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1.
Mate-choice theory predicts different optimal mating systems depending on resource availability and habitat stability. Regions with limited resources are thought to promote monogamy. We tested predictions of monogamy in a social rodent, the hoary marmot (Marmota caligata), at the northern climatic extreme of its distribution. Mating systems, social structure and genetic relationships were investigated within and among neighbouring colonies of marmots within a 4 km(2) valley near Kluane National Park, Yukon, Canada, using 21 microsatellite loci. While both monogamous and polygynous populations of hoary marmots have been observed in the southern reaches of this species' range; northern populations of this species are thought to be predominantly monogamous. Contrary to previous studies, we did not find northern hoary marmot social groups to be predominantly monogamous; rather, the mating system seemed to be facultative, varying between monogamy and polygyny within, as well as among, social groups. These findings reveal that the mating systems within colonies of this species are more flexible than previously thought, potentially reflecting local variation in resource availability. 相似文献
2.
为了解不同地理种群喜马拉雅旱獭(Marmota himalayana)的种群数量变化并探讨其内在的遗传学机制,通过构建部分基因组文库的方法筛选出8个高变异微卫星位点,根据微卫星位点的测序结果设计相应引物,PCR扩增检测了青藏高原4个地理种群(德令哈、乌兰、沱沱河、安多)喜马拉雅旱獭的遗传多态性及其种群结构.研究结果显示:8个位点在喜马拉雅旱獭种群中均为高度多态,观察等位基因数、有效等位基因数、多态信息含量分别为4.75、3.033 2、0.610 2;喜马拉雅旱獭种群总的期望杂合度和观察杂合度分别为0.670、0.699;3个喜马拉雅旱獭种群显著(P<0.05)或极显著(P<0.01)偏离H-W平衡状态,且这些偏离平衡的位点均由杂合过度导致(FIS<0);喜马拉雅旱獭种群的部分位点已经偏离了突变-漂移平衡.结论:筛选出的8个微卫星位点适合于喜马拉雅旱獭种群遗传多样性的研究,所研究的喜马拉雅旱獭种群有较高的遗传多样性,安多地理种群在近期可能经历过瓶颈效应,种群数量曾经下降. 相似文献
3.
C. J. KYLE T. J. KARELS B. CLARK C. STROBECK D. S. HIK C. S. DAVIS 《Molecular ecology resources》2004,4(4):749-751
Microsatellite loci were developed from hoary marmots (Marmota caligata) to aid in the investigation of the social structure and mating system of this species. Seven of the microsatellite loci developed were found to be moderately polymorphic with between two and seven alleles per locus. In addition to the microsatellites developed in hoary marmots we also tested markers developed for other scuirids, namely European alpine marmots (M. marmota), Columbian ground squirrels (Spermophilus columbianus) and European ground squirrels (S. citellus). Of these markers, 13 were polymorphic when amplified in hoary marmots with between two and nine alleles per locus. 相似文献
4.
Few studies have examined the succession of plant communities in the alpine zone. Studying the succession of plant communities is helpful to understand how species diversity is formed and maintained. In this study, we used species inventories, a molecular phylogeny, and trait data to detect patterns of phylogenetic and functional community structure in successional plant communities growing on the mounds of Himalayan marmots (Marmota himalayana) on the southeast edge of the Qinghai-Tibet Plateau. We found that phylogenetic and functional diversities of plant communities on marmot mounds tended to cluster during the early to medium stages of succession, then trended toward overdispersion from medium to late stages. Alpine species in early and late stages of succession were phylogenetically and functionally overdispersed, suggesting that such communities were assembled mainly through species interactions, especially competition. At the medium and late stages of succession, alpine communities growing on marmot mounds were phylogenetically and functionally clustered, implying that the communities were primarily structured by environmental filtering. During the medium and late stages of succession the phylogenetic and functional structures of plant communities on marmot mounds differed significantly from those on neighboring sites. Our results indicate that environmental filtering and species interactions can change plant community composition at different successional stages. Assembly of plant communities on marmot mounds was promoted by a combination of traits that may provide advantages for survival and adaptation during periods of environmental change. 相似文献
5.
Kenneth B. Armitage Jaye C. Melcher John M. Ward Jr 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1990,160(5):491-502
Summary Yellow-bellied marmots characteristically live in montane-mesic environments, but in several areas in western North America, this species extended its range into lowland-xeric habitats. Body mass was significantly smaller in the lowland-xeric population from eastern Washington at 393 m than in the montane-mesic population from western Colorado at 2900 m. Oxygen consumption of marmots from montane-mesic and lowland-xeric environments was signiflcantly affected by ambient temperature (TA) water regimen, population, and a population x water regimen x temperature interaction. Lowland-xeric animals had a higher metabolic rate at low TAs, but a lower metabolic rate at higher TAs than the montane-mesic aminals. Oxygen consumption was lower on a restricted-water regimen than on ad libitum water in both populations. Coefficients relating oxygen consumption to body mass were affected by TA, water regimen, and population. These intraspecific coefficients are larger than the interspecific coefficients for all mammals. Body temperature (TB) was affected significantly by TA, water regimen, and population. TA body mass, and a population x water regimen interaction significantly affected conductance. Conductance generally was higher in the lowland-xeric than in the montane-mesic marmots. Both populations increased conductance at high TA, but the lowland-xeric population dissipated a much higher proportion of the heat by evaporative water loss (EWL) than did the montane-mesic population. Metabolic water production exceeded or equaled EWL at 5–20°C. Smaller body size, reduced metabolism at high TA, and increased EWL at high TA characterized the lowland-xeric population.Metabolic rates of yellow-bellied marmots were higher than predicted from body size during the reproductive season but decreased to 67% of that predicted from the Kleiber curve by late summer. Marmots minimize thermoregulatory costs by concentrating activity at times when the microclimate is favorable, by tolerating hyperthermia at high TA in the field, and by having a conductance lower than that predicted from body size.Abbreviations
DHC
dry-heat conductance
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EHL
evaporative heat loss
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EWL
evaporative water loss
-
HP
heat produced
-
T
A
ambient temperature
-
T
n
body temperature
-
M
body mass 相似文献
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10.
Male-caused failure of female reproduction and its adaptive value in alpine marmots (Marmota marmota) 总被引:1,自引:0,他引:1
We studied reproductive performance of free-living alpine marmots
(Marmotamarmota) for 14 years in the National Park of Berchtesgaden,
Germany.Female reproduction was influenced by body condition and social
factors.Reproduction depleted fat reserves, and only females emergingfrom
hibernation with sufficient body mass were able to reproducesuccessfully.
Marmots lived in social groups in territoriesdefended by a dominant male and
female. Subordinate femalesnever reproduced, regardless of body mass.
Territory takeoversby males impaired reproduction of dominant females, but
onlyif the takeover occurred after the mating period. Reproductivefailures
occurred despite clear signs of pregnancy such enlargednipples or late molt.
Decreasing progesterone levels after themating period and the lack of
evidence for direct infanticideby new territorial males suggest a block of
pregnancy as a likelyexplanation for reproductive failures in groups with
male takeoversduring gestation. Rendering female reproduction impossible
increasedfuture reproductive success of new territory owners. Nonparous
femalessaved the energetic cost of maternal investment and thus emergedwith
higher body mass in the following spring. In line withthis, females failing
to wean young had higher reproductivesuccess in the subsequent year. 相似文献