Floral mimicry, coevolution of hosts and pathogens, and stress tolerance versus resistance to pathogens - B. A. Roy (Bulletin of the Geobotanical Institute ETH, 1996)

Wetlands of the Colorado River Delta Maintained by Agricultural Drainage Water - Edward P. Glenn (HortScience, 1996)
The delta of the Colorado River in Mexico historically contained 780,000 ha of riparian, marsh, and gallery forest habitat. Similar to other desert river deltas, such as the Nile and Indus, the lower delta of the Colorado River has been severely affected by the upstream diversion of water for human use. However, several large marsh areas of conservation interest still occur below the agricultural fields in Mexico. They are supported by flood water, agricultural drainage water, and municipal sewage effluent, as well as by seawater in the intertidal zone. The main anthropogenic marshes are the Rio Hardy wetland, maintained by geothermal discharge and Mexicali irrigation return flows in the western delta, and Cienega de Santa Clara, maintained by local irrigation return flows and by discharge of Wellton-Mohowk Valley drainage from the United States, imported via a 80-km canal to Mexico. These wetlands provide valuable habitat to resident and migratory waterfowl, shorebirds, mammals, and e

Colorado Potato Beetle Control; Furadan 4F Comparisons, Grand Forks, Nd, 1994 - David M. Noetzel; Jennifer Miller; Carlyle Holen (Arthropod Management Tests, 1996)
Abstract A field was planted on 11 May using certified B-sized Norchip potatoes. Soils are of a fine texture (clay), and were dry at planting time. Plots were 4 rows 36 inch wide, 25 ft. in length with a 6 ft. alley at the ends. Treatments were arranged in a RCB design, replicated 4 times. Soil treatments were applied into a trench 2 inches above the seed piece on May 11, and covered with dry soil. Foliars were broadcast in 20 gal total material at 40 psi using a hand held CO2sprayer. Application dates were 1, 28 July and 11 Aug. Conditions in July and August were very wet with standing water often present.

Colorado Potato Beetle Control; Asana Wettable Powder Efficacy Trial, Grand Forks, Nd, 1994 - David M. Noetzel; Jennifer Miller; Carlyle Holen (Arthropod Management Tests, 1996)
Abstract Certified B-sized potato seed was planted at the Red River Valley Potato Growers Research farm on 20 May. Soils were of a finely textured (clay) type. Plot size was 4 rows 36 inch wide and 25 ft. in length. Treatments were arranged in a RCB design, replicated 4 times. Insecticide application were broadcast using a hand held spray and applying at 40 psi. Dry materials were preweighed, all materials were mixed at the site and applied in 20 gal total material per acre. The trial site was extremely wet during July and August. The center two rows of each plot were harvested on 14 Oct.

Summer population structure of subalpine bats in Colorado - J. F. Storz; C. F. Williams (Southwestern Naturalist, 1996)

Biodiversity in marmots - Kenneth B. Armitage (1996)

A plant pathogen influences pollinator behavior and may influence reproduction of nonhosts - B. A. Roy (Ecology, 1996)
Some plant pathogens attract pollinating insects and thus have the potential to influence the pollination of flowers, just as different flower species can influence one another's pollination. Showy, flower—like pseudoflowers caused by the rust fungus Puccinia monoica on Arabis holboellii (Brassicaceae) commonly co—occur with flowers of Anemone patens (Ranunculaceae). I evaluated the effects of pseudoflowers and anemone on each other's visitation, and the effect of pseudoflowers on the seed set of anemone. I expected that at low overall “flower” densities visitation would be facilitated in patches containing a mixture of these species. At low densities, pseudoflowers or flowers alone may be too rare to attract sufficient visitors, but the addition of the other species could make mixtures more attractive and thus increase visitation rates. At high densities I expected that “flower” in mixtures would compete for pollinators because it is more energy efficient for pollinators to concentrat

Land Use and Landscape Change in the Colorado Mountains II: A Case Study of the East River Valley - D. M. Theobald; H. Gosnell; W. E. Riebsame (Mountain Research and Development, 1996)
D. M. Theobald, H. Gosnell, W. E. Riebsame, Land Use and Landscape Change in the Colorado Mountains II: A Case Study of the East River Valley, Mountain Research and Development, Vol. 16, No. 4 (Nov., 1996), pp. 407-418

Growth and survival of juvenile yellow-bellied marmots (Marmota flaviventris) - C. Lenihan; D. H. Van Vuren (Canadian Journal of Zoology, 1996)
We compared patterns of growth in juvenile yellow-bellied marmots (Marmota flaviventris) between 2 years in which precipitation differed, and we determined if mass at entry into hibernation affects over-winter survival. Juveniles exhibited an asymptotic growth pattern with mass gain for a mean of 60.8 days, followed by stable mass until entry into hibernation. Growth ceased in early September, shortly after the end of the plant growing season. Juveniles born in 1991, a year of late snowmelt and low summer precipitation, entered into hibernation at significantly lower mass than juveniles born in 1992. Juveniles born in 1992 survived better despite experiencing a long winter during which they spent more days in hibernation and lost more mass. Overall, heavier juveniles were more likely to survive hibernation. Further, mass at entry into hibernation apparently had a greater effect on over-winter survival than did winter severity.

Intraguild predation and cannibalism among larvae of detritivorous caddisflies in subalpine wetlands - S. A. Wissinger; G. B. Sparks; G. L. Rouse; W. Brown; Heidi Steltzer (Ecology, 1996)
Comparative data from subalpine wetlands in Colorado indicate that larvae of the limnephilid caddisflies, Asynarchus nigriculus and Limnephilus externus, are reciprocally abundant among habitats–Limnephilus larvae dominate in permanent waters, whereas Asynarchus larvae dominate in temporary basins. The purpose of this paper is to report on field and laboratory experiments that link this pattern of abundance to biotic interactions among larvae. In the first field experiment, growth and survival were compared in single and mixed species treatments in littoral enclosures. Larvae, which eat mainly vascular plant detritus, grew at similar rates among treatments in both temporary and permanent habitats suggesting that exploitative competition is not important under natural food levels and caddisfly densities. However, the survival of Limnephilus larvae was reduced in the presence of Asynarchus larvae. Subsequent behavioral studies in laboratory arenas revealed that Asynarchus larvae are extr

Evolution of floral traits in a hermaphroditic plant: field measurements of heritabilities and genetic correlations - Diane R. Campbell (Evolution, 1996)
Genetic variances, heritabilities, and genetic correlations of floral traits were measured in the monocarpic perennial Ipomopsis aggregata (Polemoniaceae). A paternal half-sib design was employed to generate seeds in each of four years, and seeds were planted back in the field near the parental site. The progeny were followed for up to eight years to estimate quantitative genetic parameters subject to natural levels of environmental variation over the entire life cycle. Narrow-sense heritabilities of 0.2-0.8 were detected for the morphometric traits of corolla length, corolla width, stigma position, and anther position. The proportion of time spent by the protandrous flowers in the pistillate phase ("proportion pistillate") also exhibited detectable heritability of near 0.3. In contrast, heritability estimates for nectar reward traits were low and not significantly different from zero, due to high environmental variance between and within flowering years. The estimates of genetic param

Insect herbivory as a major factor in the shade distribution of a native crucifer (Cardamine cordifolia A. Gray, bittercress) - S. M. Louda; J. E. Rodman (Journal of Ecology, 1996)
Svata M. Louda, James E. Rodman, Insect Herbivory as a Major Factor in the Shade Distribution of a Native Crucifer (Cardamine Cordifolia A. Gray, Bittercress), Journal of Ecology, Vol. 84, No. 2 (Apr., 1996), pp. 229-237

Colonization and reproduction of the epibiotic flagellate Colacium vesiculosum (Euglenophyceae) on Daphnia pulex - R. S. Al-Dhaheri; R. L. Willey (Journal of Phycology, 1996)
ABSTRACTThe epibiotic flagellate Colacium vesiculosum Pringsheim attaches to planktonic species of Daphnia in freshwater habitats. Previous studies found that prevalence (percentage of substrate organisms carrying attached epibionts) and intensity (number of attached epibionts on a given substrate organism) are low early in the Daphnia intermolt period and are high late in the intermolt period. We tested the hypothesis that increases of Colacium cells attached to Daphnia occur both by rapid initial and continuous colonization and by cell reproduction. Epibiont prevalence and intensities were determined at successive intermolt stages of Daphnia pulex Leydig collected from freshwater ponds in Colorado. Colonization was continuous throughout the intermolt period and was most important to epibiont population increase at the beginning of the intermolt period. Cell division was the major contributor to epibiont increase at the end of the intermolt period.

The effect of mermithid parasitism on the behavior and ecology of its mayfly host - S. A. Vance (1996)

The ant/plant relationship of Formica and Helianthella - S. Merz (1996)

Prevalence of chiropteran predation by owls of the Gunnison County region - S. Merideth (1996)

The species-area relationship and spatial turnover - S. McCarthy (1996)

The effect of size and morphology on the foraging behavior of Ambystoma tigrinum nebulosum - E. Johnson (1996)

Biodiversity of insect families in three montane habitats - K. Jakubowski (1996)

Biodiversity in marmots - Kenneth B. Armitage; Kenneth B. Armitage; Kenneth B. Armitage (1996)

Sexual dimorphism in tiger salamanders of the kettle ponds of Gothic, Colorado - M. Holderby (1996)

Correlation between insect abundance and foraging activity of the sub-alpine bats of Gothic, Colorado - S. Harney (1996)

Foraging and vigilance behavior of social and solitary female marmots - G. Graham (1996)

Vascular plant species of talus slope and their dispersal patterns - M. Bateman (1996)

Queen-queen interaction as it related to dominance in polygynous colonies of Myrmica tahoensis - E. Von Wettburg (1996)

Does pollination matter to Polygonum douglasii? - R. Robles (1996)

Adaptation at specific loci. VI. Divergence vs parallelism of polymorphic allozymes in molecular function and fitness-component effects among Colias species (Lepidoptera:Pieridae) - W. B. Watt; K. Donohue; P. A. Carter (Molecular Biology and Evolution, 1996)

The effect of the mermithid parasite Gasteromermis sp. (Nematoda: Mermithidae) on the drift behaviour of its mayfly host, Baetis bicaudatus (Ephemeroptera: Baetidae): a trade-off between avoiding pred - S. A. Vance (Canadian Journal of Zoology, 1996)

Using species-area relationship to determine species turnover in terrestrial arthropods - R. Salinas (1996)

A population census and study of interspecific competition between Nicrophorus investigator and Nicrophorus defodiens - S. Richmond (1996)

Microdistributions, food resources and feeding habits of filter-feeding Trichoptera in the Upper Colorado River - Neal J. Voelz; J. M. Ward (Archiv für Hydrobiologie, 1996)
A year-round study was conducted in the Colorado River, USA, to examine microdistributions and feeding habits of the filter-feeding Trichoptera (caddisflies) Arctopsyche grandis, Brachycentrus occidentalis and Hydropsyche cockerelli. Only one significant relationship was found between individual rock surface area and the density of larvae during the sampling periods. Contrary to our predictions that current exposed microhabitats would be selected, all species occurred primarily on the bottom and lower lateral sides of rocks at all sites. Clumped distributions in the absence of spatial segregation by size class suggest common microhabitat preferenda for species and instars. Organic seston in the study reach consisted primarily of detritus, diatoms and Closterium sp. (a green alga). The diets of B. occidentalis and H. cockerelli generally corresponded with the obs

Foraging efficiency as related to variance in worker size and colony size in Formica neorufibarbis - L. McClenachan (1996)

Benefits of coloniality: increased foraging frequency through the use of information centers in a cliff swallow colony - W. A. Jordan (1996)

Phenotypic plasticity and resource allocation in the leaves of Geranium richardsonii, Mertensia ciliata, and Valeriana occidentalis in a sun dominant versus a shade dominant habit - K. Jakubowski (1996)

Noteworthy collections: Colorado - R. Seagrist; K. J. Taylor (Madro¤o, 1996)

Growth and foraging consequences of facultative paedomorphosis in the tiger salamander, Ambystoma tigrinum nebulosum - H. H. Whiteman; S. A. Wissinger; W. Brown (Evolutionary Ecology, 1996)

Mating systems and sexual division of foraging effort affect puddling behavior by butterflies - C. E. Sculley; C. L. Boggs (Ecological Entomology, 1996)
Abstract. 1. Foraging effort can vary among age classes and between the sexes. In many Lepidoptera, young males feed from mud, dung or carrion in a behaviour known as ‘puddling’, whereas females rarely puddle. In at least one species, males transfer sodium gained from puddling to females at mating for use in egg production. 2. Here we examine sex‐ and age‐specific puddling patterns in seven montane butterfly species. We also test the hypothesis that among species in which young males predominate at puddles, differences in age‐ and sex‐specific puddling patterns for a given species are related to mean female lifetime mating numbers. 3. For five species, young males fed proportionately more at puddles than other sex and age classes. Two species showed anomalous feeding patterns. In one, young females predominated at puddles; in the other, butterflies were rarely found at flowers. 4. As predicted,

Effects of human-made trails on local vegetative diversity - P. Higuera (1996)

Species diversity and evenness of benthic invertebrates as a measure of the effects of pollution from Gothic campground - J. Greshko (1996)

Mechanisms of hummingbird-mediated selection for flower width in Ipomopsis aggregata - Diane R. Campbell; Nickolas M. Waser; Mary V. Price (Ecology, 1996)

Stoneflies as ecological engineers - hungry predators reduce fine sediments in stream beds - B. A. Zanatell; B. L. Peckarsky (Freshwater Biology, 1996)

The infection of nymphal Baetis bicaudatus by the mermithid nematode Gasteromermis sp - S. A. Vance; B. L. Peckarsky (Ecological Entomology, 1996)

Alternative predator avoidance syndromes of stream-dwelling mayfly larvae - B. L. Peckarsky (Ecology, 1996)
Experiments were conducted to compare the patterns, mechanisms, and costs of predator avoidance behavior among larvae of five species of mayflies that co—occur with the predatory stoneflies, Megarcys signata and Kogotus modestus in western Colorado streams. Mayfly drift dispersal behavior, use of high vs. low food (periphyton or detritus) patches, microhabitat use, positioning, and activity periodicity were observed in the presence and absence of predators in circular flow—through chambers using natural stream water. Also, distances from predators at which prey initiated escape responses were compared among prey and predator species. Costs of predator avoidance behavior were assessed by measuring short—term (24 h) feeding rates of mayflies in the presence or absence of predatory stoneflies whose mouthparts were immobilized (glued) to prevent feeding. The intensity and associated costs of predator avoidance behavior of mayfly species were consistent with their relative rates of predatio

High-temperature tolerance of Artemisia tridentata and Potentilla gracilis under a climate change manipulation - M. E. Loik; J. Harte (Oecologia, 1996)

Effects of manipulated soil microclimate on mesofaunal biomass and diversity - J. Harte; A. Rawa; V. Price (Soil Biology and Biochemistry, 1996)

A comparison of vegetational maturity and succession rates in an avalanche area - C. R. Whitney (1996)

Morphological and behavioral sex reversal in mermithid-infected mayflies - S. A. Vance (Proceedings of the Royal Society of London, 1996)

Competition and relatedness between queens of the facultatively polygynous ant Myrmica tahoensis - J. D. Evans (Animal Behaviour, 1996)

Solitary behavior in a high-altitude population of the social sweat bee Halictus rubicundus (Hymenoptera: Halictidae) - M. A. Eickwort; M. A. Eickwort; JAMES H. Gordon; M. A. Eickwort (Behav Ecol Sociobiol, 1996)

Fluctuating asymmetry and reproductive successin Delphinium nelsonii - L. Bone (1996)

Floral biology - P. Wilson; J. D. Thomson (1996)

Distribution and habitat characterization of subalpine chiropteran species - M. A. Garza (1996)

A new horizon for biological field stations and marine laboratories - S. Lohr; P. G. Connors; J. S. Clegg; J. Stanford; J. Stanford; S. Lohr (Trends in Ecology and Evolution, 1996)

Detectability, philopatry, and the distribution of dispersal distances in vertebrates - W. D. Koenig; D. H. Van Vuren; P. N. Hooge (Trends in Ecology and Evolution, 1996)
The inadequacy of dispersal data obtained directly by traditional methods using population studies of marked individuals is highlighted by comparing the resulting distributions with dispersal estimates obtained by radio-tracking and by using genetic estimates of gene flow.

Temporal and spatial variation in reproduction in the facultatively polygynous ant Myrmica tahoensis (Hymenoptera: Formicidae) - J. D. Evans (Ins. Soc., 1996)

Male reproductive success and variation in fruit and seed set in Aquilegia carerulea (Ranunculaceae) - J. Brunet (Ecology, 1996)

Queen longevity, queen adoption, and posthumous indirect fitness in the facultatively polygynous ant Myrmica tahoensis - J. D. Evans (Behavioral Ecology, 1996)

Avalanche intensity and the intermediate disturbance hypothesis - M. Geluardi (1995)

Postfertilization causes of differential success of pollen donors in Erythronium grandiflorum (Liliaceae): Nonrandom ovule abortion - L. P. Rigney (American Journal of Botany, 1995)

Selection on flower color in an Ipomopsis hybrid zone - E. J. Melendez (1995)

Epibiont populations on Daphnia: effects of habitat patch dispersion on metapopulation dynamics - D. A. Chiavelli (1995)

The influence of different types of disturbance on insect diversity - C. H. Sekercioglu (1995)

Carcass selection in a high altitude population of the burying beetle, Nicrophorus investigator, (Silphidae) - R. J. Smith; B. Heese (Southwestern Naturalist, 1995)

The effect of sediment load on aquatic invertebrate diversity in beaver ponds - I. Behrens (1995)

Impacts of recreational boating on freshwater invertebrates - J. L. Hayes (1995)

Report on the conservation status of Veratrum californicum in the Gothic area - M. Hristova (1995)

Change in terrestrial vegetation and the relating consequences for stream communities - J. Karem; M. McKnight; J. L. Hayes; D. Engelberg (1995)

Study of dust accumulation on roadside vegetation along Gothic Road - M. Pengra (1995)

Status of Mustela frenata in the Gothic area - T. Tanner (1995)

An investigation of the effects of pH, aluminum precipitate, and periphyton densities on benthic invertebrate populations in Paradise Basin, Colorado - S. Feldhousen (1995)

Patterns and mechanisms of invasion of conifer (Abies lasiocarpa and Picea engelmanni) into aspen forest and montane meadow - J. Downing; J. Harte (1995)

Surveying beavers around RMBL and how effective are beaver ponds as sediment traps - I. Behrens (1995)

Predatory and parasitic Lepidoptera: carnivores living on plants - N. E. Pierce (Journal of the Lepidoptera Society, 1995)

Shifting dominance within a montane vegetation community: results from a climate-warming experiment - J. Harte; R. G. Shaw (Science, 1995)
In experimentally heated plots that each span a soil moisture gradient in a Rocky Mountain meadow, aboveground biomass of Artemisia tridentata (a sagebrush) increased in the drier habitat and that of Pentaphylloides floribunda (a shrub cinquefoil) increased in the wetter habitat relative to control plots. In contrast, aboveground forb biomass decreased in the wet and dry habitats of the heated plots. These results, combined with evidence for enhanced sagebrush seedling establishment rates in the heated plots, suggest that the increased warming expected under an atmosphere with a concentration of carbon dioxide twice that of pre-industrial levels could change the dominant vegetation of a widespread meadow habitat.

Relatedness threshold for the production of female sexuals in colonies of a polygynous ant, Myrmica tahoensis, as revealed by microsatellite DNA analysis - J. D. Evans (Proceedings of the National Academy of Sciences, USA, 1995)
The genetic relationships of colony members in the ant Myrmica tahoensis were determined on the basis of highly polymorphic microsatellite DNA loci. These analyses show that colonies fall into one of two classes. In roughly half of the sampled colonies, workers and female offspring appear to be full sisters. The remaining colonies contain offspring produced by two or more queens. Colonies that produce female sexuals are always composed of highly related females, while colonies that produce males often show low levels of nestmate relatedness. These results support theoretical predictions that workers should skew sex allocation in response to relatedness asymmetries found within colonies. The existence of a relatedness threshold below which female sexuals are not produced suggests a possible mechanism for worker perception of relatedness. Two results indicate that workers use genetic cues, not queen number, in making sex-allocation decisions. (i) The number of queens in a colony was not

Colorado Mathematical Olympiad: The first 10 years and further explorations, by Alexander Soifer. Pp 188. $19.95. 1994. ISBN 0- 940263-03-3 (Center for Excellence in Mathematical Education, 855 Red Mesa Drive, Colorado Springs CO80906, USA) - Steve Abbott (The Mathematical Gazette, 1995)
Colorado Mathematical Olympiad: The first 10 years and further explorations, by Alexander Soifer. Pp 188. $19.95. 1994. ISBN 0- 940263-03-3 (Center for Excellence in Mathematical Education, 855 Red Mesa Drive, Colorado Springs CO80906, USA) - Volume 79 Issue 484

Size and abundance: breeding population density of the Calliope Hummingbird - L. L. Calder; L. L. Calder (Auk, 1995)
BENT, A. C. 1942. Life histories of North American flycatchers, larks, swallows and their allies. U.S. Natl. Mus. Bull. 179. BUDD, L. F., R. B. AREND, J. W. HURST, AND V. H. ANDERSON. 1979. Fort Bliss environmental analysis and impact assessment. Photographic Interpretation Corporation, Hanover, New Hampshire. BUTLER, R. W. 1980. Appropriation of an American Robin nest by Dark-eyed Juncos. Can. Field Nat. 94:197. BUTLER, R. W., AND C. A. CAMPBELL. 1987. Nest appropriation and interspecific feeding between Tree Swallows, Tachycineta bicolor, and Barn Swallows, Hirundo rustica. Can. Field-Nat. 101:433-434. EHRLICH, P. R., D. S. DOBKIN, AND D. WHEYE. 1988. The birder's handbook. Simon and Schuster, New York. EMLEN, S. T., AND S. L. VEHRENCAMP. 1983. Cooperative breeding strategies among birds. Pages 93-120 in Perspectives in ornithology (A. H. Brush and G. A. Clark, Jr., Eds.). Cambridge Univ. Press, Cambridge. GIBBONS, D. W. 1986. Brood parasitism and cooperative nesting in the Moorhen,

The Unsolicited Chronicler: An Account of the Gunnison Massacre, Its Causes and Consequences, Utah Territory, 1847-1859. - James B. Allen; Robert Kent Fielding (The Journal of American History, 1995)
Journal Article The Unsolicited Chronicler: An Account of the Gunnison Massacre, Its Causes and Consequences, Utah Territory, 1847–1859. By Robert Kent Fielding. (Brookline: Paradigm, 1993. xiv, 474 pp. $49.95, ISBN 0-912111-38-0.) Get access James B. Allen James B. Allen Emeritus Brigham Young University, Provo, Utah Search for other works by this author on: Oxford Academic Google Scholar Journal of American History, Volume 81, Issue 4, March 1995, Pages 1718–1719, https://doi.org/10.2307/2081719 Published: 01 March 1995

Tests of pollen viability in hand-pollination experiments: a literature review - J. Stone; J. D. Thomson; S. Dent-Acosta (American Journal of Botany, 1995)

Management of mule deer in edge habitats - R. Crafts (1995)

Middle Jurassic Todilto Formation of northern New Mexico and southwestern Colorado: Marine or nonmarine? - D. W. Kirkland; R. E. Denison; R. Evans (1995)
Resolution of the controversy about the origin of this evaporitic limestone and gypsum unit is possible only if the position that the Todilto is exclusively marine or exclusively nonmarine is abandoned. The Todilto Formation was deposited in a coastal body of saline water (a salina) adjacent to the Sundance Sea. After an initial flooding by marine water, the salina was maintained by inflow of fresh water from streams, mostly intermittent, and by influx of sea water by seepage through or over-topping of physiographic barriers. The arid climate promoted evaporation, which led to precipitation of laminated carbonates and nodular gypsum. The mixed brine gave its precipitates a distinctive and indelible isotopic signature-the carbon and sulfur isotopic ratios could be interpreted as originating from marine waters, the strontium ratios as being influenced by nonmarine waters. Reconstruction of the Todilto paleoenvironment as a salina reconciles the apparent conflicts in interpretation of che

Lichen diversity in aspen edge and spruce-fir edge - K. D. Craig (1995)

Oviposition preferences in the sharp-veined white butterfly, Pieris napi - V. Ezenwa (1995)

Can montane landscapes recover from human disturbance? Long-term evidence from disturbed subalpine communities - C. G. Curtin (Biological Conservation, 1995)
It is found that, after over 100 years, these disturbed plant communities remained distinct from similar surrounding undisturbed areas, suggesting that biotic factors structure vegetation communities even hundreds of years following disturbance.

Ecological restoration through behavioral change - J. Cairns; J. R. Pratt (Restoration Ecology, 1995)

Cheaters never prosper. Or do they? - S. Magana (1995)

A comparative study: water chemistry, species richness and abundance in freshwater springs of Gunnison County - A. Hultgren; B. Morrison; K. Krakauer; M. Arreguin; B. Roe (1995)

An exploration of the effects of ant-aphid interaction on host plant growth - E. K. Jewett (1995)

Sackungen at the Aspen Highlands Ski Area, Pitkin County, Colorado - J. P. McCALPIN; J. R. IRVINE (Environmental & Engineering Geoscience, 1995)
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 Consulting Soil Scientist 182 County Road 24, Ridgway, CO 81432 Search for other works by this author on: GSW Google Scholar Environmental & Engineering Geoscience (1995) I (3): 277–290. https://doi.org/10.2113/gseegeosci.I.3.277 Article history first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation JAMES P. McCALPIN, JAMES R. IRVINE; Sackungen at the Aspen Highlands Ski Area, Pitkin County, Colorado. Environmental & Engineering Geoscience 1995;; I (3): 277–290. doi: https://doi.org/10.2113/gseegeosci.I.3.277 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers En

Structure-activity relationships of norditerpenoid alkaloids occurring in toxic larkspur Delphinium species - G. D. Manners; K. E. Panter; S. W. Pelletier (Journal of Natural Products, 1995)

Hierarchical analysis of allozymic and morphometric variation in a montane herb, Ipomopsis aggregata (Polemoniaceae) - P. G. Wolf; Diane R. Campbell (Journal of Heredity, 1995)

Costs and benefits of sociality in yellow-bellied marmots (Marmota flaviventris): do noncolonial females have lower fitness? - C. Lenihan (1995)

A new horizon for biological field stations and marine laboratories - S. Lohr; P. G. Connors; J. Stanford; J. S. Clegg (1995)

A comparison of resource allocation to reproduction and pollinator visitation to Delphinium nelsonii and Lupinus argentis - C. Kokesh (1995)

The core of the Black Canyon Computer Corporation - J. Couleur (IEEE Annals of the History of Computing, 1995)
The author discusses his experiences with the GEC computer department, starting with the M236, a high speed 36-bit minicomputer. He discusses the GE 600 lineage, the GE 600/645 and paging, tape transport problems, and the end of the department.

Hierarchical Analysis of Allozymic and Morphometric variation in a Montane Herb, Ipomopsis Aggregata - Diane R. Campbell; P. G. Wolf (Journal of Heredity, 1995)

Control of Colorado Potato Beetle in the Red River Valley, Grand Forks, ND, 1994 - Robert A. Suranyi; Edward B. Radcliffe; Matthew P. Samuelson; Galen C. Thompson (Arthropod Management Tests, 1995)
Abstract Potatoes were planted 17 May at the Research Farm of the Red River Valley Potato Growers Association. Plots were four rows wide, 60 ft long, with 38 in rows and 12 in between plants. Plots were separated on all sides by 6.3 ft of cultivated soil. The experiment had a complete randomized plot design with four replications. Egg masses were flagged 15 Jun and checked daily. Thirty percent egg hatch was estimated to have occurred 22 Jun, but heavy rains and wet field conditions delayed first application of insecticidal sprays until 24 Jun. Subsequent spray applications were made 5, 12 Jul, and 8 Aug. Jun and Jul sprays were targeted against first generation larvae, Aug application against summer generation adults. All applications were made using a tractor-mounted boom sprayer, with a single Teejet nozzle over each row. Sprays were applied in 40 gal of water/acre at 40 psi. Egg masses, small larvae (1st and 2nd instar), large larvae (3rd and 4th instar), and adults

Hydrological effects of hypothetical climate change in the East River basin, Colorado, USA - Gregory J. McCabe; LAUREN E. Hay (Hydrological Sciences Journal, 1995)
Abstract In 1988, the US Geological Survey began a study of the effects of potential climate change on the water resources of the Gunnison River basin. The Gunnison River, in southwestern Colorado, is an important tributary of the Colorado River, contributing approximately 40% of the flow of the Colorado River at the Colorado/Utah stateline. As part of the study, the sensitivity of annual and seasonal runoff in the East River basin, a sub-basin of the Gunnison River basin, to changes in temperature and precipitation was examined. To perform the sensitivity analyses, hypothetical climate changes were used to alter current time series of temperature and precipitation. The altered time series were then used as inputs to a hydrological model that translated these inputs into estimates of runoff. Mean annual and seasonal runoff resulting from a range of hypothetical climate changes were compared and evaluated. Results indicated that in general, changes in precipitation had a larger effect o

Facultative polygyny in the ant Myrmica tahoensis - J. D. Evans (1995)

Plant community structure as a function of grazing by cattle - M. Trout (1995)

Oviposition patterns and larval success of a pre-dispersal seed predator attacking two confamilial host plants - Alison K. Brody; Nickolas M. Waser (Oikos, 1995)
Phytophagous insects that deposit eggs directly on hosts confront a plant world of variable quality. Some studies to date provide evidence for positive relationships between the site of oviposition and offspring success, as expected if females choose sites of high quality or if they or their offspring manipulate host physiology. We studied relationships between oviposition site and larval success for the anthomyiid fly Hyle-mya sp., a predispersal seed predator of the confamilial montane plants Polemonium foliosissimum and Ipomopsis aggregata. The intensity of oviposition on a given P. foliosissimum plant was a good predictor of attack in the following year, suggesting choosiness of female flies. However, larval survival did not decline detectably when eggs were transferred among flowers within or between plants, compared to survival where the female fly originally had deposited the eggs. Also, P. foliosissimum flowers with eggs did not have a higher probability of setting fruit than t

The reproductive outputs of Delphinium nelsonii at differing elevations - J. Schiller (1995)

Seed set and seed mass in Ipomopsis aggregata: variance partitioning and inferences about postpollination selection - Nickolas M. Waser; R. G. Shaw; Mary V. Price (Evolution, 1995)
Events that follow pollination, such as pollen-tube growth and seed maturation, comprise an important phase of angiosperm reproduction. Differential success during this "postpollination" phase may represent phenotypic selection, including sexual selection, or interaction between parents caused, for example, by their genetic similarity. By providing a detailed partitioning of variance in success, diallel crossing designs offer great potential to determine which processes are occurring and their relative magnitudes. We performed three partial diallels with the montane herb Ipomopsis aggregata, using a large sample of parental plants (69 total). Embedded in the designs were crossing-distance treatments of 1 m, 10 m, and 100 m, reflecting a range of parental genetic similarity. We partitioned phenotypic variance in seed set per fruit into six components using restricted maximum-likelihood (REML) analysis. For one diallel, we also partitioned variance in seed mass into five components, and

Exploitation of lycaenid-ant mutualisms by braconid parasitoids - K. Fiedler; P. Seufort; N. E. Pierce; J. G. Pearson; T. Baumgarten (Journal of Research on the Lepidoptera, 1995)
Larvae of 17 Lycaenidae butterfly species from Europe, North America, South East Asia and Australia were observed to retain at least some of their adaptations related to myrmecophily even after parasitic braconid larvae have emerged from them. The myrmecophilous glandular organs and vibratory muscles of such larval carcasses remain functional for up to 8 days. The cuticle of lycaenid larvae contains extractable "adoption substances" which elicit antennal drumming in their tending ants. These adoption substances, as well, appear to persist in a functional state beyond parasitoid emergence, and the larval carcasses are hence tended much like healthy caterpillars. In all examples, the braconids may receive selective advantages through myrmecophily of their host larvae, instead of being suppressed by the ant guard. Interactions where parasitoids exploit the ant-mutualism of their lycaenid hosts have as yet been recorded only from the Apanteles group in the Braconidae-Microgasterinae .

Microhabitat and activity periodicity of predatory stoneflies and their mayfly prey in a western Colorado stream - B. L. Peckarsky; C. A. Cowan (Oikos, 1995)
Experiments were conducted to determine whether overlap between microhabitat preferences and activity periodicities of four mayfly species and their stonefly predators could explain species-specific differences in predator-prey encounter frequencies. Preferences for rock type (slate or granite), flow microhabitat (high or low), rock surface (top, bottom, upstream or downstream sides), and periodicity of drift and the use of rock tops were measured in a stream-side system of flow-through circular Plexiglas chambers receiving natural stream water and light levels. These parameters were compared among the predatory stoneflies, Megarcys signata or Kogotus modestus, and four species of mayflies that vary in their encounter rates with the stoneflies. Based on predator-prey encounter rates previously observed in similar chambers, we expected greater overlap between Megarcys and Ephemerella infrequens and the overwintering generation of the bivoltine mayfly, Baetis bicaudatus than with Cinygmu

Correlation of environmental parameters and insect abundance to bat foraging patterns - M. E. P. Vieira (1995)

Effects of avalanche intensity on Populus tremuloides density - L. P. Hoover (1995)

The breeding systems of six species of Arabis (Brassicaceae) - B. A. Roy (American Journal of Botany, 1995)
The ability of organisms to produce genetic variation for any trait, including resistance to pathogens, is partially determined by breeding system. I used enzyme electrophoresis, crossing experiments, and cytology to assess the breeding systems of cooccurring Arabis species that are often infected by rust fungi. The Arabis holboellii surveyed were pseudogamous apomicts with relatively high population‐level ailozyme variation, and variable chromosome numbers (2n, 3n, 4n). Arabisgunnisoniana (3n) and Arabis lignifera (2n) were also pseudogamous but showed no allozyme variation either at the population level, or within progeny arrays. Arabis hirsuta may be an autogamous polyploid or it may be a pseudogamous apomict; more work is needed to clarify the breeding system of this species. Arabis drummondii and Arabis crandallii were sexual, but exhibited little genetic variability due to a predominance of self‐fertilization. The use of several techniques was necessary to evaluate these breeding

Seed dispersal in Erythronium grandiflorum (Liliaceae) - G. D. Weiblen; J. D. Thomson (Oecologia, 1995)
The lack of a special seed dispersal mechanism in E. grandiflorum is discussed in terms of a source-sink model for seedling establishment with respect to distance from the parental plants, which yields a more complete estimate of Wright's neighborhood size, Ne.

Estimates of mayfly mortality: is stonefly predation a significant source? - B. L. Kerans; B. L. Peckarsky; C. Anderson (Oikos, 1995)
Kerans, B. L., Peckarsky, B. L. and Anderson, C. 1995. Estimates of mayfly mortality: is stonefly predation a significant source? - Oikos 74: 315-323. Field experiments and surveys were canied out in a Rocky Mountain alpine stream during the summers of 1990 and 1992 to estimate the proportion of natural losses of the mayfly Baetis bicaudatus resulting from the co-occurring, predatory stonefly, Kogotus modestus. Functional response experiments determined the number of prey consumed by male and female Kogotus by manipulating the densities of prey and the presence or absence of predators in stream-side chambers. Estimates of losses of Baetis and density of Kogotus were based on ten benthic samples collected weekly (except for last sampling date) from one study reach. Concurrently, drift density of Baetis was estimated upstream and downstream of the reach to determine gains or losses of Baetis resulting from migration. In the functional response experiments Kogotus consumed the same number

Global warming and soil microclimate: results from a meadow-warming experiment - J. Harte; M. S. Torn; F. R. Chang; B. P. Feifarek; A. Kinzig; R. G. Shaw; K. P. Shen (Ecological Applications, 1995)
We used overhead infrared radiators to add a constant increment of °15 W/m2, over 2 yr, to the downward heat flux on five 30‐m2 montane meadow plots in Gunnison County, Colorado, USA. Heating advanced snowmelt by °1 wk, increased summer soil temperatures by up to 3°C, and reduced summer soil moisture levels by up to 25% compared to control plots. Soil microclimate response to heating varied with season, time of day, weather conditions, and location along the microclimate and vegetation gradient within each plot, with the largest temperature increase observed in daytime and in the drier, more sparsely vegetated zone of each plot. Day‐to‐day variation in the daily‐averaged temperature response to heating in the drier zone was negatively correlated with that in the wetter zone. Our experimental manipulation provides a novel and effective method for investigating feedback processes linking climate, soil, and vegetation.

Floral sex allocation in sequentially blooming plants - J. Brunet; D. Charlesworth (Evolution, 1995)
In plants whose flowers develop in a sequence, different flowers may exhibit temporal variation in pollen donation and receipt such that the fitness contributions through male and female functions can vary among flowers. Dichogamy, or directional pollinator movements within inflorescences, can create situations where flowers in different stages in the sequence may differ in the numbers of flowers in the female stage available as potential mates. We present an evolutionarily stable strategy (ESS) analysis of the resource allocations expected in different flowers in hermaphroditic plants when the mating environments vary among flowers. This introduces a modular element into sex-allocation models. Our analysis shows that such variation in the mating environments of flowers can select for differences in sex allocation between flowers. When male and female fertilities are nonlinear functions of the allocations, variation in resource availability can also select for variation in sex allocati

Pollinator effectiveness of Mertensia fusiformis, Delphinium nelsonii, and D. barbeyii: is there one best pollinator to which the plant is adapted? - J. J. Gannon (1995)

Management of Molothrus ater in Gothic, Colorado - S. Nayak (1995)

Harvest rates and escape speeds in two coexisting species of montane ground squirrels - R. J. Smith (Journal of Mammalogy, 1995)
I measured harvest rates and maximum running-escape speeds of two species of ground-dwelling squirrels, the least chipmunk (Tamias minimus) and the golden-mantled ground squirrel (Spermophilus lateralis). Using seed trays in which foragers experienced diminishing returns, I found that S. lateralis harvested seeds faster than did T. minimus. This difference was due to a significantly higher rate of encounter of seeds by S. lateralis. There was no significant difference in handling times between species. Higher harvest rates may reduce predation risk by decreasing the amount of time spent exposed to predators while foraging. I also measured maximum running speeds by chasing animals over short distances. I found that S. lateralis ran significantly faster than did T. minimus (3.14 and 2.13 m/s, respectively). A faster maximum running speed could enable S. lateralis to escape pursuit, but also to exploit the meadow habitat farther from the safety of the forested edge. In previous studies, I

Reproductive energetics of adult male yellow-bellied marmots (Marmota flaviventris) - C. M. Salsbury; Kenneth B. Armitage (Canadian Journal of Zoology, 1995)
We examined the energy expenditure of adult male yellow-bellied marmots (Marmota flaviventris) and its relationship to various female-defense characteristics critical to male reproductive success. Resting metabolic rates of males were estimated in the laboratory via oxygen-consumption analysis, and field metabolic rates were estimated using a doubly labeled water technique. Male home-range size, number of females defended by males, dispersion of females in the habitat, and date into the active season were considered to be predictors of male energy expenditure in excess of maintenance costs (field metabolic rate minus resting metabolic rate). Energy expenditure was best explained by a defensibility index based on the number and dispersion of females defended; expenditure increased with number and dispersion of females. Energy expenditure increased with date into the active season. Environmental constraints on male activity during the mating season may have led to a shift in male reprodu

Behavioral responses to predation risk: survival strategies of the golden-mantled ground squirrel - R. Carnevale (1994)

Geological hazards, vulnerability, and risk assessment using GIS: model for Glenwood Springs, Colorado - Mario Mejía-Navarro; Ellen Wohl; Sherry Oaks (Elsevier eBooks, 1994)

Spatial navigation in natural habitats by ground-dwelling sciurids - L. D. Devenport; L. D. Devenport (Animal Behaviour, 1994)

Benefits of restoration on abandoned roads at high altitude: minimizing the impacts of habitat fragmentation - J. F. Burkhart (1994)

Pollinator restriction in the narrow-tube flower type of Mertensia ciliata (James) G. Don (Boraginaceae) - K. Suzuki (Plant Species Biology, 1994)

The effects of pathogen-induced pseudoflowers and buttercups on each other's insect visitation - B. A. Roy (Ecology, 1994)
Pseudoflowers induced by the rust fungus Puccinia monoica on Arabis spp. are flower—like in color, shape, size, nectar production, and scent. Pseudoflowers attract insects that aid the rust's reproduction in a way that is analogous to pollination in flowering plants. I explored the effects of pathogen—induced pseudoflowers and co—blooming buttercups (Ranunculus inamoenus) on each other's insect visitation by comparing visitation in single—species plots and mixtures. Visitation to pseudoflowers was greater in mixtures containing buttercups than in pseudoflowers plots of the same density, and visitation to buttercups was also greater in the mixtures than in pure buttercup plots. Because fungal pseudoflowers and buttercups both appeared to receive greater visitation when associated with each other than when alone, and both species produce food for insect visitors, this interaction could be described as Mullerian floral mimicry. However, several characteristics of this system do not fit st

Non-visual communication in freshwater benthos: an overview - S. I. Dodson; T. A. Crowl; B. L. Peckarsky; L. B. Kats; A. P. Covich; J. N. Culp (Journal of the North American Benthological Society, 1994)
This overview of non-visual communication in freshwater benthic animals emphasizes recent studies of the effect of chemical and mechanical signals on predator-prey interactions of benthic macroinvertebrates and amphibians. Prey species use chemical signals to modify their morphological development, life history strategy, feeding, and predator avoidance behavior. The advantages of chemical signals are that they can be used in dark or turbid environments by animals that do not have image-forming eyes. Chemical signals are more persistent than mechanical signals, and they allow species-level identification of predator species. In streams, prey species may use mechanical signals (hydrodynamic pressure waves or sound) to avoid predators approaching from downstream (a situation characteristic of streams and in which chemical signals are unreliable) and to initiate escape responses. Predators often depend on chemical signals to stimulate or inhibit feeding, and they use species-specific mecha

The use and abuse of pollinators by fungi - B. A. Roy (Trends in Ecology and Evolution, 1994)
Recent research shows that fungal exploitation of pollinators has the potential to affect floral evolution, pollination ecology, plant life history traits, as well as disease-transmission dynamics and fungal evolution.

Home-range size and exploratory excursions of adult, male yellow-bellied marmots - C. M. Salsbury; Kenneth B. Armitage (Journal of Mammalogy, 1994)
Home-range sizes of adult, male yellow-bellied marmots (Marmota flaviventris) were estimated from radiotelemetry, trapping, and visual observation. Home ranges were monitored from early May to late August in 1989, 1990, and 1991. Home-range size varied greatly among males (range, 0.06–47.51 ha). Median home-range size for all males was 1.02 ha, larger than previous estimates for the species. Distribution of females and localized fluctuations in density of males influenced home-range size of males. Home-range size was not related to number of females defended or to body mass of males. Several males made excursions from their home ranges, perhaps to locate additional mates. These results indicate that male marmots behaviorally respond to the density and distribution of females.

Evolution of Facultative Paedomorphosis in Salamanders - H. H. Whiteman (Quarterly Review of Biology, 1994)
In some salamander species the retention of larval characteristics in sexually mature adults (paedomorphosis) is an alternative to metamorphosis. In many species paedomorphosis is facultative, thus offering a unique opportunity to test predictions on the evolution of life history variation. Here I expand upon a previous hypothesis ("paedomorph advantage") and present two alternative selection mechanisms ("best of a bad lot" and "dimorphic paedomorph" hypotheses) for the maintenance of facultative paedomorphosis. Each hypothesis makes specific predictions regarding the environmental conditions favoring paedomorphosis, the resulting larval growth patterns, and the fitness consequences to each morph. I evaluate each hypothesis by testing these predictions using published data. No study has conclusively determined the relative fitness of paedomorphs and metamorphs, which limits our understanding of the evolution of this polymorphism. Larval growth patterns suggest, however, that both the p

An assessment of the abundance and habitat requirements of the southern red-backed vole, Clethrionomys gapperi on Snodgrass Mountain - A. Benson (1994)

Seasonal movement patterns in a subalpine population of the tiger salamander, Ambystoma tigrinum nebulosum - H. H. Whiteman; S. A. Wissinger; A. Bohonak (Canadian Journal of Zoology, 1994)
Seasonal movements of a subalpine population of metamorphic tiger salamanders, Ambystoma tigrinum nebulosum, were explored from 1990 to 1992. Metamorphic adults bred in permanent and semipermanent habitats during June of each year. After breeding, soma individuals returned to the terrestrial environment, but many remained and congregated in nonpermanent ponds. Metamorphic adults in nonpermanent ponds included those that moved from permanent ponds, those that bred and remained in semipermanent ponds, and those that did not breed but migrated from the terrestrial environment after the breeding season. Dietary analyses indicated that metamorphic adults in nonpermanent ponds have significantly greater numbers, biomass, and calories of prey in their gut than the few metamorphic adults remaining in permanent ponds. This difference was due to the presence of fairy shrimp (Branchinecta coloradensis), which composed 91 % of metamorphic adult diets in nonpermanent ponds and accounted for three t

Diet alters metabolic rate in the yellow-bellied marmot during hibernation. - C. R. Thorp; P. K. Ram; G. L. Florant (Physiological Zoology, 1994)

Patch dynamics of Glaucopsyche lygdamus (Lycaenidae): correlations between butterfly density and host species diversity - D. B. Carey (Oecologia, 1994)

East River water usage problems: effects of current and proposed management practices - J. Renfrow (1994)

Quantitative genetics of sequential life-history and juvenile traits in the partially selfing perennial, Aquilegia caerulea - A. M. Montalvo; R. G. Shaw (Evolution, 1994)
We determined the genetic basis of several traits related to overall fitness of Aquilegia caerulea, a perennial herb of the Rocky Mountains in western North America. To obtain measures of heritability relevant to the evolutionary potential of wild populations, we performed full and partial diallel crosses and studied progeny performance in the field. Based on a joint analysis of two designs with a total of 18 parents and 102 crosses, we detected significant maternal variance for seed mass and emergence time, but this component was negligible for later-expressed traits. Low heritability and evidence that maternal effects on seed mass are largely environmental suggest that in this population there is little evolutionary potential for change in seed mass under conditions experienced during the study. Seed mass varied depending on particular combinations of parents and cross direction. Such an interaction can have several different biological interpretations, including that particular mate

Salamander recruitment in Rockies revisited - J. Harte; E. Hoffman (BioScience, 1994)
Journal Article Salamander Recruitment in Rockies Revisited Get access John Harte, John Harte Energy and Resources Group, University of CaliforniaBerkeley, CA 94720 Search for other works by this author on: Oxford Academic Google Scholar Erika Hoffman Erika Hoffman Energy and Resources Group, University of CaliforniaBerkeley, CA 94720 Search for other works by this author on: Oxford Academic Google Scholar BioScience, Volume 44, Issue 6, June 1994, Page 381, https://doi.org/10.2307/1312358 Published: 01 June 1994

The effect of pocket gopher herbivory on the limitation of aspen outgrowth - J. Yurek (1994)

The Gothic earthflow revisited: a chronosequence examination of colonization on a subalpine earthflow - C. G. Curtin (Vegetatio, 1994)
A chronosequence study of permanent plots spanning 45 years on a 70-year-old subalpine earthflow in south-western Colorado suggests that it is the severe microclimate of the earthflow which is limiting further colonization of the site.

Time-dependent averaging of foraging information in least chipmunks and golden-mantled ground squirrels - L. D. Devenport; L. D. Devenport (Animal Behaviour, 1994)
Behavioural adaptations to resource variability were examined in field experiments with least chipmunks, Tamias minimus, and golden-mantled ground squirrels and were predicted by a dynamic patch assessment model that weights patch information according to its reliability.

Through the 'Scope: An Occurrence of Prehnite in the Red Mountain Mining District Ouray County, Colorado - Tom Rosemeyer (Rocks & Minerals, 1994)

Resting and field metabolic rates of adult male yellow-bellied marmots, Marmota flaviventris - C. M. Salsbury; Kenneth B. Armitage (Comparative Biochemistry and Physiology, 1994)
Total RMR and field metabolic rate of wild-caught males were estimated from oxygen consumption and the doubly-labeled water method and neither total RMR nor specific FMR were significantly related to time.

Follow-up study on success of varying treatment in subalpine road recovery - Philip G. Taylor (1994)

Evolution of alternative life histories in the tiger salamander, Ambystoma tigrinum nebulosum - H. H. Whiteman (1994)

Beyond floral Batemania: sexual selection on pollination success - P. Wilson; J. D. Thomson; M. L. Stanton; L. P. Rigney (American Naturalist, 1994)

The Pending Extinction of the Uncompahgre Fritillary Butterfly - Hugh B. Britten; Peter F. Brussard; Dennis D. Murphy (Conservation Biology, 1994)
Previous mark‐recapture studies and population size estimates indicated that in the 1980s populations of the endangered Uncompahgre fritillary ( Boloria acrocnema ) declined precipitously, apparently leading to extirpation at its type locality. This locality and a nearby second site, both high in the San Juan Mountains of southwestern Colorado, constitute the total known range of B. acrocnema . A survey of 20 presumptive allozyme loci from one B. acrocnema population and seven populations of the closely related B. improba , sampled along the Rocky Mountain cordillera from the Yukon Territory, Canada, to the Wind River Range of Wyoming, revealed that B. acrocnema populations are less variable genetically than are B. improba populations in the northern

Crossing distance effects in Delphinium nelsonii: outbreeding and inbreeding depression in progeny fitness - Nickolas M. Waser; Mary V. Price (Evolution, 1994)

An eye for an eye: can mitigated wetlands pay the bill? - K. Mockler (1994)

Elevational variation of quinolizidine alkaloid contents in a lupine (Lupinus argentus) of the Rocky Mountains - D. B. Carey; M. Wink (Journal of Chemical Ecology, 1994)

Diel feeding and positioning periodicity of a grazing mayfly in a trout stream and a fishless stream - C. A. Cowan; B. L. Peckarsky (Canadian Journal of Fisheries and Aquatic Science, 1994)
We studied the feeding and positioning periodicity on natural substrates of the overwintering and fast-growing summer generations of a grazing mayfly, Baetis bicaudatus, in a third-order trout stream and a fishless, first-order tributary in western Colorado. At 4-h intervals over 24-h, we recorded the number of Baetis on stone tops in flow-through enclosures in situ and in streamside circular flow-through chambers. We determined the feeding periodicity of Baetis using abundance of plant pigments as an index of gut fullness. Baetis were nocturnal in the trout stream; more animals were found on stone tops and guts were fuller at night, suggesting that individuals came to stone tops to feed during darkness. However, Baetis from the fishless stream were either aperiodic or weakly nocturnal. We tested the hypothesis that nocturnal feeding by Baetis is a response to the presence of visually feeding trout by conducting transplant experiments in the circular streams. After 24 h, Baetis transfe

Temperate region interactions between ants and Penstemon strictus - J. Pasewalk (1994)

When do hummingbirds use torpor in nature? - W. A. Calder (Physiological Zoology, 1994)
The physiology of torpor in hummingbirds is well known from laboratory studies, but we still do not know when or how often this means of energy conservation is used in nature, whether regularly (the "routine" hypothesis) or only in response to inadequate food intake (the "emergency-only" hypothesis). I used body masses of broad-tailed hummingbirds (Selasphorus platycercus) to evaluate these hypotheses. Wild birds were weighed on electronic balances (1) on capture in mist-nets or traps and (2) when perched at feeders containing sucrose solutions. Masses followed predictable patterns within a season (breeding or wintering). Estimated energy equivalents of daily cycles of storage and depletion did not support the routine hypothesis. Converted to energy equivalent after adjusting for water content of dusk feeding, the estimated energy equivalent of overnight mass decrease (adjusted for water content of dusk feeding) averaged 15 times the demand for torpor during the breeding season, normal

You can't go home again: effects of an avalanche barrier on small rodent homing - K. Mockler (1994)

Recommendation for the restoration of the East River bridge site, Gothic, Colorado - D. Morris (1994)

Consequences and plasticity of the specialized predatory behavior of stream-dwelling stonefly larvae - B. L. Peckarsky; C. A. Cowan; Craig R. Anderson (Ecology, 1994)
The purpose of this study was to determine experimentally the potential mechanism(s) favoring specialized foraging behavior of stream—dwelling predatory stonefly larvae (Megarcys signata), and whether this specialized behavior was fixed or flexible. We measured stonefly growth rates after 10 d of conditioning on Baetis bicaudatus (Ephemeroptera) or one of two alternative mayfly prey species in replicated circular plexiglass flow—through chambers powered by water from a stream in western Colorado. We then compared attacks per encounter (as an index of predator choice) of conditioned stoneflies to those of unconditioned controls given equal densities of all three prey types. We conducted additional behavioral observations to determine whether predators differentially encountered the alternative prey types on natural substrates, and to determine whether predator—prey microhabitat overlap was mechanism explaining differential prey encounter rates among prey species. Megarcys exhibited a st

Festuca thurberi and Vicia americana - a mutualism? - J. Ruvinsky (1994)

Interspecific and intraspecific interactions of two coexisting montane ground squirrel species (Spermophilus lateralis and Tamias minimus) - M. Arellano (1994)

Beyond floral Batemania: sexual selection on pollination success - P. Wilson; J. D. Thomson; L. P. Rigney; M. L. Stanton; P. Wilson; J. D. Thomson (American Naturalist, 1994)

Systematic increase in pollen carryover and its consequences for geitonogamy in plant populations - William Morris; Mary V. Price; Nickolas M. Waser; B. Thomson; B. Thomson; D. A. Stratton (Oikos, 1994)
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

Secondary Lead-Copper-Zinc Minerals from: The Titusville Mine: San Juan County, Colorado - Tom Rosemeyer (Rocks & Minerals, 1994)

Genetic variation in Penstemon strictus: effects of island habitats - J. Pasewalk (1994)

Everyday is restoration day - E. MacDonald (1994)

An investigation of the structure and location of escape burrows for the ground squirrel Tamias minimus - D. E. Carter (1994)

Biodiversity of aspen (Populus tremuloides) groves: a precursor to studies of ecosystem services - E. L. Catanese; J. B. Hughes (1994)

Mining for bats: a study of the mine usage of bats at the Avery Mine - P. D. Mariner (1994)

Bug It: Factoring in Insect Fauna in Ecological Restoration - R. Carnevale (1994)

Foraging site preferences of rufous and broad-tailed hummingbirds - K. Norton (1994)

A comparison of several lake eutrophication restorative techniques - A. Prussian (1994)

The effect of inflorescence number on bee behavior in Delphinium barbeyi - J. Ruvinsky (1994)

The generation of nuclear waste: are there alternatives? - S. Southard (1994)

Social behavior of ants in the genus Myrmica: occurrence of worker specialization and survivorship implications - A. C. Valdez (1994)

Niche separation in the foraging of tree swallows (Tachycineta bicolor) and violet-green swallows (Tachycineta thalassina) - P. Wright (1994)

Inbreeding depression and maternal effects on Aquilegia caerulea, a partially selfing plant - A. M. Montalvo (Ecology, 1994)

The effects of cattle grazing intensity on riparian environments - M. Pollack (1994)

Evolution of alternative life histories in tiger salamanders (Ambystoma tigrinum nebulosum): a study of the cannibal morph - T. Sacco (1994)

Reintroduction of endangered species - A. Wojtalik (1994)

Exotic plant species along Gothic roadsides - R. E. Collins (1994)

Uncompahgre Fritillary Butterfly Demographics: Response to Britten et al. - A. Seidl; Paul A. Opler (Conservation Biology, 1994)
Using the same methods as Britten, my associates and I ran Pollard transects during four flight seasons at Redcloud Peak and during three flight seasons (1991-93) at Mt. Uncompahgre and found that the populations are declining precipitously, genetic analyses show low heterozygosity, and no heroic effects should be made to salvage the species.

Evaluation of and alternatives to current vegetation management practices of the Crested Butte Mountain Resort - J. Sims (1994)

Toadal Recovery - B. Kelly (1994)

Contributions of Harry Gunnison Brown (1880–1975) - Christopher K. Ryan (Journal of Public Finance and Public Choice, 1994)
Sebbene le opere di Harry Gunnison Brown, prese singolarmente, non siano state trascurate in modo particolare, l’insieme della sua produzione scientifica non è ancora stato oggetto di attento esame. Dopo aver collaborate con Irving Fisher al suo volume sul potere d’acquisto della moneta, Brown pubblicò nel 1914 un libro sul commercio internazionale, nel quale sostenne con vigore il libero scambio. È del 1916 un’importante opera sui criteri per stabilire le tariffe nei trasporti, da lui ricavati basandosi sui loro effetti sul benessere generale. La sua opera più nota è il volume The Economics of Taxation, del 1924, ormai considerate un classico sull’argomento. Un breve scritto del 1939, dedicato all’incidenza di un’imposta generale sulle vendite, ha avuto molto successo a motivo deU’originalità della sua tesi, secondo cui quest’imposta non darebbe luogo ad una diminuzione della produzione e quindi non farebbe aumentare i prezzi. A proposito della Grande Depressione, egli ritenne che una

A tourist profile for the Crested Butte/Gothic area - J. Sims; E. Odell (1994)

Equality found among ant protectors of Helianthella quinquenervis - S. Southard (1994)

Diapause and the host plant affiliations of lycaenid butterflies - D. B. Carey (Oikos, 1994)
Results of three years of study on the host plant affiliations of two lycaenid butterfly species (Lycaenidae) suggest that differences between the two butterflies in host plant range, plant tissue oviposited on by adults and consumed by larvae, larval growth rates, and adult flight season may be consequences of a difference in diapause stage: one species diapauses as a pupa; the other as a larva. The experimental results and logic leading to this conclusion are summarized. The generality of the correlation between diapause stage and host plant relations are tested through a survey of North American and British lycaenids. Significant relatonships are found. Egg-diapausing species tend to utilize woody hosts and be univoltine. Host range is intermediate. Larval-diapausing species utilize leaves of herbaceous plants and have narrow host ranges

Relationships between atmospheric circulation and snowpack in the Gunnison River basin, Colorado - Gregory J. McCabe (Journal of Hydrology, 1994)

Categorization of food types enhances foraging performance of bumble bees - R. Dukas; Nickolas M. Waser (Animal Behaviour, 1994)

Fly pollination of Linum lewisii (Linaceae) - C. A. Kearns; David W. Inouye (American Journal of Botany, 1994)

Oviposition behavior of the white cabbage butterfly, Pieris napi, on native and exotic crucifers - K. N. White (1994)

Time and wariness in yellow-bellied marmots - Kenneth B. Armitage; M. C. Corona (Ibex J.M.E., 1994)

Indirect selection of stigma position in Ipomopsis aggregata via a genetically correlated trait - Diane R. Campbell; Nickolas M. Waser; Mary V. Price (Evolution, 1994)

Pollen viability, vigor, and competitive ability in Erythronium grandiflorum (Liliaceae) - B. A. Thomson; L. P. Rigney; K. M. Karoly; B. A. Thomson (American Journal of Botany, 1994)

Reproductive success of colonial and noncolonial female yellow-bellied marmots - D. H. Van Vuren; Kenneth B. Armitage (Journal of Mammalogy, 1994)

Allozymes in evolutionary genetics: self-imposed burden or extraordinary tool? - W. B. Watt (Genetics, 1994)

Actual Problems of Marmots [sic] Investigation - Kenneth B. Armitage; G. E. Gurri-Glass; Kenneth B. Armitage (1994)

Mineralogy of a Calc-Silicate Locality near: Genesee Park, Jefferson County, Colorado - Daniel E. Kile; Peter J. Modreski (Rocks & Minerals, 1994)

The influence of edge effects on aquatic invertebrate diversity in the streams of the East River Valley of Colorado - J. Baldwin (1994)

The foraging behavior of Ochotona princeps (pika) and how tis correlates to certain aspects of the central foraging theory - J. E. Keet (1994)

Variability of quinolizidine alkaloid profiles of Lupinus argenteus (Fabaceae) from North America - M. Wink; D. B. Carey (Biochemical Systematics and Ecology, 1994)

Queen-queen interactions in the ant species Formica neorufibarbis - J. Bejarano (1994)

Missed opportunity cost for foraging in Tamias minimus, the least chipmunk, and Spermophilus lateralus, the golden-mantled ground squirrel - R. E. Collins (1994)

Actual Problems of Marmots [sic] Investigation - Kenneth B. Armitage (1994)

Does predation effect abundance and diversity of zooplankton in beaver ponds? - E. L. Brookman (1994)

An intra- and inter-species investigation of burrow distances between Spermophilus lateralis and Tamias minimus - D. E. Carter (1994)