte apoptosis. Male Wistar rats were intratracheally instilled with either silica dust suspension or saline and intraperitoneally injected with saline or PTX. These treatments continued for six weeks and all rats were then sacrificed to obtain bronchoalveolar lavage cells and lavage fluid. Data demonstrated that PTX attenuated silica-induced lung injury in the rat model and this attenuation may possibly be attributed to its role in the enhancement of pulmonary apoptosis. As a known clinically safe drug, PTX may thus have potential use in the treatment of human silicosis. 相似文献
36.
S. V. Titov 《Russian Journal of Ecology》2003,34(4):255-260
Natural dispersal of young animals was studied in the colonies of Spermophilus major and S. suslicus ground squirrels in the Volga region. On the basis of data obtained, this process was modeled taking into account the spatial–ethological structure of the colonies. In both species, male dispersal was more active, whereas the degree of natal philopatry was higher in females. The results of the study do not confirm the aggression concept of juvenile dispersal and indicate that its causes are related to hereditary behavioral tendencies. These results are compared with data on juvenile dispersal in other species of the genus Spermophilus. 相似文献
37.
38.
运用单细胞凝胶电泳技术,研究了太原市大气细颗粒物(PM2.5)对分离的大鼠肺泡巨噬细胞 DNA 的损伤作用.结果表明,在 PM2.5浓度分别为 0,75,150,300,450μg/mL 的染毒条件下,染毒 1h 后,大鼠肺泡巨噬细胞 DNA 拖尾长度分别为 2.82,6.76,10.25,14.47,23.87μm;染毒 4h后,DNA 拖尾长度分别为 2.80,18.15,32.90,43.22,55.51μm;染毒 10h 后,DNA 拖尾长度分别为 2.49,26.57,39.73,52.10,70.09μm.由此可见,PM2.5可引起大鼠肺泡巨噬细胞 DNA 的损伤,且随着 PM2.5浓度的增加及染毒时间的延长而加剧,呈明确的剂量-效应关系和时间-效应关系. 相似文献
39.
40.
T. J. Bergman J. C. Beehner D. L. Cheney R. M. Seyfarth P. L. Whitten 《Behavioral ecology and sociobiology》2006,59(4):480-489
To date, research on testosterone and behavior has focused on individuals, even when studying social behaviors that necessarily
involve multiple participants. Here, we explore male responses to other males of different dominance ranks and testosterone
levels in a population of wild baboons. In chacma baboons (Papio hamadryas ursinus) of the Okavango Delta, a male’s testosterone is related to his rank trajectory and, therefore, the threat he poses to other
males. To examine the effects of testosterone and rank on male–male interactions, we used playback experiments to measure
how a target male responded to the simulated approach of another male, scoring responses by whether or not the subject moved
away from the speaker in the first minute. High testosterone subjects did not move away from the speaker more often than low
testosterone subjects, but high testosterone callers elicited a move more often than low testosterone callers. When the combined
testosterone of the subject and caller was high, moves were most common. The rank relationship between subject and caller
did not predict moves, but the effect of combined testosterone on moving was most pronounced in adjacently ranked males. Adjacently
ranked, high testosterone males are the most likely to be competing for each others’ rank, and our experiments on these dyads
elicited the most moves. Both behavioral and experimental observations indicate that testosterone may be more important than
the rank relationship in predicting the outcome of male–male interactions. Furthermore, combined information on the testosterone
of both males was the best predictor of results, highlighting the utility of dyadic analyses when relating testosterone to
behavior. 相似文献