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1.
The spectacular social courtship displays of lekking birds are thought to evolve via sexual selection, but this view does not easily explain the participation of many males that apparently fail to mate. One of several proposed solutions to this 'lek skew paradox' is that kin selection favours low-ranking males joining leks to increase the fitness of closely related breeders. We investigated the potential for kin selection to operate in leks of the greater sage grouse, Centrocercus urophasianus, by estimating relatedness between lekking males using microsatellite DNA markers. We also calibrated these estimates using data from known families. Mean relatedness within leks was statistically indistinguishable from zero. We also found no evidence for local clustering of kin during lek display, although males tended to range closer to kin when off the lek. These results make kin selection an unlikely solution to the lek skew paradox in sage grouse. Together with other recent studies, they also raise the question of why kin selection apparently promotes social courtship in some lekking species, but not in others. 相似文献
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Boyko AR 《The American naturalist》2004,163(1):154-165
Leks often attract predators as well as mates, yet most evolutionary models have assumed that sexual selection, not predation, drives lekking behavior. We explored the influence of predation on lek dynamics using a stochastic dynamic game model based on the lek-breeding greater sage grouse (Centrocercus urophasianus) and its principal avian predator, the golden eagle (Aquila chrysaetos). The model predicts time-dependent male lek attendance as a function of factors affecting both mating success (female arrival rate, male numbers, and social status) and predation risk (eagle arrival rate and group size). Dominant males are predicted to arrive sooner and leave later than subordinates, especially if mating skew is high, predation risk is low, or the relationship between lek size and female arrival rate is weak. Both high mean levels of predation risk and small lek size should reduce lek attendance, but the relative tendency of predators to attack large versus small leks has little influence on predicted lekking behavior. Field observations confirmed the predicted effects of female arrival rate, lek size, male dominance, and weather-dependent predator arrival rates on lek departure times. Predicted effects of female arrival rates and male dominance on seasonal lek attendance were also supported. Our model provides an empirically supported adaptive explanation for short-term lek dynamics. It also suggests alternative interpretations for phenomena previously invoked to support the hotshot and skew models of lek formation. 相似文献
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Alatalo Rauno V.; Hoglund Jacob; Lundberg Arne; Sutherland William J. 《Behavioral ecology》1992,3(1):53-59
Leks, communal display grounds in which males display and femalesonly attend to mate, represent one of the most remarkable outcomesof sexual selection. There have been no detailed studies thatcompare the behavior of males and females between leks of differentsizes to test if there is any benefit for male clumping andto test the many hypotheses suggested to explain lekking. Inthe black grouse, Tetrao tetrix, larger leks have many morefemale visits and copulations, leading to a higher average malemating success. Females visiting larger leks are also more likelyto mate, indicating that female preferences of males are importantfor the evolution of leks. Yearling males seldom copulate, buttheir presence on the lek increases the mating success of adultmales, suggesting that lek size per se and not only male qualityaffects female preferences for larger leks. The distributionof males over lek sizes agrees with a game theory model of idealfree distribution with unequal competitors, in which less competitivemales go to smaller leks. 相似文献
4.
In lekking species, males cluster on specific areas for display (the leks) and females generally prefer to copulate with males on large aggregations. The maintenance of leks in which only a few males reproduce might be explained if subordinate males gain indirect fitness benefits. By joining a lek on which relatives are displaying, subordinates might attract more females to the lek thereby increasing the mating opportunities of their kin. In black grouse, a genetic structure among leks has previously been found suggesting that relatives could display together. Using 11 microsatellite loci, we extended this result by testing for the presence of kin structures in nine black grouse leks (101 males). The genetic differentiation among flocks was higher in males than in females, suggesting female-biased dispersal and male philopatry. Because of this genetic structure, males were more related within than among leks. However, the mean relatedness within each lek hardly differed from zero. The lekking males were not more related than random assortments of males from the winter flocks and there were no kin clusters within leks. Thus, black grouse males do not choose to display with and close to relatives. Male philopatry alone was not sufficient to induce elevated levels of relatedness on the leks either because of male partial dispersal or a rapid turnover of the successful males. The indirect fitness benefits associated with males' settlement decision are probably limited compared to the direct benefits of joining large aggregations such as increased current and future mating opportunities. 相似文献
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Erik J. Blomberg James S. Sedinger Daniel V. Nonne Michael T. Atamian 《Journal of avian biology》2013,44(2):149-158
Tradeoffs among demographic traits are a central component of life history theory. We investigated tradeoffs between reproductive effort and survival in female greater sage‐grouse breeding in the American Great Basin, while also considering reproductive heterogeneity by examining covariance among current and future reproductive success. We analyzed survival and reproductive histories from 328 individual female greater sage‐grouse captured between 2003 and 2011, and examined the effect of reproductive effort on survival and future reproduction. Monthly survival of females was variable within years, and this within‐year variation was associated with distinct biological seasons. Monthly survival was greatest during the winter (November–March; ΦW= 0.99 ± 0.001 SE), and summer (June–July; ΦS= 0.98 ± 0.01 SE), and lower during nesting (April–May; ΦN= 0.93 ± 0.02 SE) and fall (August–October; ΦF= 0.92 ± 0.02 SE). Successful reproduction was associated with reduced monthly survival during summer and fall, and this effect was greatest during fall. Females that successfully fledged chicks had lower annual survival (0.47 ± 0.05 SE) than females who were not successful (0.64 ± 0.04 SE). Annual survival did not vary across years, consistent with a slow‐paced life history strategy in greater sage‐grouse. In contrast, reproductive success varied widely, and was positively correlated with annual rainfall. We found evidence for heterogeneity among females with respect to reproductive success; compared with unsuccessful females, females that raised a brood successfully in year t were more than twice as likely to be successful in year t+ 1. Female greater sage‐grouse incur costs to survival associated with reproduction, however, variation in quality among females may override costs to subsequent reproductive output. 相似文献
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Jennifer Williams 《Oecologia》1985,65(2):269-272
Summary Serial correlations were performed on grouse bag data spanning periods of 40 to 100 years and taken from throughout the British Isles, to test for the presence of cyclical fluctuations. Six of the fourteen series analysed showed clear evidence of a 6-year cycle in bag numbers. Four of the remaining series produced correlograms suggestive of cycles of other lengths. Only four of the series analysed showed no evidence of cyclicity. 相似文献
8.
Ragne Oja Eliisa Pass Egle Soe Karli Ligi Peeter Anijalg Leidi Laurimaa Urmas Saarma Asko Lõhmus Harri Valdmann 《European Journal of Wildlife Research》2018,64(1):6
Protecting animal aggregation sites is intuitively an efficient conservation approach, particularly for threatened species in fragmented landscapes. However, the appropriate scale of protection depends on accompanying threats, such as predator attraction to the same aggregation sites, to which the target species may need to respond by moving to alternative habitat patches. We performed experiments using artificial ground nests around protected capercaillie leks in commercially managed forest landscape in Estonia. We considered two scales: the landscape up to 3 km from the lek centre, and among 10–30-ha forest compartments, which differed in predator abundance. We found that nest predation significantly declined with distance from the lek. Nests were depredated by multiple mammalian and avian predator species and total predator abundance explained most of the between-forest variation in predation rate. Our results indicate that, in this hemiboreal area, (i) ground nest predation is largely determined by landscape-scale distribution of predators and (ii) predators can aggregate at capercaillie leks. The implication is that lek-centred habitat protection used for the capercaillie and other grouse may be ineffective unless the peripheral habitat quality and predator abundance are specifically addressed. More generally, predation pressure can be a serious problem in small set-asides within hostile landscapes for threatened ground-nesting birds. 相似文献
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Salvia officinalis L. and the closely related Salvia fruticosa Mill. (Lamiaceae) are amongst the economically most important medicinal and aromatic plants. Both species are rich in essential oil, which can vary significantly and is partly responsible for their bioactivity and sensorial properties. Therefore we studied its variability within Albania, one of the main exporters of both species. In S. officinalis a clear geographical gradient could be observed from North to South, based mainly on a trade-off between the thujones (α- and β-thujone) and camphor. The differences between the provinces were so pronounced that the essential oil profile could be used to identify the origin of unknown samples from within Albania to a high degree of certainty. The variability within S. fruticosa was not as pronounced due to its restricted distribution to coastal regions in the South–West only. No hybrids between the two species could be found in the overlapping distribution areas. 相似文献
11.
1. Thirgood & Redpath (2008) propose ways in which red grouse : hen harrier conflicts could be resolved. It has also been suggested that grouse management could accept lower bag sizes (number of birds shot) thus reducing the need for intensive management of predators and habitats. This would allow hen harriers to co-exist more easily on grouse moors.
2. We compare the bags, costs and incomes from these less intensive forms of grouse shooting with the more intensive driven shooting.
3. Allowing high density grouse moors to decline to low density ones will result in greater loss of income than the corresponding saving of costs. This can result in moor owners abandoning grouse management and thus gamekeepers losing their employment.
4. Losing gamekeepers from the uplands would jeopardize the protection of heather moorland and Special Protection Areas for birds, large areas of which are keepered and which currently support high numbers of breeding waders.
5. Synthesis and applications . We agree with the study by Thirgood & Redpath that consideration of social and economic factors will be needed to resolve conflict but a reduction in management effort from driven to walked-up shooting is not the answer. A more satisfactory approach to the harrier : grouse conflict could be to try to reduce harrier predation by means of diversionary feeding and to address the problem of the rapid build-up in harrier numbers by exploring the use of a ceiling on harrier densities. 相似文献
2. We compare the bags, costs and incomes from these less intensive forms of grouse shooting with the more intensive driven shooting.
3. Allowing high density grouse moors to decline to low density ones will result in greater loss of income than the corresponding saving of costs. This can result in moor owners abandoning grouse management and thus gamekeepers losing their employment.
4. Losing gamekeepers from the uplands would jeopardize the protection of heather moorland and Special Protection Areas for birds, large areas of which are keepered and which currently support high numbers of breeding waders.
5. Synthesis and applications . We agree with the study by Thirgood & Redpath that consideration of social and economic factors will be needed to resolve conflict but a reduction in management effort from driven to walked-up shooting is not the answer. A more satisfactory approach to the harrier : grouse conflict could be to try to reduce harrier predation by means of diversionary feeding and to address the problem of the rapid build-up in harrier numbers by exploring the use of a ceiling on harrier densities. 相似文献
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Long-range translational coupling in single-stranded RNA bacteriophages: an evolutionary analysis. 总被引:4,自引:0,他引:4
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In coliphage MS2 RNA a long-distance interaction (LDI) between an internal segment of the upstream coat gene and the start region of the replicase gene prevents initiation of replicase synthesis in the absence of coat gene translation. Elongating ribosomes break up the repressor LDI and thus activate the hidden initiation site. Expression studies on partial MS2 cDNA clones identified base pairing between 1427-1433 and 1738-1744, the so-called Min Jou (MJ) interaction, as the molecular basis for the long-range coupling mechanism. Here, we examine the biological significance of this interaction for the control of replicase gene translation. The LDI was disrupted by mutations in the 3'-side and the evolutionary adaptation was monitored upon phage passaging. Two categories of pseudorevertants emerged. The first type had restored the MJ interaction but not necessarily the native sequence. The pseudorevertants of the second type acquired a compensatory substitution some 80 nt downstream of the MJ interaction that stabilizes an adjacent LDI. In one examined case we confirmed that the second site mutations had restored coat-replicase translational coupling. Our results show the importance of translational control for fitness of the phage. They also reveal that the structure that buries the replicase start extends to structure elements bordering the MJ interaction. 相似文献
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Competition for females on leks when male competitive abilities differ: empirical test of a model 总被引:1,自引:0,他引:1
Leks are mating arenas visited by females seeking copulationsand can be thought of as patches differing in female encounterrate. Recently, the ideal free distribution model of unequalcompetitors with interference has been applied to explain maledistributions between leks. This model predicts that the malesof highest competitive ability should be present on the lekswith the highest female encounter rates and should be most successful.I tested the predictions from the model with empirical datafrom the ruff, Philomachus pugnax. Contrary to the predictionsfrom the model, low-ranking males preferentially visited theleks with highest female encounter rates, where the degree ofmale aggression was greatest Furthermore, there was no generalrelationship between female encounter rate and male success,and the empirical data again refute the predictions from themodel. The results illustrate the problem of using male per-capitasuccess when predicting individual behavior. Several more generalproblems with applying the ideal free distribution of unequalcompetitors model to competition for mates are also discussed. 相似文献
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Dispersal and habitat connectivity in complex heterogeneous landscapes: an analysis with a GIS-based random walk model 总被引:7,自引:0,他引:7
A grid-based random walk model has been developed to simulate animal dispersal, taking landscape heterogeneity and linear barriers such as roads and rivers into account The model can be used to estimate connectivity and has been parametenzed for the badger in the central Netherlands The importance of key parameters was evaluated by means of sensitivity analysis Results agree with field observations, and give interesting insight into the isolation of populations and potential populations The model can be applied to obtain knowledge about dispersal processes in complex landscapes 相似文献
16.
Comparison of microarray and sage techniques in gene expression analysis of human glioblastoma 总被引:1,自引:0,他引:1
Kavsan VM Dmitrenko VV Shostak KO Bukreieva TV Vitak NY Simirenko OE Malisheva TA Shamayev MI Rozumenko VD Zozulya YA 《T?Sitologii?a i genetika》2007,41(1):36-55
To enhance glioblastoma (GB) marker discovery we compared gene expression in GB with human normal brain (NB) by accessing SAGE Genie web site and compared obtained results with published data. Nine GB and five NB SAGE-libraries were analyzed using the Digital Gene Expression Displayer (DGED), the results of DGED were tested by Northern blot analysis and RT-PCR of arbitrary selected genes. Review of available data from the articles on gene expression profiling by microarray-based hybridization showed as few as 35 overlapped genes with increased expression in GB. Some of them were identified in four articles, but most genes in three or even in two investigations. There was found also some differences between SAGE results of GB analysis. Digital Gene Expression Displayer approach revealed 676 genes differentially expressed in GB vs. NB with cut-off ratio: twofold change and P < or = 0.05. Differential expression of selectedgenes obtained by DGED was confirmed by Northern analysis and RT-PCR. Altogether, only 105 of 955 genes presented in published investigations were among the genes obtained by DGED. Comparison of the results obtained by microarrays and SAGE is very complicated because authors present only the most prominent differentially expressed genes. However, even available data give quite poor overlapping of genes revealed by microarrays. Some differences between results obtained by SAGE in different investigations can be explained by high dependence on the statistical methods used. As for now, the best solution to search for molecular tumor markers is to compare all available results and to select only those genes, which significant expression in tumor combined with very low expression in normal tissues was reproduced in several articles. 105 differentially expressed genes, common to both methods, can be included in the list of candidates for the molecular typing of GBs. Some genes, encoded cell surface or extra-cellular proteins may be useful for targeting gliomas with antibody-based therapy. 相似文献
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In conservation and management of species it is important to make inferences about gene flow, dispersal and population structure. In this study, we used 613 georeferenced tissue samples from hazel grouse (Bonasa bonasia) where each individual was genotyped at 12 microsatellite loci to make inference on population genetic structure, gene flow and dispersal in northern Sweden. Observed levels of genetic diversity suggest that Swedish hazel grouse do not suffer loss of genetic diversity compared with other grouse species. We found significant F(IS) (deviation from Hardy-Weinberg expectations) over the entire sample using jack-knifed estimators over loci, which is most likely explained by a Wahlund effect. With the use of spatial autocorrelation methods, we detected significant isolation by distance among individuals. Neighbourhood size was estimated in the order of 62-158 individuals corresponding to a dispersal distance of 950-1500 m. Using a spatial statistical model for landscape genetics to infer the number of populations and the spatial location of genetic discontinuities between these populations we found indications that Swedish hazel grouse are divided into a northern and a southern population. We could not find a sharp border between these two populations and none of the observed borders appeared to coincide with any potential geographical barriers.These results imply that gene flow appears somewhat unrestricted in the boreal taiga forests of northern Sweden and that the two populations of hazel grouse in Sweden may be explained by the post-glacial reinvasion history of the Scandinavian Peninsula. 相似文献
18.
The endangered Attwater's prairie chicken and an analysis of prairie grouse helminthic endoparasitism 总被引:1,自引:0,他引:1
Markus J. Peterson 《Ecography》1996,19(4):424-431
Although managers have speculated that parasitism might have contributed to the endangerment of the Attwater's prairie chicken Tympanuchus cupido attwateri , no data are available to evaluate this hypothesis. Because time is constraining, I attempted to determine whether Attwater's prairie chicken are likely to harbor helminthic endoparasites known to cause disease in other grouse so that a more informed decision regarding whether to commit time and other resources to field studies and experimental trials can be made. Using polar ordination, 1 found a gradient among 10 surveys of helminthic endoparasites of prairie grouse collected from several midcontinental ecoregions of the USA (1931 -1977). A regression model including variables representing 1) normal annual precipitation and 2) normal winter (Dec.-Feb.) temperature and the proportion of normal annual precipitation received during the winter could account for this gradient. When meteorological data from areas inhabited by the remaining 3 Attwater's prairie chicken populations were incorporated, the models predicted that Attwater's prairie chicken might be expected to harbor helminthic endoparasite communities similar to those of greater prairie chicken T. c. pinnatus populations surveyed in Illinois, Kansas, and Missouri. Two parasite species associated with disease in North American grouse Dispharynx nasuta, Heterakis gallinarum were found during these studies. Additionally, Attwater's prairie chicken might be expected to maintain parasites not found during any of the surveys I evaluated. This study suggests that it would be worthwhile to survey free-living Attwater's prairie chicken to determine whether individuals harbor helminthic endoparasites shown pathogenic to other grouse species, even if the methodologies employed must be somewhat constrained. 相似文献
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Zhiming Zhang Ruth Sherman Zijiang Yang Ruidong Wu Wenli Wang Mei Yin Guihua Yang Xiaokun Ou 《Journal for Nature Conservation》2013,21(4):225-240
Current management plans for nature reserves in China are ineffective and do not meet their intended goals of balancing conservation and development. Protected area zoning is an approach that can reduce conflict by partitioning the landscape into various land use units that are managed for different levels of human activity. In this paper, we present a systematic methodology that integrates a participatory process with Geographic Information Systems (GIS) using a multi-criteria decision analysis (MCDA) technique to guide a zoning scheme for the Meili Snow Mountain National Park (MSMNP), Yunnan. A participatory process involving multiple stakeholders and technical experts was used to establish park management objectives: nature conservation; tourism and recreation; and, community development. To meet these three objectives, criteria and impact factors for each objective were identified and weighted through a participatory process, and a GIS fuzzy set membership function was then used to generate gradient effects of each criterion. Three suitability maps of conservation, eco-tourism, and community development were generated. The three suitability maps were overlaid to generate a final combined suitability map, and five management zones (strict protected zone, ecosystem conservation zone, eco-tourism zone or buffer zone, park service zone, and traditional land use zone) were identified and mapped that corresponded to different protection and management strategies. Conservation targets (endangered species, alpine and forest ecosystems) and development zones were spatially segregated across the landscape, and the final zoning scheme was found to be acceptable by the various stakeholders. 相似文献
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