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301.
M. L. Thomas C. M. Payne-Makrisâ A. V. Suarez N. D. Tsutsui D. A. Holway 《Insectes Sociaux》2007,54(3):225-233
Complex recognition systems underlie the social organization of many organisms. In social insects the acceptance of other
individuals as nestmates can involve a variety of different cues, but the relative importance of these cues can change in
relation to the fitness costs of accepting or rejecting other individuals. In this study we investigate the mechanisms that
underlie recognition behaviour in Argentine ants (Linepithema humile). Introduced populations of Argentine ants are characterized by a social structure known as unicoloniality where intraspecific
aggression is absent over large distances resulting in the formation of expansive supercolonies. Recent research has identified
sites where multiple, mutually aggressive supercolonies co-occur allowing an examination of Argentine ant behaviour at territorial
boundaries. We found that workers from different supercolonies always interact aggressively with one another, but that neighbours
from different colonies (i.e., workers from nests located in the immediate vicinity of territory borders) consistently exhibited
higher levels of aggression compared to those displayed by non-neighbours from different colonies (i.e., workers from nests
located far enough away from a territory border so that interactions are unlikely). This difference in the level of aggression
displayed between neighbours and between non-neighbours from different supercolonies cannot be explained by differences in
relatedness or genetic similarity. Instead our findings suggest that direct contact between mutually antagonistic colonies
is sufficient to elevate aggression. A laboratory experiment in which we manipulated the extent to which colonies with no
prior history of contact could interact with one another, revealed that aggression increased after colonies were permitted
to interact, but dropped after connections between colonies were severed. Moreover, the mere presence of an aggressive supercolony
was sufficient to elicit elevated aggression. Overall these patterns are opposite to the “dear enemy” phenomenon and could
be the result of the intense territorial aggression exhibited by established supercolonies of this species.
Received 8 January 2007; revised 27 March 2007; accepted 28 March 2007. 相似文献
302.
Tetsuo Kuwamura 《Ecological Research》1992,7(1):43-53
Males of the herbivorous cichlid fishPseudosimochromis curvifrons established mating territories 3–10 m in diameter, which included both spawning and feeding sites. Territorial males attacked
conspecific males and also other species. Only conspecific males were chased out of the territories. Territorial males attacked
other species at the spawning sites while courting or waiting for females and at other sites in their territories while patrolling
and foraging. Attacks against herbivorous species were more frequent than against non-herbivores since herbivores were much
more abundant. Territories of four abundant herbivorous cichlids largely overlapped the territories ofP. curvifrons males. Symbiotic relationships were not detected between the species. Instead, they were aggressive towards each other but
coexisted by segregating feeding sites in the overlapping areas. The aggressive coexistence ofP. curvifrons males with other herbivores may have resulted from the energetic costs of defending their relatively large territories against
all food competitors. Interspecific food-resource partitioning may also have facilitated the coexistence. 相似文献
303.
Grooming among adult and older juvenile females in a wild group of blue monkeys (Cercopithecus mitis stuhlmanni) is analyzed and related to agonistic behavior. Both grooming and agonistic behavior were less frequent than would be expected
in baboon and macaque groups. Fair shares of grooming were given and taken, both within and between interactions, in amost
dyads, and all females were seen to groom with at least half the others. The reciprovity of grooming was its most outstanding
feature. There was no evidence that grooming was preferentially directed at kin. Frequent grooming partnerships fell into
two clusters, one of which ranked higher than the other. We suggest that grooming throughout the group helps to establish
a coherent team of females which effectively, defends its territory in daily encounters at the boundaries with neighboring
groups. 相似文献
304.
Robert Zabawa 《Human ecology: an interdisciplinary journal》1991,19(1):61-81
Black-American culture has been tied to the land and agriculture for over 300 years. However, Blacks have had limited access to land ownership due to a historic relationship with a dominant White society based on discrimination. This major resource constraint prevented the full participation of the Black farmer in traditional commercial agriculture. Research conducted in the Black Belt Region of Alabama is used to examine the importance of land, particularly the multigenerational ownership of land, on current farm participation and landholdings. Strategies employed by farmers to pass this scarce resource to succeeding generations are also examined. 相似文献
305.
Covert extraterritorial behavior of female hooded warblers 总被引:3,自引:1,他引:2
Extraterritorial forays are one specialized tactic that femalesuse to obtain extrapair copulations (EPCs). By radio-trackingfemale hooded warblers (Wilionia citrina) during the breedingseason, we found that females made covert forays onto neighboringterritories. Almost 80% of females made extraterritorial foraysduring their fertile stages, but none visited territories duringthe nonfertile (incubation) stage, which is consistent withthe extraterritorial foray hypothesis. Females that left theirterritories visited from one to four neighboring territories,and they intruded at a rate of 0.6 territories/h. The propensityof females to foray from their territory did not correlate withbody size or age of the social mate. One female that left herterritory obtained an extrapair fertilization. Females may useforays to assess male quality as well as participate in extrapaircopulations. An alternative hypothesis for extra-territorialforays is that females may foray onto neighboring territoriesto obtain food during the energetically stressful period ofegg production. The extraterritorial foray hypothesis and foraginghypothesis may not be mutually exclusive. Females may obtainbenefits of foraging while at the same time assessing malesfor EPCs. Extraterritorial behavior of female birds may be morecommon than previously believed and in many cases may only beruled out through radio-tracking 相似文献
306.
T. Yamaguchi 《Insectes Sociaux》1995,42(1):89-101
Summary Intraspecific interference competition in the harvester ant,Messor aciculatus, was studied. Colonies of this species were found not to have territories. Some nests were located very close to each other, and the foraging areas of the neighbors usually overlapped. Even though the frequency with which alien and resident ants met was very high in the vicinity of the nest entrances, aggressive interactions between them rarely occurred. However, when hostile workers encountered each other, they exhibited a kind of ritualized combat and the winner ejected, but did not injure the loser. If any aliens entered the nest, some of them were pulled out, mainly by the residents.Aliens roaming near a neighbor's nest entrance ferociously attacked the residents carrying seeds in their mandibles and robbed them. On other occasions, aliens entered the nest and stole the collected seed. Although seed robbing and stealing occurred among neighboring colonies, there were remarkable differences in the frequency of their occurrence. The results of field observations and experiments suggest the existence of a dominance order among the neighbors. In one instance, extermination of an inferior colony by its neighbor was observed. The raider colony transferred the stored seeds from the nest of the inferior colony to its own and deposited the larvae and workers some distance away from the nest.The influence of ritualized combat and food robbing on colony activities, and the ecological significance of this interference behavior in terms of spatial distribution and temporal persistence of the nest sites, is discussed. 相似文献
307.
Homologous Chromosome Pairing in Drosophila melanogaster Proceeds through Multiple Independent Initiations 总被引:6,自引:0,他引:6 下载免费PDF全文
Jennifer C. Fung Wallace F. Marshall Abby Dernburg David A. Agard John W. Sedat 《The Journal of cell biology》1998,141(1):5-20
The dynamics by which homologous chromosomes pair is currently unknown. Here, we use fluorescence in situ hybridization in combination with three-dimensional optical microscopy to show that homologous pairing of the somatic chromosome arm 2L in Drosophila occurs by independent initiation of pairing at discrete loci rather than by a processive zippering of sites along the length of chromosome. By evaluating the pairing frequencies of 11 loci on chromosome arm 2L over several timepoints during Drosophila embryonic development, we show that all 11 loci are paired very early in Drosophila development, within 13 h after egg deposition. To elucidate whether such pairing occurs by directed or undirected motion, we analyzed the pairing kinetics of histone loci during nuclear cycle 14. By measuring changes of nuclear length and correlating these changes with progression of time during cycle 14, we were able to express the pairing frequency and distance between homologous loci as a function of time. Comparing the experimentally determined dynamics of pairing to simulations based on previously proposed models of pairing motion, we show that the observed pairing kinetics are most consistent with a constrained random walk model and not consistent with a directed motion model. Thus, we conclude that simple random contacts through diffusion could suffice to allow pairing of homologous sites. 相似文献
308.
Kokko Hanna; Lindstrom Jan; Alatalo Rauno V.; Rintamaki Pekka T. 《Behavioral ecology》1998,9(4):376-383
The importance of a central territory position as a determinantof male mating success in lekking species has been debated.The process by which a male can obtain a central territory hasbeen especially lacking a quantitative analysis. We presenta stochastic queuing model describing territory succession towardthe lek center and apply it to a 8-year sequence of territorycentrality measures on a black grouse Tetrao tetrix lek. Thelek shows a value of intermediate queue discipline, which deviatessignificantly both from strict orderly queuing and from randomranking of males. Thus, high-ranking males are partly able tomaintain their superior position over years, but queue-jumpingis not excluded; especially because highly succesful males donot attempt to change their territory position toward the lekcenter. As a result of stochastic queuing, a central territoryindicates an older than average male, as well as a male witha history of high fighting rates. These results are consistentwith the hypotheses that territory position is an honest signalof male quality and that the long-term fighting effort and survivalrequired to acquire a central territory may increase the reliabilityof the signal over that of short-term display effort. The impartialqueue discipline, however, also leaves room for other male characteristicsto play a role in determining individual mating success. 相似文献
309.
Reproductive consequences of bilateral asymmetry for individual male red-winged blackbirds 总被引:1,自引:0,他引:1
We used morphological and breeding data from a 2-year fieldstudy of red-winged blackbirds (Agelaius phoeniceus) to testthe hypothesis that males characterized by low levels of bilateralasymmetry (i.e., high developmental competence) realize a reproductiveadvantage. Specifically, we evaluated each of several distinctcomponents of male reproductive success relative to asymmetrymeasures made on five bilaterally paired characters. Resultsof a male removal experiment generally failed to support theprediction that symmetry would be associated with success incompetition for access to breeding territories: establishedterritory owners and nonterritorial replacement males were effectivelyindistinguishable in this regard. Similarly, there was no indicationthat symmetrical males were more likely to establish territoriesin high-quality marsh habitat than in marginal upland fieldhabitat. Finally, monitoring of breeding activity in high-qualityhabitat revealed that male symmetry was generally unrelatedto recruitment of social mates (i.e., harem size), the productivityof those mates (average female reproductive success), withinpairpaternity (assessed using DNA-based analysis of parentage),or extrapair mating success. Collectively these results indicatethat symmetry is not an important determinant of reproductivesuccess among individual male red-winged blackbirds. This observation,in combination with the results of several other recent investigations,suggests that the fitness consequences of subtle departuresfrom perfect symmetry may be less significant and/or less ubiquitousthan initially suggested. 相似文献
310.
灰喜鹊的行为生态学研究 Ⅰ.生殖行为 总被引:1,自引:0,他引:1
在从南到北的地理分布上,灰喜鹊的繁殖期相应有所推迟.在它们的繁殖区域,人类的影响越大,其巢也建得越高、越隐蔽.这种很强的适应性使得它们在城区和近郊区能够更好地生存和繁殖.北京地区的灰喜鹊在4月中、下旬开始建巢,5月底是产卵高峰期.在孵卵期它们不断地翻动卵,以使其受热均匀.灰喜鹊对卵的数量比对卵的颜色和大小更敏感.孵卵期约15—17天,幼鸟18—20天出巢.在北京大学校园内的灰喜鹊的繁殖成功率约为69.05%.建立了灰喜鹊的发育行为谱.在繁殖期,灰喜鹊的巢彼此靠得较近,形成一个集体生殖领域,共同进行集体防御. 相似文献