415 results — topic: Hydrology & Watersheds

Article

Caddisfly life histories along permanence gradients in high-altitude wetlands in Colorado (U.S.A.)

SUMMARY1. Larvae of cased caddisflies (Limnephilidae and Phryganeidae) are among the most abundant and conspicuous invertebrates in northern wetlands. Although species replacements are often observed along permanence gradients, the underlying causal mechanisms are poorly understood. In this paper, w

2003Freshwater BiologyDOI: 10.1046/j.1365-2427.2003.00997.xCited 81 times
Article

Systematic increase in pollen carryover and its consequences for geitonogamy in plant populations

W. F. Morris, M. V. Price, N. M. Waser, J. D. Thomson, B. Thomson, D. A. Stratton, Systematic Increase in Pollen Carryover and Its Consequences for Geitonogamy in Plant Populations, Oikos, Vol. 71, No. 3 (Dec., 1994), pp. 431-440

1994OikosDOI: 10.2307/3545831Cited 81 times
Article

Sackungen at the Aspen Highlands Ski Area, Pitkin County, Colorado

Research Article| January 01, 1995 Sackungen at the Aspen Highlands Ski Area, Pitkin County, Colorado JAMES P. McCALPIN; JAMES P. McCALPIN GEO-HAZ Consulting, Inc., P. O. Box 1377, Estes Park, CO 80517 Search for other works by this author on: GSW Google Scholar JAMES R. IRVINE JAMES R. IRVINE Consu

1995Environmental & Engineering GeoscienceDOI: 10.2113/gseegeosci.i.3.277Cited 80 times
Article

Temporal flexibility in the structure of plant–pollinator interaction networks

Ecological communities consist of species that are joined in complex networks of interspecific interaction. These interactions often form and dissolve rapidly, but this temporal variation is not well integrated into our understanding of the causes and consequences of network structure. If interspeci

2020OikosDOI: 10.1111/oik.07526Cited 80 times
Article

Consumptive and nonconsumptive effects of cannibalism in fluctuating age-structured populations

Theory and empirical studies suggest that cannibalism in age‐structured populations can regulate recruitment depending on the intensity of intraspecific competition between cannibals and victims and the nature of the cannibalism window, i.e., which size classes interact as cannibals and victims. Her

2010EcologyDOI: 10.1890/08-1366.1Cited 80 times
Article

Avian Risk Assessment: Effects of perching height and detectability

AbstractWe studied two components of predator risk assessment in birds. While many species are limited to seeking safety under cover or under ground, some birds can fly away from their predators and escape to trees. If birds in fact ‘feel’ safer (e.g. perceive less risk) in trees, we would expect th

2004EthologyDOI: 10.1111/j.1439-0310.2004.00970.xCited 80 times
Article

Radioactive ages of minerals from the Brown Derby Mine and the Quartz Creek Granite Near Gunnison, Colorado

Radioactive age determinations have been made on 16 minerals from the Brown Derby pegmatite and the Quartz Creek granite. A high degree of consistency has been found among the Rb-Sr ages measured on micas and feldspars. A similar degree of consistency exists in the K-A ages of micas. These consisten

1956Journal of Geophysical ResearchDOI: 10.1029/jz061i002p00215Cited 80 times
Article

Locomotor ability and wariness in yellow-bellied marmots

Animals employ a variety of behaviors to reduce or manage predation risk. Often, these are studied in isolation, but selection may act on packages of behavior that are referred to as behavioral syndromes. We focused on yellow- bellied marmots (Marmota flaviventris) and examined three commonly studied

2004EthologyDOI: 10.1111/j.1439-0310.2004.01000.xCited 80 times
Article

Yellow-bellied marmots: insights from an emergent view of sociality.

Ecological factors explain variation in sociality both within and between species of marmots—large alpine ground squirrels. Fifty years of study, by me and my colleagues, of the yellow-bellied marmots (Marmota flaviventris) at the Rocky Mountain Biological Laboratory, near Crested Butte, CO, USA, ha

2013Philosophical Transactions of the Royal Society Series BDOI: 10.1098/rstb.2012.0349Cited 80 times
Article

Behavioral ecology of alpine yellow-bellied marmots

Environmental parameters, population dynamics, resource utilization patterns, and social dynamics were evaluated in terms of their relationships to population density, intraspecific competition, parent—offspring relations, and male territoriality.

1979Behavioral EcologyDOI: 10.1007/bf00293302Cited 80 times
Article

The adaptive significance of paedogenesis in North American species of <i>Ambystoma</i> (Amphibia: Caudata): an hypothesis

Paedogenesis in varying degrees is exhibited by many species of North American salamanders, particularly of the genus Ambystoma. On the basis of a consideration of the ecology of these species, it is proposed that paedogenesis is evolutionarily adaptive and the following hypothesis is presented. In

1974Canadian Journal of ZoologyDOI: 10.1139/z74-047Cited 79 times
Article

Adaptation at specific loci. VII. Natural selection, dispersal and the diversity of molecular-functional variation patterns among butterfly species complexes (<i>Colias</i>: Lepidoptera, Pieridae)

AbstractNatural genetic variants at the phosphoglucose isomerase, PGI, gene differ in spatial patterning of their polymorphism among species complexes ofColiasbutterflies in North America. In both lowland and alpine complexes, molecular–functional properties of the polymorphic genotypes can be used

2003Molecular EcologyDOI: 10.1046/j.1365-294x.2003.01804.xCited 79 times
Article

Geology of the Urad and Henderson molybdenite deposits, Clear Creek County, Colorado, with a section on a comparison of these deposits with those at Climax, Colorado

The Urad and Henderson stockwork molybdenite orebodies at Red Mountain, Clear Creek County, Colorado, are related to a rhyolitic subvolcanic center of Oligocene age referred to as the Red Mountain Complex. The two orebodies are well separated in space and are specifically related to different intrus

1978Economic GeologyDOI: 10.2113/gsecongeo.73.3.325Cited 78 times
Article

Resource specialization in puddling Lepidoptera

Lepidoptera feed at mud puddles, dung, and carrion in a behavior known as puddling. Sodium and sometimes protein are feeding cues, are actively collected, and play a potentially important role in lepidopteran nutritional and mating ecology. We showed that montane butterfly species have feeding prefe

2004Enivornmental EntomologyDOI: 10.1603/0046-225x-33.4.1020Cited 78 times
Article

The effects of nonsugar nectar constituents on estimates of nectar energy content

1980EcologyDOI: 10.2307/1936767Cited 78 times
Article

Predicting the effects of nectar robbing on plant reproduction: implications of pollen limitation and plant mating system

The outcome of species interactions is often difficult to predict, depending on the organisms involved and the ecological context. Nectar robbers remove nectar from flowers, often without providing pollination service, and their effects on plant reproduction vary in strength and direction. In two ca

2007American Journal of BotanyDOI: 10.3732/ajb.94.12.1935Cited 78 times
Article

Germination schedules of pollen grains: implications for pollen selection

EvolutionVolume 43, Issue 1 p. 220-223 Note and CommentFree Access GERMINATION SCHEDULES OF POLLEN GRAINS: IMPLICATIONS FOR POLLEN SELECTION James D. Thomson, James D. Thomson Department of Ecology and Evolution, State University of New York at Stony Brook, Stony Brook, NY, 11794 Rocky Mountain Biol

1989EvolutionDOI: 10.1111/j.1558-5646.1989.tb04219.xCited 78 times
Article

Larval cannibalism, time constraints, and adult fitness in caddisflies that inhabit temporary wetlands

The results of the laboratory experiment suggest that this species can metamorphose with a detritus-only diet, but development is extremely protracted, which is consistent with recent growth-development models that predict coupled rather than tradeoff responses to pre-threshold manipulation of larva

2004OecologiaDOI: 10.1007/s00442-003-1397-yCited 78 times
Article

The population structure of Erebia epipsodea (Lepidoptera: Satyrinae)

The satyrine butterfly Erebia epipsodea shows a population structure unlike that of any other butterfly studied in detail. Rather than being divided into numerous small populations which only rarely exchange individuals, E. epipsodea occurs in vast, effectively panmictic populations which may cover

1970EcologyDOI: 10.2307/1933605Cited 78 times
Article

Contrasting effects of climate change on seasonal survival of a hibernating mammal.

Significance Climate change is altering the seasonal environmental conditions to which animals have adapted, but the outcome may differ between seasons for a particular species. Demographic responses therefore need disentangling on a seasonal basis to make accurate forecasts. Our study shows that cl

2020Proceedings of the National Academy of the United StatesDOI: 10.1073/pnas.1918584117Cited 77 times