The quantification of stream drift - E. Russek; J. D. Allan (Canadian Journal of Fisheries and Aquatic Science, 1985)
Although the purpose of many drift studies is to describe quantitatively the abundance of drifting invertebrates and make comparisons between seasons or sites, almost no investigations have employed replicate sampling. We analyzed drift collections from a Rocky Mountain stream in order to investigate the variability of drift sampling. The data were normalized and the variances stabilized for each taxon examined by data transformation. The fourth root transformation was favored for five taxa and the logarithmic transformation for three. Using the 95% confidence limits on 24-h drift density for an abundant mayfly (Baetis bicaudatus), we found that six to seven replicates are required to obtain 95% CL ± 50% of the mean. Drift sampling appears to require fewer replicates than benthic sampling for comparable precision. Investigators may fail to replicate drift samples because they elect to sample frequently over 24 h in order to quantify the diel periodicity of drift. However, when comparis

Thermal ecology of Pieris butterflies (Lepidoptera; Pieridae): a new mechanism of behavioral thermoregulation - J. G. Kingsolver (Oecologia, 1985)
Results show that Pieris require thoracic temperature in order to take off and fly, and achieve these elevated temperatures by basking, and suggest that a re-evaluation of the functional significance of melanization in Pieris is needed.

Invertebrate predator-prey interactions and stream community structure - S. Walde (1985)

A key to the aquatic insects of streams in the vicinity of the Rocky Mountain Biological Lab, including chironomid larvae from streams and ponds - D. J. Conklin; S. I. Dodson; B. L. Peckarsky (1985)

Duration of female availability and its effect on butterfly mating systems - F. J. Odendaal; Y. Iwasa; P. R. Ehrlich (American Naturalist, 1985)
A major link between larval ecology and mating systems in butterflies is the environment in which larvae hatch. It determines when a female should lay her eggs, and therefore when she will be receptive to mating. The fitness of males is determined chiefly by access to fertilizable females, and therefore is greatly affected by the reproductive schedules of females. We show how female availability may influence and interact with many aspects of butterfly mating systems.

Airborne pollen and mold spores in a subalpine environment - E. Leventin; P. Buck (Annals of Allergy, 1985)

Acid precipitation and surface-water vulnerability on the western slope of the high Colorado Rockies - H. Michaels; C. J. Blanchard; G. P. Lockett; R. A. Schneider; John Harte (Water, Air, and Soil Pollution, 1985)

Fine structure of the mucocysts of Colacium calvum (Euglenophyceae) - R. L. Willey (Journal of Phycology, 1984)
ABSTRACTThe characteristic stalk of Colacium calvum Stein is formed from carbohydrate extruded by granules in the anterior portion of the cell. These granules exhibit the characteristics of mucocysts and their contents have two electron densities. A narrow extension of each granule extends past neighboring muciferous bodies to attachment sites in the posterior notch of the pellicle strip. The granule contains neutral polysaccharide which resembles that in the peripheral cisternae of the Golgi apparatus. The attachment site is structurally complex.

Experimental studies of pollen carryover: effects of floral variability in Ipomopsis aggregata - Mary V. Price; Nickolas M. Waser (Oecologia, 1984)
It was found that the slopes of linear dye carryover functions generally became more shallow as floral variability increased; this led to substantially longer carryover in the treatment with greatest variability, and total amounts of dye transferred did not appear to be sensitive to the degree of variability.

Stream Ecology: Application and Testing of General Ecological Theory - B. L. Peckarsky (1984)

A test of the river continuum concept (1984)

An alpine test of the river continuum concept - S. E. Travers (1984)

Foraging patterns of yellow-bellied marmots: role of kinship and individual variability - B. A. Frase; Kenneth B. Armitage (Behavioral Ecology, 1984)

Growth rate respnse to intraspecific and interspecific competition in two alpine annuals - S. E. Travers (1984)

Plasma melatonin concentrations in hibernating marmots: absence of a plasma melatonin rhythm - M. L. Rivera; L. Tamarkind; A. K. Lawrence; G. L. Florant (American Journal of Physiology, 1984)
Plasma melatonin concentrations were measured throughout bouts of hibernation in marmots maintained in a short photoperiod (light-dark 8:16) and ambient temperature of 5 or 15 degrees C. Melatonin concentration was also measured in two animals maintained in constant darkness. As an animal entered hibernation, plasma melatonin concentrations dropped to basal levels when body temperature reached 25 degrees C, and they remained low until arousal. During deep hibernation plasma melatonin values did not vary significantly (P greater than 0.05) with respect to time of day or different ambient temperatures. With nocturnal arousal plasma melatonin levels were similar to euthermic night values. Lack of a plasma melatonin rhythm during hibernation suggests that the pineal gland is not temperature compensated during hibernation, and due to the low tissue temperature of the pineal the circadian pacemaker driving melatonin secretion is incapable of stimulating a rhythm.

Colias alexandra: a model for the study of natural populations of butterflies - J. L. Hayes (Journal of Research on the Lepidoptera, 1984)

A survey of insect herbivores on five species of willow (Salix) with regard to competition - C. Sturges; J. Trevio; L. B. Zimmerman; S. Reed; N. Patel; T. L. Morton; S. Kaiser; S. E. Travers (1984)

Tolerance of Ambystoma tigrinum larvae to spring water from a mining area; or, "the canary in the mind - L. B. Zimmerman (1984)

Some observations on spatial distribution in a montane population of Euphydryas editha - D. R. Wheye; P. R. Ehrlich (Journal of Research on the Lepidoptera, 1984)
Counts of montane Euphydryas editha along transects at Almont Summit, Colorado, show that males form a dense aggregation along a ridgetop with an estimated 30:1 (male:female) sex ratio. Fertilized females showed preference for subsites below the ridgetop at least as rich in oviposition plants but less rich in nectar resources, where the sex ratio was close to 1:1. Mark-release-recapture data suggest mating is less probable on the ridgetop than below it. This suggests the possibility that nonaggregating males, at least under conditions similar to those of 1983, may have greater reproductive success than those in aggregations, raising questions about the function of such aggregations.

Pollen shortcomings - Nickolas M. Waser (Natural History, 1984)

A Proterozoic Volcano-Plutonic Terrane, Gunnison and Salida Areas, Colorado - M. E. Bickford; S. J. Boardman (The Journal of Geology, 1984)
Early Proterozoic supracrustal rocks near Gunnison and Salida, Colorado include tholeiitic basalt, dacite to rhyolite, and intercalated sedimentary rocks. These were intruded by essentially synchronous gabbroic sheets, folded, and intruded by major plutons ranging from quartz diorite to granite. Preservation of primary volcanic and sedimentary features is good to excellent; sedimentary rocks in the Gunnison area are mostly turbidite wackes whereas near Salida they are mostly near-source volcaniclastic rocks. U-Pb age measurements on zircons indicate that the earliest bimodal volcanic rocks erupted between 1770 and 1760 m.y. ago and were intruded by granitic plutons between 1760 and 1750 m.y. ago. Renewed bimodal volcanism occurred between 1740 and 1730 m.y. ago and was followed by a period of deformation producing two fold sets before 1725 m.y. ago when the first of a series of younger plutons was emplaced. The compositions and features of the sedimentary rocks and their association wi

A survey of herbivorous insect species along a phylogenetic gradient - K. S. Brooks; P. Valiulis; D. Sims; J. McAndrews (1984)

The life history and ecology of Euphydryas gillettii Barnes (Nymphalidae) - E. H. Williams; C. E. Holdren; P. R. Ehrlich (Journal of the Lepidopterists' Society, 1984)

The Ecology of Aquatic Insects - J. D. Allan (1984)

Initial inventory of plant on 1977 Avery Peak debris flow - P. J. Lehr (1984)

Evidence for the existence of a mutualistic relationship between Helianthella quinquenervis and ants - D. Sims; J. Trevio; K. S. Brooks; J. McAndrews; S. E. Travers (1984)

Seed set in Erythronium grandiflorum pollen color morphs - D. Sims (1984)

Proximal Causes of Dispersal in Yellow-bellied Marmots - Alison K. Brody (1984)

A test of the river continuum concept - S. Kaiser; M. M. Reed; D. Sims (1984)

The ant and the sunflower - David W. Inouye (Natural History, 1984)

Size, Function and Life History - W. A. Calder (1984)

Ecology of Aquatic Insects - B. L. Peckarsky (1984)

The optimal sugar concentraion for hummingbirds - dependence on energy intake rates - K. S. Brooks (1984)

A study of the effects of parasitism on aphid populations - S. Kaiser (1984)

Interactions of two species of the family Fringillidae, the Cassin's finch (Carpodacus cassinii) and the pine siskin (Spinus pinus) - J. Trevio (1984)

The river continuum concept - Class; J. Trevio (1984)

Alpine aberrations in the river continuum concept - L. B. Zimmerman (1984)

Phenology of glucosinolate concentrations in roots, stems and leaves of Cardamine cordifola - J. E. Rodman; S. M. Louda (Biochemical Systematics and Ecology, 1984)

Feeding choice experiments with Peromyscus maniculatus on 5 species of butterflies - P. Valiulis (1984)

Test of the river continuum concept - P. Valiulis (1984)

Organization of a plant-pollinator community in a seasonal environment - Lesleigh Anderson (1984)

Larval Colorado Squawfish (Ptychochielus lucius Girard) in the Upper Colorado River Basin, Colorado, 1979-1981 - R. T. Muth; E. J. Wick; T. A. Lytle; C. M. Haynes (The Southwestern Naturalist, 1984)
C. M. Haynes, T. A. Lytle, E. J. Wick, R. T. Muth, Larval Colorado Squawfish (Ptychochielus lucius Girard) in the Upper Colorado River Basin, Colorado, 1979-1981, The Southwestern Naturalist, Vol. 29, No. 1 (Mar. 23, 1984), pp. 21-33

Spatial relationships and social organization in adult pikas: a facultatively monogamous mammal - B. L. Ivins; Arthur E. Smith (Zeitschrift fr Tierpsychologie, 1984)
Abstract and SummaryAdult spatial relationships and social organization in a marked population of alpine mammals, the pika (Ochotona princeps), were studied over a 3‐year period in the Rocky Mountains of Colorado. Home range size, distances between centers of activity of dyads, and weighted overlaps of home ranges of dyads were used to define space use patterns. Disappearance and establishment of individuals reflected the temporal component of space use. Relative frequencies of foraging (haying and feeding), surveillance, and communication (short calling, long calling, cheek rubbing) behaviors were recorded. Social relationships among adults were defined by agonistic interactions (aggression) and affiliative behaviors (social tolerance, vocal duets, copulations).Males and females occupied individual home ranges of equal size on talus, their obligate habitat type. Adjacent home ranges were normally occupied by pikas of the opposite sex. Replacement of home ranges was always by a member

The size composition of invertebrate drift in a Rocky Mountain stream - J. D. Allan (Oikos, 1984)
Drift collections from a Rocky Mountain stream were used to examine the hypothesis that, because risk of predation by fish is greatest for large individuals during the day, aquatic insects should become increasingly nocturnal in their drift periodicity as they grow in size. Seven taxa common in the drift were analyzed by one of two approaches. Where data were extensive, a nocturnal activity index was obtained by dividing night drift density by day drift density for a number of size classes. This index showed a significant positive association with size (mean dry wt) for the two mayflies tested, Baetis bicaudatus and Cinygmula sp. The largest size classes often were exclusively nocturnal in their drift activity. For less common taxa I simply compared the size composition during the night with that during the day for each date with sufficient data. In the mayfly Drunella coloradensis, the stonefly Zapada haysi and Chironomidae, large individuals were more frequent in night than day colle

Influence of host plant height and distribution on herbivory patterns - J. McAndrews (1984)

Short-term learning and the searching accuracy of egg-laying butterflies - M. L. Stanton (Animal Behaviour, 1984)
Two interpretations are presented: (1) that partitioning searching time into discrete modes may enhance overaccuracy in invertebrates, as has been demonstrated previously for vertebrates and (2) that search dynamics of this type may explain some discrepancies between the predictions made by simple optimal diet models and the occurrence of ‘switching’ behaviours in foragers.

The relationship between flowering phenology and seed set in an herbaceous perennial plant, Polymonium foliosissimum Gray - R. S. Gross; Marian A. Zimmerman (American Midland Naturalist, 1984)
To assess the potential for evolutionary change in blooming time within a population of Polemonium foliosissimum Gray (Polemoniaceae), flowering phenology, seed set and seed predation frequencies of individual plants were monitored from 1977-1981 in the Colorado Rocky Mountains. In only 1 of 4 years was there a significant correlation between flowering rank and average seed set per flower. In contrast, there was a significant (or nearly significant, p<.06) positive correlation between blooming time and total plant seed set in 3 of 4 years. These positive correlations resulted from greater flower production by later-blooming plants. Thus, total seed set varied independently of seed production on a per blossom basis, indicating that seed set per flower'should be used only with caution as a measure of the maternal component of plant fitness. The fairly consistent positive relationship between blooming time and totat seed set indicates that directional selection for later flowering may be

Migration and population dynamics of hummingbirds - W. A. Calder (National Geographic Society Research Reports, 1984)

The effects of capturing and marking on subsequent activity in Boloria acrocnema (Lepidoptera: Nymphalidae), with a comparison of different numerical models that estimate population size - L. F. Gall (Biological Conservation, 1984)

Mechanistic constraints and optimality models: thermoregulatory strategies in Colias butterflies - J. G. Kingsolver; W. B. Watt (Ecology, 1984)
To explore mechanistic constraints on the evolution of optimal phenotypes, we develop an optimality model for thermoregulation in Colias butterflies. The model identifies the thermoregulatory characteristics of butterflies that maximize time available for flight activity subject to an overheating constraint, and was tested in three Colias populations along an elevational gradient. Model simulations and field results showed that environmental variation limits available flight time in higher elevation populations, even for optimally designed butterflies. Optimal predicted thermoregulatory characteristics were within two standard deviations of the observed characteristics in each population. Model simulations and field transplant experiments showed that large departures from optimality would have deleterious consequences for flight and overheating. This represents the first test of a strategy model for optimal thermoregulatory characteristics in animals. Our results illustrate how the con

Oviposition Behavior of Hylemya(Delia)sp. (Diptera:Anthomyiidae): Suboptimal Host Plant Choice? - B. Schulte; D. A. Cibula; Marian A. Zimmerman (Environmental Entomology, 1984)

Plasma melatonin rhythms in euthermic marmots (Marmota flaviventris) - L. Tamarkind; G. L. Florant (Biology of Reproduction, 1984)

Biology of Ground-Dwelling Squirrels: Annual Cycles, Behavioral Ecology, and Sociality - Kenneth B. Armitage (1984)

Post-breeding avifauna and mixed insectivorous flocks in a Colorado spruce-fir forest - J. L. Wagner (Western Birds, 1984)

The deep plunge: a test of the river continuum concept - J. McAndrews (1984)

Reconnaissance geology of the Mississippian Leadville limestone and implications for mineralization controls, Fulford mining district, Eagle County, Colorado - Billy D Richards (K-State Research Exchange (Kansas State University), 1984)
Deserving of much appreciation are Russell K. Murphy, who assisted in navigating the rugged field terrain, and the E. C. Lorig family of Eagle, Colorado, whose friendship, generosity, and guidance were extremely valuable

Herbivore effect on stature, fruiting and leaf dynamics of a native crucifer - S. M. Louda (Ecology, 1984)
The impact of a native, leaf—feeding chrysomelid beetle (Phaedon sp. nr. oviformis) on bittercress (Cardamine cordifolia: Cruciferae), was evaluated in an exclusion experiment. Multivariate statistical analysis showed a significant increase in plant performance in the rotenone exclusion compared to performance in the paired control treatment. Plant response to the reduction of herbivory was a complicated, interrelated syndrome of changes. When insects were excluded, the amount of missing leaf area decreased significantly (3.6—fold; 3.2—0.9 cm2 per plant), and the total leaf area increased 5.7—fold (12.9—73.4 cm2 per plant). Plant height (5.7—20.3 cm) and fruit production (0.1—3.9 siliques per plant) also increased significantly when the number of insects was reduced. Furthermore, the 570% expansion in leaf area due to the exclusion of insects involved signficant increases both in the initiation of new leaves and in the survival of mature leaves. Nevertheless, insect herbivory at a leve

Optimal clutch size in agromyzid fly larvae - C. Sturges; S. Reed; N. Patel; S. Kaiser (1984)

Gregariousness in chrysomelid beetle larvae - P. Valiulis; L. B. Zimmerman; T. L. Morton (1984)

Leave it to the beavers: a study of the effects of natural impoundments on macroinvertebrate community structure - M. M. Reed (1984)

A Manual on Methods for Assessing Secondary Productivity in Freshwaters - B. L. Peckarsky (1984)

Mt. Antero Mineral Locality, Chaffee County, Colorado: Past & Present - Mark Ivan Jacobson (Rocks & Minerals, 1984)
Click to increase image sizeClick to decrease image size Additional informationNotes on contributorsMark Ivan JacobsonMark I. Jacobson, an oil exploration geophysicist, last wrote for ROCKS AND MINERALS on “A Lithium-Bearing Pegmatite in the Clear Creek District, Clear Creek County, Colorado” (November December 1982).

The Rocky Mountain Biological Laboratory - W. H. Emig; B. L. Peckarsky (Bulletin of the North American Benthological Society, 1984)

Hydrology analysis of the Colorado River floods of 1983 - WilliamB. Vandivere; Peter Vorster (GeoJournal, 1984)

Ponderosa pine dwarf mistletoe loss assessment survey on National Forest lands in Colorado - Frank G. Hawksworth; Laura M. Merrill; David W. Johnson; United States. (1984)
During 1981-82, a roadside/plot survey was conducted on National Forest lands in Colorado to estimate annual merchantable cubic-foot volume loss caused by ponderosa pine dwarf mistletoe in ponderosa pine.This survey indicated that 18 percent of the type was infested.The total annual loss of ponderosa pine to dwarf mistletoe is estimated at 885,000 cubic feet.This loss is equivalent to 57 percent of the 1981 annual harvest of ponderosa pine for the Forests surveyed.

Infanticide in yellow-bellied marmots - J. C. Melcher; Alison K. Brody (Animal Behaviour, 1984)

Population structure and recommendations for conservation of the narrowly endemic alpine butterfly Boloria acrocnema (Lepidoptera: Nymphalidae) - L. F. Gall (Biological Conservation, 1984)
Mark-recapture data indicate that daily population sizes are low, most adults remain in residence at the colony only a few days, and there are age-specific sexual differences in movement, with older females perhaps leaving the colony site.

Reproduction in Polymonium: a five year study of seed production and implications for competition for pollinator service - Marian A. Zimmerman (Oikos, 1984)
Conditions necessary for intraspecific competition for pollinator service, but not intraspecific competition itself, have previously been reported for a population of Polemonium foliossisimum Gray. As in most recent work of this sort, this conclusion was based, in part, on seed set differentials among individuals as well as between control and hand-pollinated flowers. Such differentials, when found for a single flowering season in perennial plants can, however, be misleading. Stored reserves might be drawn upon one season at the expense of the reproductive potential of later years negating an apparent reproductive increase. A five year study of seed set and flower production in a P. foliosissimum population indicates that no such reproductive tradeoff is occurring. Available information is consistent with the contention that intraspecific competition for pollinator service may have taken place and thus supports conclusions drawn from short term studies on P. foliosissimum.

The Colorado River: River of Controversy - Robert Coats (Environment: Science and Policy for Sustainable Development, 1984)

Clumping in beetle eggs: are larger clumps better? - T. L. Morton (1984)

A Rocky Mountain Test of the River Continuum Concept - T. L. Morton (1984)

The effect of plant density on departure decisions: testing the marginal value theorem using bumblebees and Delphinium nelsonii - D. A. Cibula; Marian A. Zimmerman (Oikos, 1984)
Bombus flavifrons utiliserait la densite de la plante butinee pour estimer le cout eventuel d'approvisionnement

Hematology of Four Rare Colorado River Fishes - Charles R. Berry (Copeia, 1984)

Plant colonization of talus islands - Kenneth L. Jones (1983)

The ecology and evolution of symbioses between lycaenid butterflies and ants - N. E. Pierce (1983)

Roles of the wing whistle in the territorial behaviour of male broadtailed hummingbirds (Selasphorus platycercus) - S. M. Miller; David W. Inouye (Animal Behaviour, 1983)
Results of this study suggest that the wing whistle of male broad-tailed hummingbirds is important in maintenance of courting territories and hence in reproductive success.

A biogeophysical study of the plant-soil interface in varied habitats - I. R. Hoeppner (1983)

Floral formula inconstancy within and among plants and populations of Ipomopsis aggregata (Polemoniaceae) - N. C. Ellstrand (Botanical Gazette, 1983)
The numbers of flower parts are considered among the most constant angiosperm characters However, nearly 33% of the plants in 13 populations of Ipomopsis aggregata in Colorado had at least one anomalous flower, and almost 10% of the flowers displayed abnormal merism (abnormal floral formulas) Floral inconstancy varied significantly among populations The number of abnormal flowers per plant increased with the proportion of plants displaying abnormal merism at a given site Abnormal flowers were nonrandomly distributed; more plants had multiple anomalous flowers than expected by chance The gynoecium was the most variable flower part and varied independently of the other parts, which tended to vary in a coordinated fashion These observations are compared with other examples of abnormal merism in the Polemoniaceae

Nectar feeding, diuresis, and electrolyte replacement of hummingbirds - S. M. Hiebert; W. A. Calder (Physiological Zoology, 1983)
Hummingbirds depend on floral nectars for energy. This entails a significant water excess which is eliminated in chronic diuresis. In the eight species from which we obtained urine samples, solutes were conserved by reducing urine osmotic concentrations to approximately one-fifth of plasma levels. Sodium and potassium salts accounted for one-half to one-third of the osmotic concentration of urine. These salts can be replaced mostly from trace amounts in the floral nectars. Data from field, laboratory, and the literature are combined to account for salt and water exchanges of broad-tailed and rufous hummingbirds. Published accounts of avian renal morphology and physiology are consistent with hummingbird urinalysis.

Sexual dimorphism in Valeriana edulis Nutt. (Valerianaceae) - G. Dieringer (1983)

Emergence patterns in male butterflies: a hypothesis and a test - A. E. Launer; F. J. Odendaal; Y. Iwasa; Dennis D. Murphy; P. R. Ehrlich (Theoretical Population Biology, 1983)
A game theoretical model is advanced to explain the emergence time schedule of male butterflies under temporal “apostatic” selection, so that males emerging on different days enjoy equal fitness in evolutionary equilibrium.

Sources of intraspecific variation in the hostplant seeking behavior of Colias butterflies - Robert B. Cook; M. L. Stanton (Oecologia, 1983)
Females tended to specialize upon one or two species, at least in the short term, and the pattern of oligophagy for the population as a whole is partly generated by variation in the host-seeking behavior of individual females.

An allometric approach to population cycles of mammals - W. A. Calder (Journal of Theoretical Biology, 1983)
The periodic cycles in populations of microtine rodents and hares are considered together to provide the suggestion that the natural period is endogenous and size-dependent, and may be a consequence of the physiological and reproductive pace of the life cycle that scales as the fourth root of body mass.

Pollinator behaviour and natural selection for flower colour in Delphinium nelsonii - Mary V. Price; Nickolas M. Waser (Nature, 1983)
Evidence is presented that discrimination occurs because white flowers have inferior ‘nectar guides’ and therefore require longer handling times than blue flowers, and pollinators may experience lower net rates of energy intake on white flowers, a sufficient reason for undervisitation by optimally-foraging animals.

Sodium, potassium and chloride in floral nectars: energy-free contributions to refractive index and salt-balance - S. M. Hiebert; W. A. Calder (Ecology, 1983)

Hematological values for free-ranging yellow-bellied marmots - Kenneth B. Armitage (Comparative Biochemistry and Physiology, 1983)
Hematological values of scuirids are adaptive to environmental factors such as hypoxia of burrows and high altitude, temperature and metabolic rate, and PCV of yellow-bellied marmots evidences an adaptive response to high altitude when compared to the closely-related woodchuck, M. monax.

The responses of lake waters to organic matter additions. - D. Levy; John Harte (Hydrobiologia, 1983)

Effects of ant mounds on soil chemistry and vegetation patterns in a montane Colorado meadow - D. C. Culver; A. J. Beattie (Ecology, 1983)

Test Excavations at Site 41CD56 Colorado County, Texas - Glenn T. Goode (Index of Texas Archaeology: Open Access Gray Literature from the Lone Star State, 1983)
Site 41CD56 is an aboriginal site located on Crier Creek in northwestern Colorado County, Texas. Testing in October, 1983, revealed that moderate amounts of thermally altered chert/quartzite and lithic debitage were contained in sandy deposits varying from 20 to 110 cm in depth. Two burned rock accumulations, possibly disturbed hearths, were discovered; but no diagnostic tools or indicators of cultural affiliation were found.

Porosity Dependence of Deformation Bands In The Entrada Sandstone, La Plata County, Colorado - Gary A. Smith (Mountain Geologist, 1983)
Close examination of zones of deformation bands in the Entrada Sandstone (Middle Jurassic) near Durango, Colorado suggests that the width of these vertical zones and the displacement across them is directly related to the porosity of the sandstone. Low porosity sandstone is less susceptible to fracturing than high porosity sandstone because greater energy is required to propagate cracks through quartz grains and calcite cement than through pore space. This observation is considered a field confirmation of the experimental work by Dunn et al. (1973)

Distribution of Corticolous Noncrustose Lichens on Trunks of Rocky Mountain Junipers in Boulder County, Colorado - Janet L. Peard (The Bryologist, 1983)
Nineteen species of noncrustose lichens were found on juniper bark. Of these, three species had relatively high cover and frequency values and were characterized as typical lichens of Rocky Mountain junipers: Xanthoria fallax, Phaeophyscia hirsuta and Physcia caesia. Total cover per tree was low (4%), and most species preferred the north and east sides of trunk bases. These distributional trends may reflect gradients of exposure to wind, insolation, and rate of bark exfo- liation. The trunk of a tree provides a wide spectrum of microhabitats for epiphytic vegetation. The physical and biotic factors that interact to create these environments have been dis- cussed in great detail by Barkman (1958). Horizontal and vertical gradients of light, water, and temperature depend upon direction of trunk exposure and height above ground. Bark hardness, texture, water-holding capacity, and acidity vary among tree species and within species according to age of the bark. In the Front Range area of Co

Vegetational diversity and succession of mine tailing slopes and natural earthflow areas: a comparison (1983)

Nectar production patterns in Ipomopsis aggregata (Polemoniaceae) - J. L. Pleasants (American Journal of Botany, 1983)
This study describes nectar production patterns for Ipomopsis aggregata and discusses their potential adaptive and ecological significance. It also examines the influence of environmental and other factors on nectar production rate (NPR) and nectar sugar concentration. For I. aggregata there were no NPR differences with flower age. An hypothesis for the presence or absence of such differences is discussed. Ipomopsis aggregata has a relatively constant rate of nectar production during the day and production continues overnight but at a reduced rate. Newly opened flowers already have a sizeable accumulation of nectar. 24‐hr nectar sugar production on overcast days was 62% of sunny day production. NPR values at the beginning of the flowering season were almost twice as great as those near the end but the sugar concentration did not change. Whether nectar was removed periodically (to simulate pollinator visits) or simply allowed to accumulate over 24 hr had no effect on total production. N

The distribution of standing crop of nectar: what does it really tell us? - J. L. Pleasants; Marian A. Zimmerman (Oecologia, 1983)
Brink (1982) characterizes the distribution of standing crop of nectar for Delphinium nelsonii as bonanzablank, based on comparison with a Poisson, but this work disagrees with the use of the Poisson and the resulting conclusions.

Flowering plant density and pollinator visitation in Senecio - J. Schmitt (Oecologia, 1983)
In Senecio, flowering phenology patterns and differences among pollinators in foraging behavior may have more important consequences for seed set and gene flow patterns than plant density or plant size.

Petrogenesis of the A.O. Porphyry Copper Complex in Jackson and Grand Counties, Northwestern Colorado - W. W. Jr. Atkinson; M. H. Karimpour (Global Tectonics and Metallogeny, 1983)

Adaptation at specific loci. II. Demographic and biochemical elements in the maintenance of the Colias PGI polymorphism - W. B. Watt (Genetics, 1983)
ABSTRACT Demographically oriented sampling in the wild and biochemical study of allozymes in the laboratory have been used to probe maintenance of the phosphoglucose isomerase polymorphism of Colias butterflies.—The several alleles at this locus show negative or no covariation among their frequencies in the wild. This rules out Wahlund effects as a cause of observations of heterozygote excess at this locus in broods that fly as single cohorts. Unusually heavy mortality among adults, due to drought stress or other causes, can preclude manifestation of differential survivorship among phosphoglucose isomerase genotypes. In broods composed of overlapping cohorts, heterozygote deficiency, apparently due to Wahlund effects in time as cohorts of different survivorship experience mix, can be found. Heterozygotes at this locus fly under a broader range of weather conditions than other genotypes.—Previously detected kinetic differentiation among the genotypes extends in greater ma

Site-fidelity, longevity, and population dynamics of broadtailed hummingbirds: a ten-year study - S. M. Miller; S. M. Hiebert; W. A. Calder; Nickolas M. Waser; David W. Inouye (Oecologia, 1983)

The coevolution of Euphydryas chalcedona butterflies and their larval host plants. II. Maternal and host plant effects on larval growth, development, and food-use efficiency - D. E. Lincoln; P. R. Ehrlich; Kenneth Hurst Williams (Oecologia, 1983)

Thermoregulatory strategies in Colias butterflies: thermal stress and the limits to adaptation in temporally varying environments - J. G. Kingsolver; W. B. Watt (American Naturalist, 1983)
As a case study of adaptive strategies in temporally varying environments, thermoregulation in three populations of Colias butterflies along an elevation gradient in Colorado is studied in relation to the fluctuating meteorological environment. Emphasis is placed on short time scale (15-300 s) variation in air temperature and wind speed and its role in determining elevational patterns of body temperature, flight activity, and thermal stress due to overheating. A stochastic, linear filter model of an organism in a variable environment is used which views the adaptive process as the adjustment of the organism's filter. The relation-ship between this filter model and a transient energy balance model of the butterfly is examined to show how the thermoregulatory mechanisms of adaptation determine the filtering properties of the organism. Heat shocks at 45⚬ C significantly decrease survivorship and fecundity in Colias. Time series analysis indicates that short-term variation in wind speed an

Density effects in the plant-animal interactions of Potentilla gracilis douglas (Roseaceae) - S. G. Vail (1983)

Ecological significance of flight activity in Colias butterflies: implication for reproductive strategy and population structure - J. G. Kingsolver (Ecology, 1983)
The observed differences in catchability between sexes is also correlated with the sexual differences in flight behavior reported here, and the time spent in flight, short life expectancies, and time budgets of Colias suggest that the time available for flight activity during an individual's lifetime may be limited.

Bumblebee foraging patterns on Frasera speciosa inflorescences or, a monumental approach to Gothic queens - A. Head (1983)

Distribution of Mertensia fusiformis - Cynthia S. Jones (1983)

Handbook of Experimental Pollination Biology (1983)

A comparison of the effects of predispersal seed predation on seed set of three Rocky Mountain plant species in the sun and shade - S. Wetmore (1983)

Reproductive tactics of pikas: why have two litters? - B. L. Ivins; Arthur E. Smith (Canadian Journal of Zoology, 1983)
Reproduction in a population of marked pikas (Ochotonaprinceps) was observed over a 3-year period in the Rocky Mountains of Colorado. Pikas were seasonally polyestrous; all adult females initiated two litters each summer. However, most females (24 of 25) weaned only a single litter. The number of successfully weaned litters and offspring was divided evenly between first and second breeding attempts. Previous studies had noted that less than 10% of juveniles emerged from second litters. Apparently females are capable of weaning second litters, but only if first litters are lost. Loss of first litters may result from nest predation or poor maternal condition caused by extreme winters. Reproductive constraints acting on pikas and their evolved reproductive tactics are compared with those of other alpine or boreal long-lived herbivorous small mammals.

The "white male" variant of Colias (Pieridae): two new records from Colorado - L. F. Gall (Journal of the Lepidopterists' Society, 1983)

Handbook of Experimental Pollination Biology - J. L. Pleasants; Mary V. Price; Nickolas M. Waser; Nickolas M. Waser (1983)

Calculating nectar production rates: residual nectar and optimal foraging - Marian A. Zimmerman (Oecologia, 1983)
The fact that residual nectar exists is consistent with predictions of optimal foraging theory but more detailed work is necessary before it can be concluded that the volumes left behind in A. columbianum flowers are optimal.

Nectar dispersion and bumblebee foraging in Delphinium nelsonii - B. Eiseman; A. Head; M. Duff; J. D. Gerut; A. S. Daggett; Cynthia S. Jones; Kenneth L. Jones (1983)

Dandelion build-up around buildings in Gothic - J. D. Gerut (1983)

Interspecific competition in Rocky Mountain meadow flora - M. Duff; A. Head; J. D. Gerut (1983)

Review: A River No More: The Colorado River and the West, by Philip L. Fradkin - Abraham Hoffman (Pacific Historical Review, 1983)

Resource assessment for Region 4, Colorado Plateau : Little Book Cliffs/Wildhorse area / - Wallaby Enterprises.; Mountain States Mineral Enterprises.; United States. (1983)
The WSA has low favorability for locatable minerals.

Testing the river continuum concept - M. Driff; B. Eiseman; A. S. Daggett; Cynthia S. Jones; A. Head; J. D. Gerut; Kenneth L. Jones (1983)

The pollination ecology of Aquilegia micrantha (Ranunculaceae) in Colorado - Robert R. Miller; C. L. Willard (Southwestern Naturalist, 1983)
Aquilegia micrantha occurs in canyons of the Southwestern United States. The pinkish-yellow flowers are nodding or semi-nodding, mildly scented, protandrous, and secrete a concentrated nectar (46% total sugars). Seed set in flowers under pollinator exclosures was 25% compared with 63% for open-pollinated flowers. The most common and effective pollinators of A. micrantha in the upper Crystal River Canyon were nectar-foraging bumblebee queens, Bombus appositus and B. flavifrons, although hummingbirds and hawkmoths also visited the flowers, and hummingbirds are important pollinators at other sites. The absence of nectar-foraging Bombus queens on the red flowers of A. elegantula in the area is probably the result of the narrower spur mouths of A. elegantula that prevent the bees from inserting their heads deeply enough into the flowers to extract the nectar. This mechanical isolaiton may be important in restricting hybridiza- tion between the two species in the narrow elevational range of

Geology and mineral resource potential of the Black Ridge Canyon wilderness study area, Mesa County, Colorado : (GEM phase 2) / - Margo I. Toth; Geological Survey (U.S.) (1983)
Rock samples from the WSA were also low in elements associated with mineralized systems.

Responses of pikas (Ochotona princeps, Lagomorpha) to naturally occurring terrestrial predators - B. L. Ivins; Arthur E. Smith (Behavioral Ecology, 1983)
Weasels were determined to be more effective predators of pikas than martens, and these asymmetries in behavior and alarm vocalizations may indicate that responses reduce an individual's risk of predaton by weasels.

Ecological scaling: mammals and birds - W. A. Calder (Annual Review of Ecology and Systematics, 1983)
The effort necessary to measure the differences in lifetime reproductive success in nature has already been described convincingly (20). All impregnations, births, and deaths that occur throughout the entire turnover of a wild population must be recorded. This process is both necessary and fascinating, but it is slow. The individual recognition and continuous surveillance necessary to accom plish this task are difficult, if not impossible, to attain with small animals; they require extremely long projects for large, conspicuous, and long-lived ones. In the interim, as our species is rivet-popping on Spaceship earth (27), we need to have a general pattern that we can use for comparative and predictive purposes (25). Has each life history evolved uniquely with random details that must all be described de novo, or is there a ground plan with design constants for an entire class or other major taxon (32, 60)? Body size is the predominant influence on an animal's requirements and opportuni

Study of population structures in Rocky Mountain Butterflies - B. Eiseman; A. Head; M. Duff; A. S. Daggett; J. D. Gerut; Cynthia S. Jones; Kenneth L. Jones (1983)

Ecological patterns in glucosinolate content of a native mustard, Cardamine cordifolia, in the Rocky Mountains - J. E. Rodman; S. M. Louda (Journal of Chemical Ecology, 1983)

Resource assessment for Region 4, Colorado Plateau : West Cold Springs - Diamond Breaks area GRA 1 / - Mountain States Mineral Enterprises.; Wallaby Enterprises.; United States. (1983)

Resource assessment for Region 4, Colorado Plateau : McKenna Peak area GRA 9 / - Wallaby Enterprises.; Mountain States Mineral Enterprises.; United States. (1983)
The BLM has adopted a two-phase procedure for the integration of geological, energy and minerals (GEM) resources data for suitable/nonsuitable decisions for wilderness study areas (WSA's).

Problems in the use of genetic similarity to show relatedness - O. A. Schwartz; Kenneth B. Armitage (Evolution, 1983)

Hadrosaur Locomotion and Herding Behavior: Evidence from Footprints in The Mesaverde Formation, Grand Mesa Coal Field, Colorado - Bennett H. Young; Martin G. Lockley; Kenneth Carpenter (Mountain Geologist, 1983)
Dinosaur footprint casts from a Mesaverde (Campanian) coal mine near Gunnison, Colorado resemble those of the notorious "mystery dinosaur, Xosaurus" which was probably a giant hadrosaur. Existing footprint descriptions, although obscure and hard to verify, are too important to overlook, particularity since debate over hadrosaur speeds currently focuses only on a single, apparently ambiguous trackway. Hindlimb/foot ratios and stride-length estimates based on comparisons with other animals should be modified using actual measurements of hadrosaurs. Mesaverde trackway data indicates that hadrosaurs were usually slow moving, although this does not imply that they were incapable of running. The frequency and preferred orientation of their prints suggests high relative abundance and gregarious group activity (herding), which was probably an effective defense strategy. Footprints of a carnosaur are also associated with those of the hadrosaurs.

Resource assessment for Region 4, Colorado Plateau : Menefee Mountain - Weber Mountain area GRA 11 / - Wallaby Enterprises.; Mountain States Mineral Enterprises.; United States. (1983)
The BLM has adopted a two-phase procedure for the integration of geological, energy and minerals (GEM) resources data for suitable/nonsuitable decisions for wilderness study areas (WSA's).

Plant reproduction and optimal foraging: experimental nectar manipulations in Delphinium nelsonii - Marian A. Zimmerman (Oikos, 1983)
Delphinium nelsonii Greene (Ranunculaceae) individuals which were watered produced significantly more nectar per flower than did control individuals. The watered plants also set significantly more seeds per flower than did the controls. Hand pollinations suggest that the seed set difference was due to the increased nectar volume rather than to watering directly. Bumblebee pollinators' responses to the increased standing crop of reward were consistent with predictions from optimal foraging theory and explain the increase in seed set. Pollinators both visited more flowers per inflorescence and spent more time in flowers on nectar-rich plants relative to controls. These results imply that D. nelsonii individuals could increase the female component (i.e. seed set) of plant fitness by increasing their nectar production rate. The results do not, however, allow an accurate assessment of the male component (i.e., pollen donation) of fitness.

Colonization in a pika population: dispersal vs. philopatry - B. L. Ivins; Arthur E. Smith (Behavioral Ecology, 1983)
Relative tendencies toward dispersal or philopatry in a marked population of alpine mammals, the pika (Ochotona princeps), were investigated over a 3-year period in the Rocky Mountains of Colorado to help understand their low intrapopulation genetic variability.

Thermoregulation and flight in Colias butterflies: elevational patterns and mechanistic limitations - J. G. Kingsolver (Ecology, 1983)
This study identifies the physical determinants of thermoregulation in Colias, develops and tests models that predict the patterns of body temperature and flight activity along an elevational gradient, and explores the relationship of the thermoreGulatory characteristics to these patterns among Colias populations.

The Nest Chemistry of Two Seed-Dispersing Ant SPecies - D. C. Culver; A. J. Beattie (Oecologia, 1983)
It is suggested the relocation to Myrmica nests, rich in phosphorus, potassium and nitrogen, may result in greater survivorship of seedlings, and the hypothesis that relocation of ant-dispersed seeds into ant nests may be advantageous to the plant species involved is suggested.

Dynamics of Lotic Ecosystems - B. L. Peckarsky (1983)

Frequency and density of yellow violets - A. Head (1983)

Resource assessment for Region 4, Colorado Plateau : Dominguez Canyon/Adobe Badlands/Camel Back area GRA 6 / - Mountain States Mineral Enterprises.; Wallaby Enterprises.; United States. (1983)
The BLM has adopted a two-phase procedure for the integration of geological, energy and minerals (GEM) resources data for suitable/nonsuitable decisions for wilderness study areas (WSA's).

Ant nest site choice - A. S. Daggett (1983)

The occurrence of annuals and perennials in a subalpine system - Marcy L. McCall (1983)

The timing of seed dispersal in Viola nuttallii: attraction of dispersers and avoidance of predators - C. L. Turnbull; D. C. Culver (Oecologia, 1983)
The hypothesis that a sychrony of the time of seed dispersal and the period when most ants (mutualists) and least rodents (predators) are active would be advantageous to the plant species is discussed.

Avian reproduction over an altitudinal gradient. II. Physical characteristics and water loss of eggs - S. D. Garber; E. L. Thompson; Francis, James; C. Carey (Physiological Zoology, 1983)
Although the effective diffusion coefficient for gases is inversely related to barometric pressure, rates of daily water loss during natural incubation and final water contents of pipped embryos are independent of altitude in eggs of redwinged blackbirds (Agelaius phoeniceus) breeding from sea level to 3,050 m. These results indicate that the increase in diffusion of water vapor from the egg has been offset in some manner in populations of this species breeding at high altitudes. Eggs of redwinged blackbirds and robins (Turdus migratorius) breeding from sea level to 3,050 and 3,450 m, respectively, were analyzed for eggshell conductance, egg mass, water content, shell thickness, and incubation temperature. Of these, eggshell conductance showed the only meaningful relation to barometric pressure and may serve to control rates of gaseous diffusion at high altitudes.

Nectar reward and pollinator specificity - Kenneth L. Jones (1983)

Adaptation at specific loci. III. Field behavior and survivorship differences among Colias PGI genotypes are predictable from in vitro biochemistry - M. S. Swan; R. C. Casin; W. B. Watt (Genetics, 1983)

A comparison of stream productivity - M. Duff (1983)

Handbook of experimental pollination biology - James D. Thomson (1983)

Intraspecific competition in Androsace septentrionalis - B. Eiseman; A. S. Daggett; Kenneth L. Jones (1983)

Dynamics of Lotic Systems - J. D. Allan (1983)

Vegetational diversity and succession of mine tailing slopes and natural earthflow areas: a comparison - C. Richard; J. Hickman (1983)

Concentration of glucosinolates in relation to habitat and insect herbivory for the native crucifer Cardamine cordifolia - J. E. Rodman; S. M. Louda (Biochemical Systematics and Ecology, 1983)
It is suggested that the insect herbivore guild on Cardamine cordifolia responds to concentration and composition of glucosinolates and exerts its greatest pressure on plants with lower concentrations.

The dispersion of nectar resources as a result of bumblebee foraging - Kenneth L. Jones (1983)

Spatial and Behavioral Foraging Patterns and Diet Selectivity in the Social Yellow-Bellied Marmot - B. A. Frase (1983)

Pollination Biology - Nickolas M. Waser (1983)

Stream Ecology - J. D. Allan (1983)

Water Quality of the Upper East River and Copper Creek, Gunnison County, Colorado - B. L. Peckarsky (1983)

A laboratory study of the foraging behavior of Peromyscus maniculatus - J. D. Gerut; A. S. Daggett (1983)

Study of population structures in Rocky Mountain butterflies - A. Dagget; B. Eiseman; A. Head; J. D. Gerut; M. Duff; Cynthia S. Jones; Kenneth L. Jones (1983)

Seed Dispersal by Ants in the Rocky Mountains - C. L. Turnbull; F. M. Hanzawa; A. J. Beattie (Southwestern Naturalist, 1983)
-Field tests quantifying the behavioral responses of ants to the seeds of twenty Rocky Mountain species were conducted in Gunnison County, Colorado. The results indicate that Claytonia lanceolata Pursh, Corydalis aurea Willd., C. caseana A. Gray., Delphinium nelsoni Greene, and Viola nuttallii Pursh are myrmecochores. The seeds of these species all bear a conspicuous elaiosome and are selectively removed by three species of ants, Formica podzolica Francoeur, Formica canadensis Francoeur, and Myrmica discontinua Weber. These are the first records of ant dispersal from the Rocky Mountains. Comparatively little is known about the ant dispersed (myrmecochorous) plant species of the western United States. Scattered reports suggest that they may be common in some areas, particularly the arid south-west (Berg, 1966; Bullock, 1974; O'Dowd and Hay, 1980; Nesom, 1981) and the moist north-west (Nordhagen, 1959; Berg, 1972). Almost nothing is known about ant dispersal in the Rocky Mountains. Serna

Searching in a patchy environment: food plant selection by Colias p. eriphyle butterflies - M. L. Stanton (Ecology, 1982)

A comparison of distances flown by different visitors to flowers of the same species - Nickolas M. Waser (Oecologia, 1982)
There is no evidence that flight characteristics depend on anything as straightforward as whether flower visitors have high or low energetic requirements, and all the visitors to a given plant species fly similar, short distances between successively visited flowers and plants.

Interactions of rufous hummingbirds (Selasphorus rufus) and broad-tailed hummingbirds (Selasphorus platycercus) - S. Olson (1982)

Population and habitat studies of two endemic plants in the Gunnison River Basin, Colorado - W. F. Grey (Journal of the Colorado-Wyoming Academy of Sciences, 1982)

Overlap summary indices and the detection of community structure - K. Rusterholz; James D. Thomson (Ecology, 1982)
Overlaps in resource use have been used to summarize community structure. It is ofen desirable to compare the amount of intensity of overlaps (or other pairwise measures such as competition coefficients) in different communities, especially in the context of comparing actual communities to "neutral model" simulations. We show that the most commonly used index for such comparisons, the mean pairwise overlap, is often unsuitable, and suggest alternate approaches.

Facultative deposition of an oviposition-deterring pheromone by Hylemya - Marian A. Zimmerman (Environmental Entomology, 1982)

Optimal foraging: random movement by pollen collecting bumblebees - Marian A. Zimmerman (Oecologia, 1982)
The data indicate that bumblebees exhibit great plasticity in foraging behavior and that they are able to forage efficiently under a wide range of environmental conditions.

The role of field stations in the preservation of biological diversity - Peter F. Brussard (BioScience, 1982)
Journal Article The Role of Field Stations in the Preservation of Biological Diversity Get access Peter F. Brussard Peter F. Brussard Search for other works by this author on: Oxford Academic Google Scholar BioScience, Volume 32, Issue 5, May 1982, Pages 327–330, https://doi.org/10.2307/1308849 Published: 01 May 1982 Article history Accepted: 23 February 1982 Published: 01 May 1982

Optimal foraging: a test in bumblebees - D. Singleton (1982)

Genetic variation within and between populations of an alpine grasshopper, Aeropedellus clavatus - K. J. Hamrick (1982)

Aquatic Toxicology and Hazard Assessment: Fifth Conference - T. Colburn (1982)

Resource partitioning in bats - R. Justin (1982)

Flower constancy in bees: yes or no? - T. Symons (1982)

Aquatic Toxicology and Hazard Assessment - T. E. Colborn (1982)

Effects of size divergence on competition between Rocky Mountain ant species - D. Singleton (1982)

The ecological implications of size differences in two herbivorous mammals - D. Singleton (1982)

Measurements of low levels of molybdenum in the environment using aquatic insects - T. Colburn (Bulletin of Environmental Contamination and Toxicology, 1982)

Avian reproduction over an altitudinal gradient: incubation period, hatchling mass, and embryonic oxygen consumption - C. M. Vleck; E. L. Thompson; Francis, James; C. Carey (Auk, 1982)

A study of interference competition among two ant species, Formica canadensis and Myrmica in Gothic, Colorado - J. Molofsky (1982)

Marmots and coyotes: behavior of prey and predator - Kenneth B. Armitage (Journal of Mammalogy, 1982)
Journal Article Marmots and Coyotes: Behavior of Prey and Predator Get access Kenneth B. Armitage Kenneth B. Armitage Division of Biological Sciences, University of Kansas, Lawrence, KS 66045 Search for other works by this author on: Oxford Academic Google Scholar Journal of Mammalogy, Volume 63, Issue 3, 26 August 1982, Pages 503–505, https://doi.org/10.2307/1380453 Published: 26 August 1982 Article history Received: 12 June 1981 Accepted: 19 October 1981 Published: 26 August 1982

Yes, but is it art? (or, ectoparasites of small mammals) - Steven J. Taylor (1982)

Growth and Growth Control Effects on Air Quality in Boulder County, Colorado - David Greenland (Journal of Environmental Systems, 1982)

Hydrothermal alteration and oil show at the Summer Coon intrusive center, Saguache County, Colorado - Trygve Loken (Journal of Chemical Theory and Computation, 1982)
The effects of a static external electric field on the ground state electronic structure of a porphine-quinone (PQ) complex have been studied by using density functional theory (DFT). The energies of the excited states have been calculated with time-dependent density functional theory (TDDFT) and with the approximate coupled cluster singles and doubles (CC2) method. The geometries of porphine and quinone have been optimized with B3LYP. The influence of the external electric field on the PQ complex has been studied at six different intermolecular distances between 2.5 and 5.0 Å with the BH&HLYP functional. An external electric field clearly affects the orbitals localized mostly on quinone but not the orbitals localized on porphine. Additionally, the effect of the external field increases with the increasing intermolecular distance. The optical absorption spectrum of porphine obtained by using the BH&HLYP functional is consistent with the Gouterman model and with the spectrum previously

A comparison of pollen and fluourescent dye carryover by natural pollinators of Ipomopsis aggregata - Mary V. Price; Nickolas M. Waser (Ecology, 1982)

Some energetic aspects of behavior in a montane hummingbird nesting habitat - S. M. Hiebert; W. A. Calder (National Geographic Society Research Reports, 1982)

Foraging behavior of bumblebees and hummingbirds - M. Stenger (1982)

Relationship of mist netting capture rates in aspen woods to levels of insolation, precipitation and temperature fluctuations - E. Mayer; J. Chin (1982)

A tale of two nests: observations on the natural history and behavior of the tree swallow (Irdoprocne bicolor) and violet-green swallow (Tachycineta thalassina) (Hirandinidae) of Gothic, - G. R. Flannery (1982)

Local geographic distributions of bumblebees near Crested Butte, Colorado: competition and community structure - G. H. Pyke (Ecology, 1982)
It was hypothesized that the local geographic distributions of bumblebees near Crested Butte, Colorado and the community patterns exhibited by these bumblebees are the products of competition for plants. To evaluate this hypothesis several transects were established and at regular intervals throughout a summer growing season, data were collected along each transect on how many bumblebees of each species and caste were visiting the various plant species. The distributions and abundances of the plant species involved were recorded qualitatively. Seven species of bumblebees accounted for 97% of all bumblebees observed and in this paper attention is restricted to these species. Five other species were observed in very low numbers. Each bumblebee species had a different distributional pattern. The seven bumblebee species form four groups in terms of both their proboscis lengths and the corolla lengths of the plants they preferentially visit. Long—, medium—, and short—tongued groups were mos

Parental investment in Cinclus mexicanus at 2-Mile Bridge: egg laying to fledging - M. Schnee (1982)

Polymorphism for pollen color of Erythronium grandiflorum - C. Crompton (1982)

Constancy of bumblebees - A. Bertozzi (1982)

A Key to the aquatic insects of the streams in the vacinity of the rocky mountain biolociacl lab - D. J. Conlkin; S. I. Dodson; B. L. Peckarsky (1982)

The effect of nectar production on neighborhood size - Marian A. Zimmerman (Oecologia, 1982)
Differences in foraging behavior observed on two plant species with similar floral and inflorescence structures increase the neighborhood size for nectar producing species and make it increasingly unlikely that random drift will be a dominant mode of evolution in populations of these species.

Experimental studies of pollen carryover: hummingbirds and Ipomopsis aggregata - Mary V. Price; Nickolas M. Waser (Oecologia, 1982)
It is concluded that presence of pollen on recipient flowers significantly reduces the average number of subsequent flowers reached by donor pollen.

Patterns of visitation by animal pollinators - James D. Thomson (Oikos, 1982)
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Directional foraging in hummingbirds - R. Rusler (1982)

The organic geochemistry and water-rock system across a contact metamorphic profile in the Mancos shale near Crested Butte, Colorado - John Lee Cuddihee (Rice University's digital scholarship archive (Rice University), 1982)
A Mid-Tertiary igneous intrusion into the Upper Cretaceous Mancos Shale provides an excellent natural laboratory to study the thermal effects of an intrusion on the organic geochemistry and water-rock system across a contact metamorphic profile. The intrusion, is believed to have established a high temperature gradient across a two mile long sampling profile. This study investigated the isotopic and chemical evolution of both kerogen and extractable organic material. Kerogen displayed a net weight loss of 11% due to methane generation. Kerogen showed essentially no carbon isotopic change. Bitumen contents decreased dramatically across the profile with a measurable 1.5 per mil depletion in 12C for the highest temperature samples. The relatively unique time-temperature history of the study area, and the difference in the kinetics of bitumen and kerogen degradation, is believed to be responsible for the difference in behavior of kerogen and bitumen. Oxygen isotope ratios of matrix calcite

Social dynamics of juvenile marmots: role of kinship and individual variability - Kenneth B. Armitage (Behavioral Ecology, 1982)
A population of eight juvenile female yellow-bellied marmots was introduced into a marmot locality from which all other marmOTS were removed and the individual behavioral profile of each animal was determined by mirror image stimulation.

CRC Handbook of Census Methods for Terrestrial Vertebrates - Kenneth B. Armitage (1982)

Feeding habits and prey consumption of three predaceous stoneflies (Plecoptera) in a mountain stream - J. D. Allan (Ecology, 1982)
The feeding ecology of predaceous stoneflies was investigated over 18 mo in Cement Creek, Colorado, USA. Three species were studied at each of three sites over their entire life cycles to elucidate any differences due to species and site. Diet typically changed, over the course of development, from diatoms and chrionomids in the earliest instars, to primarily chironomids, to a broader diet in which mayflies increased in importance relative to chironomids. Stonefly diet was similar in individuals of a given size at a particular site, regardless of species, but differed among size categories and sites within a species. Two factors appeared to determine what prey were eaten. The maximum size of prey ingested increased with size of stonefly, at approximately 10% of predator body mass. No evidence of preference for larger prey was observed within a predator size category, however. Rather, the availability of prey depends upon the abundance of the vulnerable size class, which in turn is affe

Aquatic insect predator-prey relations - B. L. Peckarsky (BioScience, 1982)
Aquatic insects have numerous adaptations reflecting the coevolution of predators and prey. Predators have a wide variety of search, capture, and consumption mechanisms, and prey demonstrate various physical, chemical, and behavioral defenses. Mortality in prey populations from predation may be significant. Although most aquatic insect predators are opportunists, certain prey sizes or types may be preferred, suggesting predator influence on prey community structure.

Exploration and geology of the Mt. Emmons molybdenite deposits, Gunnison County, Colorado - John T. Galey; John A. Thomas (Economic Geology, 1982)
During the period 1970 to 1976, three stockwork molybdenite deposits were discovered beneath Mt. Emmons, a prominent peak of the Elk Mountains in the central portion of the Colorado mineral belt. Two of the deposits are below Redwell Basin on the northwestern side of the mountain and the third, and richest, deposit is under Red Lady Basin on the southeast side of Mt. Emmons.The uppermost molybdenite deposit in Redwell Basin is at a depth of about 2,400 ft, where it is associated with a small cupola of rhyolite porphyry. The cupola is expressed at the surface by a composite breccia pipe which appears to have been fed through a zone of crackled hornfels lying between the base of the pipe and the apex of the cupola. Rhyolite porphyry in the cupola grades downward into granite porphyry of the Redwell stock. The lower molybdenite deposit is about 1,000 ft below the west-dipping contact of the stock.The molybdenite deposit under Red Lady Basin is a contact-related stockwork draped over the g

Interference competition between two colonies of ants - D. Rutherford (1982)