Yellow-bellied marmots as prey of coyotes - D. H. Van Vuren (American Midland Naturalist, 1991)
-Analysis of contents of 395 coyote (Canis latrans) scats collected for 6 yr at a subalpine locality in Colorado showed that yellow-bellied marmots (Marmota flaviventris) were a regular and frequent prey of coyotes during summer. There was no evidence that marmots were especially vulnerable to predation by coyotes during the mating season or during the time of dispersal. Marmots were most vulnerable to predation during July, for unknown reasons. Marmots apparently served as alternate prey of coyotes; marmot occurrence in scats was greatest during years when gophers, probably a preferred prey of coyotes, were infrequent in scats.

Duration of snow cover and its influence on life-history variation in yellow-bellied marmots - D. H. Van Vuren; Kenneth B. Armitage (Canadian Journal of Zoology, 1991)
We evaluated the relationship between growing-season phenology, as indicated by time of snow melt, and intrapopulation variation in reproduction and growth of yellow-bellied marmots. The time of snow melt explained significant proportions of the variation in frequency of reproduction (78%), litter size (79%), and estimated body mass of young of the year (68%), but not growth rate. We suggest that the duration of snow cover, through its effect on the length of the growing season, influences habitat quality; marmots living at localities with prolonged snow cover have a shorter season of access to food. The variation in life-history traits is attributed to phenotypic plasticity and not to local genetic variation.

Heterogeneity among floral visitors leads to discordance between removal and deposition of pollen - P. Wilson; J. D. Thomson (Ecology, 1991)
Flowers are often visited by many species of animals.
These sometimes differ in size, behavior, and other
characteristics that translate into differences in their effectiveness as pollinators. The differences
may be manifest in their effect on reproductive
success either through female or through male function. A number of recent studies have measured
pollen removal as a component of male function however, high pollen removal need not result in high
subsequent deposition of the removed pollen or in high
success at siring seeds. Here we provide an example in
which pollen-collecting bees remove more pollen but
deposit less of it than nectar-collecting bees. The pollen
collectors are antagonists with regard to the male reproductive success of the plants, at least relative to the
more beneficent nectar collectors. Our results underscore
the need to study pollen deposition in conjunction
with pollen removal.

Metamunirite, a new anhydrous sodium metavanadate from San Miguel County, Colorado - Howard T. Evans (Mineralogical Magazine, 1991)
AbstractMetamunirite, β-NaVO3, is found in cavities in sandstone in San Miguel County, Colorado, occurring as fine, fibrous, colourless needles. X-ray powder and precession photographs show the crystals to be orthorhombic, space group Pnma, with a = 14.134(7), b = 3.648(2), c = 5.357(2) Å. They are optically biaxial positive with nα = 1.780(2) (‖c), nβ = 1.800(2) (‖a), nγ ≫ 185 (‖b, fibre axis; positive elongation), 2Vz moderate. A crystal structure analysis, confirming the previously determined structure of β-NaVO3, shows the presence of (VO3)n chains made up of zig-zag VO5 square pyramids. Metamunirite is probably formed by dehydration of munirite, NaVO3.2H2O.

A profile of persistence: territorial hummingbirds - W. A. Calder (National Geographic Research and Exploration, 1991)

Geochemical equilibria of iron in sediments of the roaring river alluvial fan, Rocky Mountain National Park, Colorado - M. Iggy Litaor; R. B. Keigley (Earth Surface Processes and Landforms, 1991)
AbstractIron geochemistry of the sediments and interstitial waters of the Roaring River alluvial fan in the Rocky Mountain National Park, Colorado was studied using a chemical equilibria approach. Large concentrations of colloidal Fe in the filterable Fe of the interstitial waters results in considerable overestimation of Fe2 + activity. The overestimation of Fe(II) seriously hampered the usefulness of chemical equilibria approach in the study of Fe geochemistry. Buried soil organic matter and a high water table within the alluvial fan has produced a highly reduced environment which results in elevated colloidal and filterable iron concentrations in the interstitial waters. The source of the iron is probably iron oxides within the buried soil and primary iron‐bearing minerals in the sediments. When the iron‐rich solutions reach the surface, the water rapidly oxidizes and amorphous ferric hydroxides precipitate. Between 190 to 370 mmol of iron per kg of surficial material were precipita

Determinants of spatial distribution in a population of the subalpine butterfly Oeneis chryxus - G. C. Daily; P. R. Ehrlich; D. R. Wheye (Oecologia, 1991)

Seasonal changes in CSF insulin concentrations in marmots: insulin may not be the satiety signal for fasting in winter - G. L. Florant; R. D. Richardson; Shannon A. Mahan; L. W. Singer; S. C. Woods (American Journal of Physiology, 1991)

Consequences of larval intraspecific interference to stonefly growth and fecundity - B. L. Peckarsky; C. A. Cowan (Oecologia, 1991)

Seasonal glucose uptake in marmots (Marmota flaviventris): the role of pancreatic hormones - K. Tokuyama; H. L. Galantino; R. Green; G. L. Florant (Comparative Biochemistry and Physiology, 1991)

Sex allocation in Pseudocymopterus montanus: why mountain parsley relies more on secondary umbels for female reproductive fitness - D. Cordray (1991)

Species-area effects on talus slopes: island biogeography in reverse - J. C. Herz (1991)

Resource availability and gender variation among flowers on inflorescences of Aquilegia caerulea - S. L. Reynolds (1991)

Animal memory and spatial mapping of the least chipmunk - James J Roberts (1991)

Variation in receptive stigma time after pollination of Aquilegia caerulea - G. Shair (1991)

Trends in Ecology - B. L. Peckarsky (1991)

Temperature differences between Salix and Lathyrus habitats - S. Horne (1991)

Social behavior and space-use of ground-dwelling squirrel species with different levels of sociality - L. S. Rayor; Kenneth B. Armitage (Ethology, Evolution and Ecology, 1991)
Comparisons among young of ground-dwelling squirrel species with different adult sociality indicate patterns of interaction during development that may influence the evolution of complex sociality. Social behavior and spatial overlap of weaned young with their mothers, littermates, non-littermate young, and adult conspecifics were compared among Gunnison's prairie dogs (Cynomys gunnisoni), yellow-bellied marmots (Marmota flaviventris), Columbian ground squirrels (Spermophilus columbianus), and thirteen-lined ground squirrels (S. tridecemlineatus). The adult social organization of these species differs markedly: Gunnison's prairie dogs are highly social, yellow-bellied marmots and Columbian ground squirrels are relatively less social, and thirteen-lined ground squirrels are asocial. In young Gunnison's prairie dogs, social cohesion and spatial overlap were high not only with the mother and littermates, but with all members of the harem. In yellow-bellied marmots, social cohesion occurre

Mud puddling by butterflies is not a simple matter - C. L. Boggs; L. A. Jackson (Ecological Entomology, 1991)
Two sets of hypotheses based on sodium limitation have been proposed to explain the sexual dimorphism in puddling hchaviour, which suggested that males have a greater need for sodium in neuroniuscular activity because they spend a larger time in flight than females.

Dominant flower colors: shade vs. sun - Michaela Johnson (1991)

Effects of floral traits on sequential components of fitness in Ipomopsis aggregata - Diane R. Campbell (American Naturalist, 1991)
The total number of viable, undamaged seeds released by a plant provides an estimate of female reproductive success (RS). I outline a method for analyzing pollinator-mediated selection based on partitioning female RS into four multiplicative components: number of flowers, pollen received per flower, number of seeds set per grain of pollen received, and number of undamaged seeds per seed set. I measured these fitness components for individual plants in several populations of Ipomopsis aggregata and estimated the life-cycle components of selection differentials. Plants whose flowers had highly exserted stigmata and spent a high proportion of time in the pistillate phase received more pollen per flower, as estimated by tracking dye. Experimental hand-pollinations showed that female RS was strongly limited by low levels of pollen, confirming the results of other studies. In spite of this pollen limitation, within natural populations female RS did not increase with mean pollen received per

Fitness value of oviposition choice in Nicrophorus americanus - R. Kramer (1991)

The reality of the "switching" model, or, whatever happened to delayed gratification? - R. Lyons (1991)

The predation impact of Tamiasciurus hudsonicus on nest site selection - R. Lyons (1991)

The importance of aspen root abundance and palatability in excluding northern pocket gophers from aspen groves - G. Marrujo (1991)

Analysis of nectar standing crop in Helenium hoopsii: spatially independent standing crop variation over time - F. R. O'Keefe (1991)

Pre-dispersal seed predation by Hylema (Delia) sp. (Diptera: Anthomyiidae): mechanisms and consequences of oviposition choice - Alison K. Brody (1991)

Components of Phenotypic Selection: pollen export and flower corolla width in Ipomopsis aggregata - Diane R. Campbell; Nickolas M. Waser; Mary V. Price; E. A. Lynch; R. J. Mitchell (Evolution, 1991)
Diane R. Campbell, Nickolas M. Waser, Mary V. Price, Elizabeth A. Lynch, Randall J. Mitchell, Components of Phenotypic Selection: Pollen Export and Flower Corolla Width in Ipomopsis aggregata, Evolution, Vol. 45, No. 6 (Sep., 1991), pp. 1458-1467

City-County Consolidation Issues in Colorado: The GRIP Studies - M. R. Fuller (Public Productivity & Management Review, 1991)

A field test of resource depression by predatory stonefly larvae - B. L. Peckarsky (Oikos, 1991)
Experiments were conducted in two Rocky Mountain streams (Gunnison County, Colorado) to determine the context within which predatory stonefly larvae locally depress their prey populations. In feeding trials where no migration of prey (Baetis bicaudatus, Ephemeroptera) was allowed from flow-through boxes containing natural substrates, Megarcys signata and Kogotus modestus (Perlodidae) significantly depressed prey densities over 14 and 38 h, respectively. However, increasing predator density had no apparent effect on per capita predation rate. In 1984 enclosure experiments allowing prey but not predator migration, Kogotus significantly reduced total prey density and that of two relatively sedentary prey species (Cinygmula mimus, Ephemeroptera, Heptageniidae, and Zapada haysi, Plecoptera, Nemouridae) during three-day trials

Toxics A to Z: A Guide to Everday Pollution Hazards - J. Harte; C. E. Holdren; R. Schneider; C. Shirley (1991)

Age or pollinator manipulation causing banner petal color change in Lupinus argentus (Fabaceae) - N. Bernard (1991)

Vegetation comparison of an earth slump with surrounding areas - V. Seidman (1991)

The relation of resource density to exploration time in the least chipmunk - J. P. Crews (1991)

Energy reallocation in reproductive function of Ipomopsis aggregata after loss of floral tissue - S. Griggs (1991)

Effects of "nectar guides" on pollinator visitation and seed set - A. Keller (1991)

A test of the central-place foraging theory and observations on the foraging behavior of Formica obscuripes - L. Lind (1991)

Female choice in true bugs (Homoptera: Miridae) - C. Wong (1991)

The importance of host plant phenology on the survival and growth rate of Glaucopysche lygdamus - D. R. Wilson (1991)

The effects of floral morphology on interspecific pollen transfer in Ipomopsis - T. Davidson (1991)

Carcass utilization by two species of carrion beetle - K. K. Agnew (1991)

Comparing pollen dispersal and gene flow in a natural plant population - Diane R. Campbell (Evolution, 1991)
Estimates of realized gene flow and pollen dispersal to stigmas in the same natural populations of Ipomopsis aggregata subsp.

The effects of patterns of flower coloration on insect variation - A. Keller; G. Shair; K. Horst (1991)

Competition and intraguild predation between two species of caddisfly larvae (Trichoptera) in permanent and semi-permanent high elevation ponds - G. B. Sparks (1991)

Seed dispersal in four Rocky Mountain herbaceous perennials: wind dispersal in Erythronium grandiflorum and ant dispersal in Corydalis aurea, Delphinium nelsonii, Viola nuttalli - G. D. Weiblen (1990)

Pollen-pollen and pollen-style interactions during pollen tube growth in Erythronium grandiflorum (Liliaceae) - M. B. Cruzan (American Journal of Botany, 1990)
Using pairs of pollen donors, I analyzed the growth of pollen tubes growing in different channels of the same style in Erythronium grandiflorum. After 24 hr the length of pollen tubes of randomly selected pollen donors was affected by the presence of other donors. The mean pollen tube lengths of donors did not differ when taken across all of the donor pairings, but in individual pairs, pollen from one donor was often significantly longer than pollen from the other donor when tested across several recipients. Pollen tube lengths were also consistently longer for pollen paired with pollen from the same donor than when paired with pollen from other donors, apparently because of mutual stimulation between the pollen populations from the same plant. In a second experiment, the amount of pollen tube attrition after five days of growth of pollen from a donor growing near (within 3 m) the recipient depended upon the source of other pollen growing in the same style. Local pollen experienced mor

Oxygen consumption and body temperature in yellow-bellied marmot populations from montane-mesic and lowland-xeric environments - Kenneth B. Armitage; J. C. Melcher; J. M. Ward (Journal of Comparative Physiology B, 1990)
Yellow-bellied marmots minimize thermoregulatory costs by concentrating activity at times when the microclimate is favorable, by tolerating hyperthermia at high TA in the field, and by having a conductance lower than that predicted from body size.

Effects of enclosures on stream microhabitat and invertebrate community structure - B. L. Peckarsky; M. A. Penton (Journal of the North American Benthological Society, 1990)
During summers 1984, 1985, and 1988 we tested the effects of stainless steel mesh enclosures on the microhabitat and composition of the invertebrate community (community structure) at a third-order site on the East River, Gunnison County, Colorado. Comparisons of substrate composition, interstitial flow rates, periphyton on stones, coarse detritus accumulation, and benthic invertebrate community structure were made between enclosed and unenclosed habitats, and among enclosures remaining in the stream for different lengths of time. Surface flow rates were not a good predictor of interstitial flow through substrates inside or outside enclosures, and interstitial flow rates inside enclosures were significantly lower than those of the adjacent unenclosed habitat. Due to reduced flow rates, enclosures were detritus sinks, accumulating significantly more coarse detritus than in surrounding substrates. This difference became more pronounced as enclosures were exposed for longer periods. Simil

The impact of artificially creating an elk wintering ground on plant species diversity - D. Irwin; C. H. Floyd; W. Huresky (1990)

Epibiotic euglenoid flagellates increase the susceptibility of some zooplankton to fish predation - R. L. Willey; P. A. Cantrell; S. T. Threlkeld (Limnology and Oceanography, 1990)
The phototrophic flagellate, Colacium vesiculosum (Euglenophyceae), lives externally on freshwater zooplankton. In experimental tanks with supplemental nutrients, epibiotic prevalence (% zooplankters infested with epibionts) was not consistently different from control. Experimental reduction of the zooplankton population did not reduce epibiont frequencies; no substrate limitation is suggested. In tanks with planktivorous fish, Menidia beryllina, prevalence was significantly reduced on Daphnia, Ceriodaphnia, and cyclopoid copepods. The pump-filter-feeding fish, Tilapia aurea and Dorosoma cepedianum, reduced prevalence on Ceriodaphnia and copepod nauplii, but only Dorosoma reduced prevalence on cyclopoids. Impacts of fish predation appear to be related to the effects of Colacium on visibility and escape efficiency.

Plasma and white adipose tissue lipid composition in marmots - G. L. Florant; L. C. Nuttle; D. E. Mullinex; R. A. Rintoul (American Journal of Physiology, 1990)
White adipose tissue biopsies and plasma samples were obtained from hibernating yellow-bellied marmots (Marmota flaviventris) maintained in the laboratory. In addition, biopsies and plasma samples were obtained from normothermic animals in the field and laboratory. Measurement of plasma free fatty acid (FA) levels indicated that winter laboratory animals exhibited increased lipolysis. Additionally, analysis of white adipose tissue triacylglycerol revealed that the FA composition of the storage fat in animals maintained on the standard laboratory diet is remarkably simple and uniform between different adipose depots in the same animal. Three FAs (palmitic, oleic, and linoleic acids) made up greater than 95% of the total. Triene (alpha-linolenate) was found in newly captured animals, but the percentage of this FA decreased rapidly when the animals were maintained on the standard laboratory diet. Throughout the hibernation season (October to April), white adipose tissue-saturated FA perce

Hypotheses for the evolution of dioecy in seed plants - J. D. Thomson; J. Brunet (Trends in Ecology and Evolution, 1990)
Future correlational studies must explicitly consider phylogeny and should also be supplemented by detailed studies of particular transitions to dioecy - studies of the sort that have clarified analogous issues such as heterostyly.

Ochotonoa princeps - A. T. Smith; M. L. Weston (Mammalian Species, 1990)

Test of copper toxicity on caddisfly larvae - B. Fennerty; C. Sickel; R. Seagrist; C. Tonielli (1990)

A cross-section of opinions about the ecology of Crested Butte - V. C. Minick (1990)

Prey exchange rates and the impact of predators on prey populations in streams - S. D. Cooper; S. J. Wilde; B. L. Peckarsky (Ecology, 1990)
We present four lines of evidence that the magnitude of prey exchange (=immigration/emigration) among substrate patches has an overwhelming influence on the perceived effects of predators on prey populations. (1) An extensive review of the literature on predation effects in benthic and littoral freshwater revealed a significant relationship between prey exchange rate and observed predator impact. In streams, studies showing significant predator effects used cages with smaller mesh sizes than studies showing nonsignificant effects. Similarly, there was a highly significant correlation between cage mesh size and the magnitude of predator impact on common prey. Large—scale stream studies indicated that prey drift and colonization rate were inversely related to predator impact on benthic prey. (2) These patterns were confirmed by field experiments and observations where mesh size was directly manipulated or where exchange rates varied among taxa. In Colorado streams we saw greater predator

Dispersal of yellow-bellied marmots - D. H. Van Vuren (1990)

Wetlands restoration project - C. Tonielli; R. Seagrist; B. Fennerty (1990)

Camping impacts on vegetation - A. Lowrance (1990)

A brief study of CO2 and methane flux of a sub-alpine meadow, RMBL - T. Larscheid (1990)

Wetlands restoration project - W. Huresky; C. H. Floyd; C. Tonielli; B. Fennerty; D. Irwin; R. Seagrist (1990)

A study of the impact of recreational use on the public trails of the Crested Butte area - A. Frankel (1990)

The effects of cattle grazing on montane meadows - P. Barry; B. Fennerty; R. Seagrist; C. Tonielli (1990)

Symposium: Dynamics of Ecology of Free-Living Protozoa - J. Cairns; J. R. Pratt (1990)

Hematological adaptation to Hypoxia in Peromyscus and Microtus at high and low altitude. - S. M. Wyckoff; B. A. Frase (Transactions of the Illinois Academy of Science, 1990)

Variation in pollen size, fertilization ability and postfertilization siring ability in Erythronium grandiflorum - M. B. Cruzan (Evolution, 1990)

The adaptive significance of sexual reproduction in plants - P. Bierzychudek (Lectures on Mathematics in Life Sciences, 1990)

Rabbits, Hares and Pikas: Status Survey and Conservation Action Plan - A. T. Smith; N. A. Formozov; Robert S. Hoffmann; Z. Changlin; M. A. Erbajeva (1990)

The effect of inflorescence size on pollinator visitation of Delphinium nelsonii and Aconitum columbianum - J. Pleasants; Marian A. Zimmerman (Collectanea Botanica (Barcelona), 1990)

Thermal Influences on the Activity and Energetics of Yellow-Bellied Marmots (Marmota flaviventris) - J. C. Melcher; Kenneth B. Armitage; W. Porter (Physiological Zoology, 1990)

Tardigrada from Gunnison Co., Colorado, with the description of a new species of Diphascon - C. W. Beasley (Southwestern Naturalist, 1990)

Perspectives on plant competition - S. M. Louda; K. H. Keeler; R. D. Holt (1990)

Nectar standing crops in Delphinium nelsonii flowers: spatial autocorrelation among plants? - Nickolas M. Waser; R. J. Mitchell (Ecology, 1990)
Several aspects of nectarivore foraging behavior have been interpreted as responses to spatial reward patchiness of the kind documented for Delphinium nelsonii floral nectar by Pleasants and Zimmerman (1979). Working with this same species over 3 yr, however, we were unable to detect substantial pattern in nectar standing volumes, either through contingency analyses or spatial autocorrelation. Although spatial outocorrelations between rewards of neighboring plants were positive in 5 or 6 samples examined, only one value was statistically significant. Spatial autocorrelations over longer distances were erratic. We used computer simulations of nectarivores foraging in a large plant population to explore factors that promote reward patchiness. Simulations suggest that moderate patchiness will develop at all but extremely low or high flower visitation rates. Rates were intermediate at our sites and those of Pleasants and Zimmerman, however, so visitation intensity does not seem to explain

A general model of the role of male-donated nutrients in female insects' reproduction - C. L. Boggs (American Naturalist, 1990)
Male insects of many species donate nutrients to their females at mating, and the females can use these nutrients for egg production and somatic maintenance. These male-derived nutrients represent male investment in reproduction. The relative investment by each sex in reproduction has been postulated to be a determinant of the mating system and possible operation of sexual selection. However, the effect of male nutrient donations on female fitness is not well understood. I examine the effect on female fitness of male nutrients donated at mating in terms of the role of male nutrients in the female's nutrient budget for egg production. Nonnutritional constraints on total egg mass, the timing of egg production, the quality and quantity of adult female feeding, and alternative functions of male nutrient donations are incorporated into a model describing the role of male-derived nutrients. The model predicts the conditions under which changes in the availability of male-derived nutrients to

Biological Approaches and Evolutionary Trends in Plants - P. Bierzychudek (1990)

Pollination efficiency and effectiveness of bumblebees and hummingbirds visiting Delphinium nelsonii - Nickolas M. Waser; Mary V. Price (Collectanea Botanica (Barcelona), 1990)

Feeding of a lotic mayfly grazer as quantified by gut influorescence - C. A. Cowan; B. L. Peckarsky (Journal of the North American Benthological Society, 1990)

Colorado Potato Beetle Control, Johnston County, 1988 - Kenneth A. Sorensen; K. A. Kidd (Insecticide and Acaricide Tests, 1990)
Abstract 'Atlantic' potatoes were planted 14 Apr, near Benson, NC. Single row plots, 10 ft long on 42 inch centers were replicated 4 times in a randomized complete block design. Alleys of 5 ft separated replicates. Treatments were applied using a CO2 pressurized sprayer with a single hollow cone nozzle (18 × ) operating at 60 psi to apply 80 gal/acre. Treatments were applied 24 May (all treatments), 31 May (Trident, Trident + Nufilm, and M-One, 2 rates), 8 Jun (Trident, Trident + Nufilm, M-One, 2 rates, and Rotenox), 1 Jul (all), and 6 Jul (Trident, Trident + Nufilm, and M-One, 2 rates). Visual estimates of foliar damage and/or insects counts were made 30 May, 6, 13, 20, 27 Jun, 5, 11, and 25 Jul. Adults were counted by walking the length of the plot and counting all visible adults. Egg masses and larvae were counted on 3 hills/plot. Small larvae were estimated to be 1st and 2nd instars, and large 3rd and 4th. Potatoes were harvested and yields recorded on 25 Jul.

Allogenic controls on the evolution of storm to tidal shelf sequences in the Early Proterozoic Uncompahgre Group, southwest Colorado, USA - CHARLES W. Harris; KENNETH A. ERIKSSON (Sedimentology, 1990)
ABSTRACTDominantly coarse‐grained, shallow‐marine, metasedimentary rocks of the Early Proterozoic Uncompahgre Group (UG) record periods of shoaling and drowning on different temporal scales that are attributed to episodic long‐term oscillations in relative sea‐level with superimposed shorter duration excursions in relative sea‐level. Long‐term events are probably tectonic whereas short‐term events are eustatic.The 2–5 km thick Uncompahgre Group consists of 250–600 m thick, dominantly coarse‐grained quartzite units (Q1–Q4) and 200–300 m thick mudstone/pelite units (P1–P5). Five depositional systems comprise the Uncompahgre Group. The outer shelf system (OSS) is composed of Bouma‐type beds and intercalated mudstones that are transitional vertically to parallel‐laminated to wave‐rippled sandstones and hummocky cross‐stratified sandstones of the inner shelf system (ISS). Trough cross‐stratified sandstones comprise the shoreface system (SHS). The tidal inner shelf/shoreface system (TIS/SHS)

Polyphase suprastructure deformation in metasedimentary rocks of the Uncompahgre Group: Remnant of an early Proterozoic fold belt in southwest Colorado - CHARLES W. Harris (Geological Society of America Bulletin, 1990)
Research Article| May 01, 1990 Polyphase suprastructure deformation in metasedimentary rocks of the Uncompahgre Group: Remnant of an early Proterozoic fold belt in southwest Colorado CHARLES W. HARRIS CHARLES W. HARRIS 1Department of Geological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061 Search for other works by this author on: GSW Google Scholar Author and Article Information CHARLES W. HARRIS 1Department of Geological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1990) 102 (5): 664–678. https://doi.org/10.1130/0016-7606(1990)102<0664:PSDIMR>2.3.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation CHARLES W. HARRIS; Poly

Crassulacean acid metabolism: a preliminary study at high altitude - M. Taylor (1990)

Conditional mutualism: density- and quality-dependent responses of aphids to tending by ants - L. M. Breton (1990)

The role of fly pollination in montane habitats - C. A. Kearns (1990)

Stonefly predation along a hydraulic gradient: a test of the harsh-benign hypothesis - B. L. Peckarsky; S. C. Horn; B. Statzner (Freshwater Biology, 1990)
SUMMARY. 1. Microhabitat preferences of predatory stoneflies and four prey taxa were assessed by taking benthic samples along a hydraulic gradient in a Black Forest stream in West Germany. Densities of predator and prey species were estimated at twenty‐one hydraulic regimes.2. Enclosures containing the stonefly, Dinocras cephalotes, and control cages with no predators were placed in the substrate at hydraulic regimes favourable and unfavourable to predators. Cages received initial prey communities that were obtained from benthic samples taken at hydraulic regimes matching those intended for each cage.3. Population densities of the two most numerically important prey taxa, the mayfly. Baetis rhodani, and the Chironomidae, were reduced in the presence of Dinocras, but only when enclosures were placed in the hydraulic regimes favourable to the predator. Thus, predation effects increased as the hydraulic regime became more benign to the predators.4. Densities of two other prey species rar

The hummingbird's restraint: a natural model for weight control - L. L. Calder; L. L. Calder; T. D. Frazier (Experientia, 1990)
In July, cessation of territorial activity was accompanied by a regular upward drift of dawn weight, suggesting that weight had been regulated previously as a balance between expenditure and intake, perhaps without involving set-points.

Camp Bird Mine Ouray County, Colorado - Tom Rosemeyer (Rocks & Minerals, 1990)

A proposed plan for the restoration/reclamation of the Gunnison City Airport wetlands - C. Dulin; E. W. Schweiger (1990)

Potamodromy and Reproduction of Colorado Squawfish in the Green River Basin, Colorado and Utah - Harold M. Tyus (Transactions of the American Fisheries Society, 1990)
Movements of Colorado squawfish Ptychocheilus lucius were studied by radio-tracking and recapturing tagged fish in the Green River basin of Colorado and Utah, 1980–1988. Of 153 fish tracked, 63% were highly mobile: 41% migrated to known spawning sites, 11% migrated to suspected spawning sites, and 11 % moved to other locations. Nonmigratory behavior of tracked fish (18%) was linked with non-annual spawning or sexual immaturity. Contact was lost with 14% of the fish, but five that were lost one year migrated in subsequent years. Some fish (5%) were radio-tagged after the spawning season. Spawning migrations began about 28 d after highest spring flows when water temperatures were 9°C or greater. Movement offish to spawning areas (N = 63) averaged 140.7 km (range, 32–372.8 km) in downstream (73%) and upstream (23.8%) directions, and some fish (3.2%) moved downstream in tributaries, then upstream in the mainstream. An autumn-to-spring home range was indicated by radiotelemetry and recaptur

Gender specialization of flowers within inflorescences of hermaphroditic plants - J. Brunet (1990)

Genetic Effects on Aging, II - W. A. Calder (1990)

A strategy for predicting watershed acidification - J. W. Kirchner (1990)

Distances travelled by drifting mayfly nymphs: factors influencing return to the substrate - J. D. Allan; B. P. Feifarek (Journal of the North American Benthological Society, 1989)
We determined the distance travelled by drifting nymphs of the mayflies Baetis and Cinygmula to add to existing knowledge of factors influencing drift distance, and to investigate the influence of drift-exiting behavior upon drift magnitude and periodicity. Individuals were released into the water column of a trough at 0.5-m intervals above the exit point, and numbers remaining in suspension over each release distance were fit to a previously developed model which describes return to the substrate according to a negative exponential function. Drift distance increased with increasing current velocity (range studied: 5-55 cm/s) and with decreasing body size (range studied: ca. 0.1-1 mg dry wt) according to log-linear functions. At higher velocities (35 and 55 cm/s), nymphs of both species drifted much shorter distances alive than dead, indicating active exiting from the drift. Drift distances of live nymphs scarcely differed between day and night, which contradicts the suggestion that gr

The mating biology of a mass-swarming mayfly - J. D. Allan; A. S. Flecker (Animal Behaviour, 1989)
Investigation of this mating system in Epeerus longimanus, a mayfly of the western United States that forms swarms that are quite large, finds that swarm locations are not explainable as feeding or emergence sites, but they do correlate with landscape features.

Course Book, Rocky Mountain Field Biology, 1989 - Mary V. Price; Nickolas M. Waser (1989)

Deployment of ovules and pollen among flowers with inflorescences - J. D. Thomson (Evolutionary Trends in Plants, 1989)

CRP: A Baca County, Colorado perspective - Stephen O. Myers; P. Lorenz Sutherland (Journal of Soil and Water Conservation, 1989)
THE Conservation Reserve Program (CRP) and conservation compliance provisions of the 1985 Food Security Act have had a dramatic impact in Colorado. As of May 1989, landowners in the state had enrolled more than 1.8 million acres in the CRP. Baca County, in southeastern Colorado, has the greatest number of acres enrolled of any county in the United States, according to Agriculture and Stabilization and Conservation Service (ASCS) records. The CRP has received mixed reviews in Baca County. Known historically as the geographic center of the Dust Bowl and for its continued high rates of soil erosion ( 2 ), the county exceeded the 25 percent county acreage limit during the third CRP sign-up in August 1986. As of May 1989, operators had 601 CRP contracts on 266,851 acres. Baca County is characterized by high temperatures, high winds, and erratic precipitation. The challenge of establishing permanent vegetative cover on CRP acres is a major one. At Springfield, the average annual air temper

Early warning lowers risk of stonefly predation for a vulnerable mayfly - B. L. Peckarsky; M. A. Penton (Oikos, 1989)
Behavior of Baetis bicaudatus (Ephemeroptera; Baetidae) was video taped in a western Colorado, USA stream to identify the specific stimuli eliciting noncontact responses to predatory stoneflies (Kogotus modestus; Plecoptera; Perlodidae). In situ behavioral and feeding trial experiments were also conducted to assess the effect of removal of Baetis cerci on these responses to predators, on measured reactive distances, and on the vulnerability of Baetis to stonefly predation. Predatory stimuli tested included live stoneflies (tethered and untethered), stonefly models (plasticized), excised fresh stonefly antennae, and wires. Intact Baetis primarily turned their cerci (tail curl behavior) with similar frequencies toward live or model stoneflies that were between 1 and 2 cm downstream, and primarily moved when stoneflies were within 1 cm even before contact. Removal of Baetis' cerci reduced the frequency of tail curl responses and the reactive distance, but increased the frequency of moveme

Intra- and interspecific competition for mutalists: ants as a limited and limiting resource for aphids - J. H. Cushman; J. F. Addicott (Oecologia, 1989)
It is shown that ants are a Limited and Limiting resource for a tended aphid species and that fireweed aphids compete with intra-and interspecific aphid neighbors for the services of ant mutualists.

Evolutionary options for maximizing pollen dispersal of animal-pollinated plants - L. Harder; J. D. Thomson (American Naturalist, 1989)
On the average, nectar-collecting bumble bees deposited 0.6% of the pollen removed from the flowers of Erythronium grandiflorum (Liliaceae) onto the stigmas of subsequently visited flowers. Because the proportion deposited declined as the amount removed increased, an individual plant would maximize its total pollen dispersal by relying on many pollen-removing visits while limiting the pollen removed by each pollinator. This restriction of pollen removal could be achieved by a plant presenting only a small portion of its pollen at one time (packaging) and/or by limiting the amount of presented pollen that a pollinator removes during a single visit (dispensing). The restriction of pollen removal required to maximize the expected total deposition on stigmas depends on the number of pollinator visits a plant receives, variation in the frequency of visits, and the pattern of pollen removal during a series of visits. Many aspects of floral biology contribute to a plant's ability to restrict

Floral color change in Lupinus Argenteus (Fabaceae): Why should plants advertise the location of unrewarding flowers to pollinators? - D. F. Gori (Evolution, 1989)
I examined the adaptive significance of two floral traits in the perennial herb, Lupinus argenteus: 1) the retention of corollas on "spent" flowers, i.e., flowers containing inviable pollen, unreceptive stigmas, and negligible pollinator rewards and 2) a change in corolla color of retained "spent" flowers, which is restricted to a spot on the banner petal. At anthesis, this spot is yellow, and approximately four days later, it changes to purple. After the change, purple flowers remain on plants an additional 5-7 days before corolla abscission occurs; purple flowers were avoided by pollinators, presumably because they contained less pollen (rewards) than yellow ones. I experimentally tested the hypothesis that purple flowers contribute to the floral display of the plant by removing varying numbers of spent flowers and assessing the effect on pollination visitation. Pollinators preferentially approached and foraged on plants with greater numbers of flowers per inflorescence; they did not

A Famous Quartz Locality Rediscovered: The Ohio Mine, Ouray County, Colorado - Robert Stoufer; Tom Rosemeyer (Rocks & Minerals, 1989)
Click to increase image sizeClick to decrease image size Additional informationNotes on contributorsRobert StouferRobert Stoufer, a long-time mineral collector, owns a mineral and gift shop in Ouray, Colorado.Tom RosemeyerTom Rosemeyer, owner of Red Mountain Exploration, writes the "Through the 'Scope" column in Rocks & Minerals.

Yellow-bellied marmots are generalist herbivores - B. A. Frase; Kenneth B. Armitage (Ethology, Ecology and Evolution, 1989)
Yellow-bellied marmots (Marmota flaviventris) eat a wide variety of grasses, forbs, and seeds, but do not feed on all items in proportion to their abundance in the environment. In this study, relationships between the marmot diet and estimated protein, water, caloric value, relative biomass, and toxicity of the available plant species were investigated. The epidermis of all forb species did not survive digestive processes equally well; therefore, a quantitative analysis of the animals' diet based on fecal sampling was precluded. However, observations of where marmots feed and limited data from fetal analysis indicate that marmots chose their food plants on the basis of relative abundance, phenology, rejection or low ingestion of plant species with defensive compounds, nutritional quality, and energy requirements. Water content is unlikely to affect diet choice except during prolonged drought.

Survey of Reproducing Populations Containing Neotenic Morphs of the Salamander, Ambystoma Tigrinum nebulosum, in the Gunnison Basin of Colorado - R. L. Willey; S. C. Horn; B. D. Inouye (1989)

Towards a More Exact Ecology - N. E. Pierce (1989)

Testing the 'mimicry' explanation for the Colias 'alba' polymorphism: platability of Colias and other butterflies to wild bird predators - C. Ley; W. B. Watt (Functional Ecology, 1989)
C. Ley, W. B. Watt, Testing the `Mimicry' Explanation for the Colias `alba' Polymorphism: Palatability of Colias and Other Butterflies to Wild Bird Predators, Functional Ecology, Vol. 3, No. 2 (1989), pp. 183-192

Behavior of territorial (Limenitis weidemeyerii (Nymphalidae) within temporary feeding areas - R. H. Rosenberg (J.Lep.Soc., 1989)

Otero County: A demographic history of a Colorado High Plains County, 1889–1987 - Kenneth R. Weber (The Social Science Journal, 1989)
Otero County, situated on the High Plains of eastern Colorado, typifies many rural agricultural counties. This article surveys its history, demography, and social economy during the period from its formation in 1889 to 1987. It compares the county's demographic changes with those of the state and presents the county's changing age composition and net migration patterns. Population composition correlates with economic opportunity. The demographic and economic trends present in Otero, and most other out-lying Colorado counties, run counter to those of the state as a whole.

A field survey of amphibians in the rocky mountains of colorado - G. A. Hammerson (1989)

Implications of recapture data for migration of the rufous hummingbird (Selasphorus rufus) in the Rocky Mountains - W. A. Calder; E. Jones (Auk, 1989)

Possible effects of acidic deposition on a Rocky Mountain population of the tiger salamander Ambystoma tigrinum - J. Harte; E. Hoffman (Conservation Biology, 1989)
Abstract: To investigate possible biological effects of acidic deposition in the western United States, we performed population censuses and dose‐response experiments at a subalpine watershed in the Rocky Mountains of Colorado, An adult tiger salamander (Ambystoma tigrinum nebulosum) population declined by 65% over seven years, while larval recruitment declined over all but the last year of his period A. tigrinum eggs had an LD‐50 pH of 5.6, which is within the range encountered by eggs at this site during snow melt. Although the decline of A. tigrinum at this watershed could be a natural fluctuation, the available evidence is consistent with the bypothesis that acidic deposition is its cause. Thus, the decline of A. tigrinum at the watershed may be the first indication of biological damage from acidic deposition in the western United States

Evolutionary options for maximizing pollen dispersal of animal-pollinated plants - L. Harder; J. D. Thompson (American Naturalist, 1989)
On the average, nectar-collecting bumble bees deposited 0.6% of the pollen removed from the flowers of Erythronium grandiflorum (Liliaceae) onto the stigmas of subsequently visited flowers. Because the proportion deposited declined as the amount removed increased, an individual plant would maximize its total pollen dispersal by relying on many pollen-removing visits while limiting the pollen removed by each pollinator. This restriction of pollen removal could be achieved by a plant presenting only a small portion of its pollen at one time (packaging) and/or by limiting the amount of presented pollen that a pollinator removes during a single visit (dispensing). The restriction of pollen removal required to maximize the expected total deposition on stigmas depends on the number of pollinator visits a plant receives, variation in the frequency of visits, and the pattern of pollen removal during a series of visits. Many aspects of floral biology contribute to a plant's ability to restrict

Seasonal variation in the intensity of competition and predation among dragonfly larvae - S. A. Wissinger (Ecology, 1989)
In nature, both similar and disparate sizes of Libellula lydia and L. luctuosa larvae frequently co—occur in time and space. To determine if these larvae interact as competitors, and/or predators and prey, I used artificial ponds to manipulate density, species composition, and size range of co—occurring larvae. Detailed life history data were used to design separate fall and spring experiments. In both experiments, "competition treatments" contained only larvae similar in size, whereas "predation treatments" contained larvae disparate in size. In fall competition treatments there were no density—dependent growth responses. However, in the spring experiment, larvae of both species grew significantly faster in low density than in high density treatments. This seasonal difference in competition was attributed to fluctuations in resource abundance. Competition did not directly affect survivorship. In spring and fall predation treatments, mortality was significantly higher than it was in co

The broad-tailed Humming bird; a long-term study at Rmbl - L. Calder; D. Bradley-Spencer; L. Calder (Cooper Ornithological society, 1989)

Reversal of apparent feeding preferences of bumblebees by aggression from Vespula wasps - J. D. Thomson (Canadian Journal of Zoology, 1989)

Inflorescence size: test of the male function hypothesis - Diane R. Campbell (American Journal of Botany, 1989)
One explanation for low fruit sets in plants with hermaphroditic flowers is that total flower production by a plant is controlled primarily by selection through male function. This male function hypothesis presupposes that success in pollen donation increases more strongly with flower number than does seed set. I tested this prediction by measuring male and female components of reproductive success as functions of flower number in natural populations of the self‐incompatible, perfect flowered plant, Ipomopsis aggregata. Fruit set in this hummingbird‐pollinated plant averaged 4.9 to 40.3% across the 4 years of study. Both the total amount of pollen donated and the total amount received, as estimated by movement of fluorescent powdered dyes, increased linearly with number of flowers on a plant. Total seed production, however, increased disproportionately quickly because plants with larger floral displays were more likely to set at least one fruit.

Mechanisms of prey selection by stream-dwelling stonefly nymphs - B. L. Peckarsky; M. A. Penton (Ecology, 1989)

Randomizing data and the sequential comparison index - J. Cairns (Water Pollution Control Federation, Research Journal, 1989)

The function of kin discrimination - Kenneth B. Armitage (Ethology, Ecology and Evolution, 1989)
Abstract Kin discrimination should be a tactic in the fitness strategy of individuals. Two postulates derived from inclusive fitness theory that fitness benefits toward kin are correlated with degree of relatedness and that social behavior of members of a kin group is always cooperative are refuted by analyses of the social dynamics of yellowbellied marmots. Cooperative behavior occurs predominantly between mother/ daughter and sister/sister pairs, but such pairs also compete. More distant kin are treated similarly to unrelated animals, social behavior is primarily agonistic. Patterns of space-use, matrilineal formation and organization, social dynamics, and reproductive suppression of close kin suggest that marmots attempt to maximize direct fitness. Keywords: yellow-bellied marmotsdirect fitnessspace-sharingamicable behavioragonistic behaviorrelatedness

Seed protection by ants foraging on the extrafloral nectaries of the aspen sunflower, Helianthella quinquenervis - J. D. Evans (1989)

Spatial scaling in ecology - J. A. Wiens (Functional Ecology, 1989)
Acts in what Hutchinson (1965) has called the 'ecological theatre' are played out on various scales of space and time. To understand the drama, we must view it on the appropriate scale. Plant ecologists long ago recognized the importance of sampling scale in their descriptions of the dispersion or distribution of species (e.g. Greig-Smith, 1952). However, many ecologists have behaved as if patterns and the processes that produce them are insensitive to differences in scale and have designed their studies with little explicit attention to scale. Kareiva & Andersen (1988) surveyed nearly 100 field experiments in community ecology and found that half were conducted on plots no larger than 1 m in diameter, despite considerable differences in the sizes and types of organisms studied. Investigators addressing the same questions have often conducted their studies on quite different scales. Not surprisingly, their findings have not always matched, and arguments have ensued. The disagreements a

Physiology of Cold Adaptation in Birds - T. Bucher; M. Chappell (1989)

Dispersal of Erythronium grandiflorum pollen by bumblebees: implications for gene flow and reproductive success - B. A. Thomson; B. A. Thomson (Evolution, 1989)

Optimal outcrossing in Ipomopsis aggregata: seed set and offspring fitness - Nickolas M. Waser; Mary V. Price (Evolution, 1989)
Restricted gene flow and localized selection should establish a correlation between physical proximity and genetic similarity in many plant populations. Given this situation, fitness may decline in crosses between nearby plants (inbreeding depression), and in crosses between more widely separated plants (outbreeding depression) mostly as a result of disruption of local ad- aptation. It follows that seed set and offspring fitness may be greatest in crosses over an intermediate optimal outcrossing This prediction was supported for Ipomopsis aggregata, a long- lived herbaceous plant pollinated by hummingbirds. In six replicate pollination experiments, mean seed set per flower was higher with an outcrossing distance of 1-10 m than with selfing or outcrossing over 100 m. A similar pattern appeared in the performance of offspring from experimental crosses grown under natural conditions and censused for a seven-year period. Offspring from 1 0-m crosses had higher survival, greater chance of f

Pollen tube attrition in Erythronium grandiflorum - M. B. Cruzan (American Journal of Botany, 1989)
Seed set after selfing in E. grandiflorum is often reduced relative to seed set after crossing; however, the compatibility patterns seen are not due to genes of major effect (i.e., S alleles). There is quantitative variation in the proportion of pollen tubes reaching the base of the style after both self‐ and cross‐pollinations. Pollen tubes require between 24 and 72 hr to reach the ovary, but pollen tube growth ceases after 72 hr. When styles were removed from the ovaries 5 days after pollination, between 10 and 80% of the pollen tubes in the stigma had not reached the base of the style. The number of pollen tubes at the base of the style is a much better predictor of seed set than is the number of pollen tubes in the stigma. Pollen tube attrition is not affected by the age of the recipient flower or by the number of pollen donors contributing to the stigmatic pollen pool. The number of pollen tubes reaching the base of the style is dependent upon the source of the pollen and appears

Germination schedules of pollen grains: implications for pollen selection - J. D. Thomson (Evolution, 1989)
EvolutionVolume 43, Issue 1 p. 220-223 Note and CommentFree Access GERMINATION SCHEDULES OF POLLEN GRAINS: IMPLICATIONS FOR POLLEN SELECTION James D. Thomson, James D. Thomson Department of Ecology and Evolution, State University of New York at Stony Brook, Stony Brook, NY, 11794 Rocky Mountain Biological Laboratory, Crested Butte, CO, 81224Search for more papers by this author James D. Thomson, James D. Thomson Department of Ecology and Evolution, State University of New York at Stony Brook, Stony Brook, NY, 11794 Rocky Mountain Biological Laboratory, Crested Butte, CO, 81224Search for more papers by this author First published: January 1989 https://doi.org/10.1111/j.1558-5646.1989.tb04219.xCitations: 47AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Onlin

Variation in pollen flow within and among populations of Ipomopsis aggregata - Diane R. Campbell; Nickolas M. Waser (Evolution, 1989)

Energy allocation by yellow-bellied marmots - J. C. Melcher; Kenneth B. Armitage; W. Porter (Physiological Zoology, 1989)
Energy intake, daily energy expenditure (DEE), and energy available for production were determined for yellow-bellied marmots (Marmota flaviventris) at three study sites in the Elk Mountains of southwestern Colorado. Energy intake, estimated from tritiated-water turnover rates and the water and energy content of food plants, ranged from 3,283 kJ d⁻¹ for two lactating females in July to 666 kJ d⁻¹ for a yearling female in September. Maintenance, activity, and thermoregulatory components of DEE were estimated from time-budget data, estimated or measured activity costs, and heat-transfer theory. Not including energy allocated to production, DEE ranged from 1,017 kJ d⁻¹ for a lactating female in July to 539 kJ d⁻¹ for a female yearling in June. Time spent in the burrow accounted for 41%-60% of DEE; foraging, for 11% -51%; sitting on rocks by the burrow, for 1%-28%; and thermoregulation, for 1%-6%. Assimilated energy exceeded DEE for all but one animal studied; mass gains calculated assumin

Techniques for immobilizing and bleeding marmots and woodrats - B. A. Frase; D. H. Van Vuren (Journal of Wildlife Diseases, 1989)
Blood samples were obtained in the field by femoral vein puncture in bushy-tailed woodrats (Neotoma cinerea) and yellow-bellied marmots (Marmota flaviventris) that had been injected intramuscularly with ketamine hydrochloride. Dosages ranged from 50 mg/kg for marmots to 30 to 110 mg/kg for woodrats. Sedated animals were handled easily, and a volume of blood sufficient for hematological assays or electrophoresis could be collected.

Measurements of selection in a hermaphroditic plant: variation in male and female pollination success - Diane R. Campbell (Evolution, 1989)
I measured phenotypic selection of floral traits through both male and female functions of the hermaphroditic flowers of Ipomopsis aggregata (Pursh) V. Grant subsp. aggregata (Polemoniaceae). Fluorescent powdered dyes were used to track movement of pollen by hummingbirds and to measure pollen delivery to individual plants as well as pollen receipt. A phenotypic selection analysis revealed that selection due to male-male competition during pollination was capable of delaying flowering date and widening corolla tubes by 0.22 and 0.24 standard-deviation units, respectively, in a single generation. Several floral traits were highly correlated with each other. Multivariate selection analysis suggested that selection through male function directly favored late flowering as well as a sexual expression characterized by a short pistillate phase and long corollas. Selection intensities through male and female functions were of similar overall magnitude during the pollination stage of the life cy

A newPernopecten(Bivalvia: Pectinacea) from the Pennsylvanian Gothic Formation of Colorado - William F. Rice; Jodi A. Milske (Journal of Paleontology, 1989)
An abstract is not available for this content so a preview has been provided. Please use the Get access link above for information on how to access this content.

Small pterosaurs and dinosaurs from the Uncompahgre fauna (Brushy Basin Member, Morrison Formation: ?Tithonian), Late Jurassic, western Colorado - James A. Jensen; Kevin Padian (Journal of Paleontology, 1989)
Small vertebrates were recovered from the matrix encasing specimens of giant sauropod dinosaurs (Supersaurus, Ultrasaurus, Dystylosaurus) collected from the “Dry Mesa” Quarry (Brushy Basin Member, Morrison Formation, western Colorado). Most of the remains appear to pertain to a single form of pterodactyloid pterosaur, Mesadactylus ornithosphyos, n. gen. and sp., the holotype of which is a synsacrum. A bone end from this quarry, first identified as an avian proximal tibia and named Palaeopteryx thomsoni, is reidentified as the distal radius of a small deinonychosaur or bird. A small femur of a small deinonychosaur or bird and additional material of other small vertebrates from this quarry are figured and described.

Rare Books Slavica in the University of Colorado Libraries, Boulder, Colorado. An Annotated Bibliography - Robert H. Davis; Sonia L. Jacobs; Eugene E. Petriwsky (The Slavic and East European Journal, 1989)

Effects of intra-peritoneal transmitter implants on yellow-bellied marmots - D. H. Van Vuren (Journal of Wildlife Management, 1989)
I implanted radio transmitters in 183 yellow-bellied marmots (Marmota flaviventris); transmitters were replaced -<6 times in 73 animals, for 300 surgeries. Surgical procedures were simple, effective, and largely trouble-free. Survival 30 days later was -98%, and growth rates (21 g/day) were the same for animals with or without implants. Pregnancy rate (0.52 litters/yr) and mean litter size (4.3) of implanted females were similar to pregnancy rate (0.48) and litter size (4.2) of females without implants. Intraperitoneal implants offer an alternative to radio collars for yellow-bellied marmots. J. WILDL. MANAGE. 53(2):320-323 Radio telemetry is an important tool in studies of free-roaming mammals. Transmitters typically are attached to animals by external collars; radio collars, however, are impractical for some species because of life-style or body shape (Smith and Whitney 1977). Hence, surgical implantation of sealed, physiologically inert transmitters into the peritoneal cavity has be

Proterozoic geology of the Needle Mountains; A summary - Barbara J. Tewksbury (Geological Society of America eBooks, 1989)
The Early and Middle Proterozoic rocks in the Needle Mountains include three distinct rock sequences (1) multiply deformed bimodal metavolcanic rocks, related sedimentary rocks, and plutonio units, all metamorphosed to medium grade; (2) multiply deformed clastic sedimentary rocks metamorphosed to low grade; and (3) weakly foliated to unfoliated plutonic rocks. Although many important questions remain unresolved, work by a number of individuals suggests the following history. Mafic and silicic volcanics, sediments, and intrusives of the Irving Formation and Twilight Gneiss accumulated at least 1,760 Ma and were multiply deformed and metamorphosed shortly after accumulation. Small post-tectonic plutons of the Tenmile and Bakers Bridge Granites invaded the metavolcanic sequence between 1,680 and 1,700 Ma. The timing of deposition of the conglomerates, clean quartzites, and pelites of the Vallecito Conglomerate and the Uncompahgre Formation with respect to events in the metavolcanic sequen

Tight-Sand Development Potential in the Southern Rulison Area, Garfield County, Colorado - J.R. Duda; J.S. Hancock (Journal of Petroleum Technology, 1989)
Summary Reservoir characterization and simulation of natural gas production were used to assess the production potential for an extension area within the Piceance Creek basin (Garfield County, CO). Many of the basin's reservoirs are lenticular sands characterized as having low porosities, low permeabilities, and relatively high water saturations. One such horizon is the Mesaverde group, which consists of discontinuous sandstone lenses distributed within a shale matrix and is present throughout the Piceance Creek basin. Prior studies of the commercial Rulison field in the east-central portion of the basin indicated that compressional forces created an anticlinal nose aligned northwest/southeast through part of the field. These forces created a conductive natural fracture system that enhances the permeability of the Mesaverde. This paper shows a relationship between Rulison field and an area south of Rulison that encompasses about 36 sq miles [93.2 km]. The area has bee

Spring Control of Cooley Spruce Gall Adelgid on Colorado Blue Spruce in Berks County, 1988 - P. R. Heller; S. Kellogg (Insecticide and Acaricide Tests, 1989)
Abstract Fourteen treatments were applied to evaluate Cooley spruce gall adelgid on heavily infested 5-6-ft Colorado blue spruce Christmas trees. Each treatment was applied on 6 Apr to 4-tree replicates. Foliar treatments were completed by using a Solo Master 412 mistblower. Treatments were applied at 2 rates as follows: 74.3 gal/acre (225 ml/tree) and 148.6 gal/acre (450 ml/tree). At treatment time the following conditions existed; air temperature, 65°F; 68% RH; water pH 5.0; skies were clear and sunny. Posttreatment counts were made 21 Sep. Each replicate was evaluated by counting and recording the number of new (1988) galls formed on each replicate.

Genetic differentiation of populations of Weidemeyer’s admiral butterfly. - R. H. Rosenberg (Canadian Journal of Zoology, 1989)
I assessed the genetic differentiation of populations of Weidemeyer's admiral butterfly (Limenitis weidemeyerii) in central and eastern Colorado by using starch-gel electrophoresis. Wright's F-statistics indicated that there was significant differentiation, both within and between years, among the same populations analyzed for 2 successive years, and among populations, even those in close geographic proximity. Consequently, no correlation was found between the genetic identities and geographic distances between pairs of populations. To explain the genetic structure of populations, I estimated patterns of movement and effective sizes of populations. I assessed movement of individuals by using mark–recapture techniques, which indicated that travel over the season for both sexes was negligible (range 0–2850 m, mean 166 m). I estimated effective population sizes by using Pollak's methods, and as would be expected for populations with territorial social systems, effective sizes were small (

Sources of variation in plant reproductive success, and implications for concepts of sexual selection - E. E. Lyons; Nickolas M. Waser; Mary V. Price; J. Antonovics; A. F. Melton (American Naturalist, 1989)
There is growing evidence of nonrandom reproductive success in plants. The potential evolutionary effect of these patterns depends on the extent to which they reflect nonrandom transmission of genes between generations. A recent tendency has been to examine these patterns in the context of sexual selection. We present an experimental protocol designed to yield more information on nonrandom transmission in general and on sexual selection as a special case. The mainstays of the protocol are twofold. First, reproduction is separated into pollination, fertilization, and seed-maturation phases, in which functional processes associated with the genders are known and in which the genders can be manipulated. Second, sources of variation in reproductive success are identified by systematically repeating a reciprocal-crossing design with treatments that alter the intensity with which males and/or females can interact. We discuss appropriate experimental and analytic techniques, especially design

Testing the "mimicry" explanation for the Colias "alba" polymorphism: patterns of co-occurrence of Colias and Pierine butterflies - W. B. Watt; C. Kremen; P. A. Carter (Functional Ecology, 1989)
W. B. Watt, C. Kremen, P. Carter, Testing the `Mimicry' Explanation for the Colias `alba' Polymorphism: Patterns of Co-Occurrence of Colias and Pierine Butterflies, Functional Ecology, Vol. 3, No. 2 (1989), pp. 193-199

Evolutionary Aspects of Huerfano Butte Colorado - Dolores G. Durant (MacSphere (McMaster University), 1989)
Gabbroic dyke and syenitic plug intrusives have been sampled and studied across Huerfano Butte. Petrography and geochemical analyses were performed on selected specimens; from these analyses chemical variation diagrams have been prepared. Crystal Size Distribution analyses have been done on magnetites and olivines to determine crystal nucleation and growth rate in the dyke. These data have been used to infer aspects of the evolution of Huerfano Butte.

Stonefly nymphs hydrodynamic cues to discriminate between prey - B. L. Peckarsky; R. S. Wilcox (Oecologia, 1989)
This study is the first to document the use of hydrodynamic cues by stream-dwelling predators for discrimination of prey from nonprey and provides a mechanism to explain selective predation by stoneflies on Baetis in nature.

Evidence for apomixis in Arabis - B. A. Roy; H. L. Rieseberg (Journal of Heredity, 1989)

Environmental sensitivity of sexual and apomictic Antennaria: do apomicts have general-purpose genotypes? - P. Bierzychudek (Evolution, 1989)

Living in the Cold - G. L. Florant; K. Tokuyama; D. A. Rintoul (1989)

Complex population differentiation in checkerspot butterflies (Euphydryas spp.) - Peter F. Brussard (Canadian Journal of Zoology, 1989)
Gel electrophoresis was used to obtain an estimate of the genetic similarity among populations of Euphydryas anicia, Euphydryas chalcedona, and Euphydryas colon in an effort to determine whether they should be considered separate species or arbitrary groupings of populations in a single polytypic species. The average genetic distances between these entities, which collectively are referred to as the "ACC complex," are of the magnitude found between insect subspecies rather than between insect species. Furthermore, these entities show no unique combinations of morphological or biochemical characters that permit all individuals to be assigned with assurance to a specific taxon. Although cases of apparent reproductive isolation between some sympatric populations within the ACC complex have been reported, they appear to be terminal populations of "rings of races," rather than points of contact between completely isolated reproductive units. We recommend that the ACC complex be treated as a

Melatonin profile in marmots: the influence of catecholamines, hibernation, and light - G. L. Florant (Journal of Pineal Research, 1989)
The aim of this study was to determine the effects of circulating catecholamines and light on the daily melatonin rhythm in the marmot. Endogenous levels of circulating catecholamines and plasma melatonin were measured during arousal from hibernation in light and stuthes were performed on the circadian melatonin rhythm in two photoperiods (LD 4:20 and LD 8:16). In addition, stuthes were done on the capacity of broad‐band white light at normal room intensities (32 μm2 or 108 lx) and of low‐intensity monochromatic green light (500 nm; 1.4 μm2 or 31 lx) to suppress high nocturnal melatonin levels. We conclude that high levels of plasma catecholamines that occur during arousal from hibernation do not influence the production and secretion of pineal melatonin. During the nocturnal portion of its light/dark cycle, the marmot plasma melatonin rhythm is suppressed by both white light and low‐intensity green light.

Why predaceous stoneflies do not aggregate with their prey - B. L. Peckarsky (Verhandlungen der Internationale Vereinigung fr Theoretische und Angewandte Limnologie, 1988)

Male body size and mating success in swarms of the mayfly Epeorus longimanus - A. S. Flecker; J. D. Allan; N. L. McClintock (Holarctic Ecology, 1988)

Ecological Aspects of Social Evolution - Kenneth B. Armitage (1988)

Behavior of the ground-dwelling ant Formica canadensis upon habitat displacement - K. Crumpton (1988)

The Colorado breeding bird survey: a study in species diversity - H. Delfiner (1988)

Behavior of nesting red-tail hawks - A. Radvany (1988)

A study of cold tolerance in Chamerion angustifolium and Ipomopsis aggregata - M. Sowa (1988)

Conservation of pollinators and petal shed in blue flax (Linum lewisii) - J. Boles (1988)

Foraging behavior associated with predation risk in the golden-mantled ground squirrel and the least chipmunk - A. Hanson (1988)

Montane grassland butterflies: a survey of nectar feeding rates - D. Reeder (1988)

Manica mutica in Gunnison County, Colorado - Joan M. Herbers (1988)

Paleokarst-Controlled Ore in Central Colorado - Gary P. Landis; Richard J. Tschauder (1988)
Abstract We propose that many Tertiary man to orebodies typical of Leadville and adjacent districts of Central Colorado (northern Sawatch range and Mosquito range) are modifications to pre-existing mineralized paleokarst cave systems (Tschauder and Landis, 1985; Landis and Tschauder, 1985). Major karst cave development occurred in this region during mid- to late- Mississippian time. Cave breccia mineralization (as an integral part of cave fill) is observed to dominate in Paleozoic caves located away from the influence of Tertiary intrusions (Breece Hill Center, Leadville; Buckskin stock, Alma district). Most data and many observations on the nature of this Paleozoic cave breccia mineralization are based upon access in the Sherman mine to the east of the inferred Leadville paleokarst system. However, the overprint of Laramide through mid-Tertiary ore deposition associated with intrusive centers has obscured much of the evidence for earlier cave-hosted mineralization. Tertiary mineraliza

Spatial and temporal patterns of floral inconstancy in plants and populations of Ipomopsis aggregata (Polemoniaceae) - N. C. Ellstrand; R. J. Mitchell (Botanical Gazette, 1988)
To determine whether floral part numbers (merism) vary over time within inflorescences, we scored merism of the petals, sepals, stamens, and carpels of all flowers on the same 10 plants of Ipomopsis aggregata in three Colorado populations weekly through most of the 1984 flowering season. At least one flower in 93% of the plants had abnormal merism, and 6.1% of the 2,164 flowers scored displayed abnormal merism. Floral inconstancy varied substantially over sites and dates, but not among individual plants. At all three sites, plants showed the most floral variation on the first sampling date. The corolla was the most variable flower part. The temporal changes in floral merism observed may have either developmental or environmental origins.

Petrology of flecked gneisses in the northern Wet Mountains, Fremont County, Colorado - ROBERT B. TRUMBULL (Geological Society of America Bulletin, 1988)
Research Article| February 01, 1988 Petrology of flecked gneisses in the northern Wet Mountains, Fremont County, Colorado ROBERT B. TRUMBULL ROBERT B. TRUMBULL 1Department of Geology, University of New Mexico, Albuquerque, New Mexico 87131 Search for other works by this author on: GSW Google Scholar Author and Article Information ROBERT B. TRUMBULL 1Department of Geology, University of New Mexico, Albuquerque, New Mexico 87131 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1988) 100 (2): 247–256. https://doi.org/10.1130/0016-7606(1988)100<0247:POFGIT>2.3.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation ROBERT B. TRUMBULL; Petrology of flecked gneisses in the northern Wet Mountains, Fremont County, Colorado. GSA Bulletin 1988;; 100 (2): 247–256. doi: htt

A River No More: The Colorado River and the West, by Philip L. Fradkin [Review] - R. M. Baxter (The Canadian field-naturalist, 1988)
(Uploaded by Plazi from the Biodiversity Heritage Library) No abstract provided.

Rehabilitating Damaged Ecosystems, Vol. II - David W. Inouye (1988)

Sevier-age ramp-style thrust faults at Cedar Mountain, northwestern San Rafael swell (Colorado Plateau), Emery County, Utah - K. R. Neuhauser (Geology, 1988)
Research Article| April 01, 1988 Sevier-age ramp-style thrust faults at Cedar Mountain, northwestern San Rafael swell (Colorado Plateau), Emery County, Utah K. R. Neuhauser K. R. Neuhauser 1Department of Earth Sciences, P.O. Box 179, Fort Hays State University, Hays, Kansas 67601 Search for other works by this author on: GSW Google Scholar Author and Article Information K. R. Neuhauser 1Department of Earth Sciences, P.O. Box 179, Fort Hays State University, Hays, Kansas 67601 Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1988) 16 (4): 299–302. https://doi.org/10.1130/0091-7613(1988)016<0299:SARSTF>2.3.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation K. R. Neuhauser; Sevier-age ramp-style thrust faults at Cedar Mountain, northwestern Sa

Distribution and species diversity of trichomycete gut fungi in aquatic insect larvae in two Rocky Mountain streams - R. W. Lichtwardt; M. C. Williams (Canadian Journal of Botany, 1988)
At least 20 species of Trichomycetes (Zygomycotina) were dissected from the hindguts and peritrophic membranes of larval Diptera (Simuliidae, Chironomidae), Ephemeroptera, and Plecoptera in two high-altitude streams, and the trichomycete species diversity in the two streams was compared. Periodic sampling of larvae over a 6-week summer period showed that some gut fungi are widely distributed in their respective host types, whereas other fungal species are more localized. Insect populations had infestations that varied from low to as high as 100% of the insects dissected, depending on the fungal species. There was no general increase over time, from early to late season, in fungal species diversity or percentage of larval infestation, nor were larvae in second- and third-order sites of one stream generally more infested than in a first-order site in that stream.

Pollination biology in the Snowy Mountains of Australia, with comparisons with montane Colorado, USA - David W. Inouye; G. H. Pyke (Australian Journal of Ecology, 1988)
AbstractVarious aspects of the pollination biology of the alpine flora of Kosciusko National Park, NSW, were examined from late December 1983 until the end of March 1984, including flowering phenology, corolla tube lengths, flower colour, ultraviolet reflectance patterns, visitation rates to the flowers and proboscis lengths of the flower‐visiting insects. An average of 5.3 species flowered in each of 13, 2 m×2 m montane plots and 5.6 species in the 13 alpine plots. The maximum number in flower simultaneously averaged 4.1 species in the montane and 3.3 in the alpine plots; flowering peaked in mid‐January, Corolla tube lengths of the flora averaged 1.73 mm.The most common floral colour was white or predominantly white (40 species), followed by yellow (14 species). Only six of the 38 species (16%) examined had some type of reflectance pattern; the remaining species all absobed ultraviolet.Flies appeared to be the major pollinators. The insects collected in the study area comprised 60 spe

Comparative pollen and dye transfers by pollinators of Delphinium nelsonii - Nickolas M. Waser (Functional Ecology, 1988)

Habitat selection and colony survival of Microsiphum valeriana Clarke (Homoptera: Aphidae) - M. F. Antolin; J. F. Addicott (Annals of the Entomological Society of America, 1988)

Spatial segregation of the sexes of dioecious plants - P. Bierzychudek; V. Eckhart (American Naturalist, 1988)
Several recent studies have shown that males and females in some populations of dioecious plants are spatially segregated with respect to an environmental gradient. The inference is often made that such spatial segregation of the sexes (SSS) is favored by selection because it reduces competition between individuals of opposite sex (sexual "niche partitioning"). This paper was written to clarify the evolutionary interpretation of cases of SSS. We describe the possible proximate mechanisms capable of producing SSS and evaluate their plausibility. Then, we identify the selective factors that could favor the evolution of SSS. We argue that SSS can be favored if male fitness and female fitness respond differently across environments (because of differences in reproductive biology), that a reduction in competition between males and females is unlikely to be an evolutionary cause of SSS, and that differential mortality is unlikely to evolve as a proximate mechanism for achieving adaptive SSS.

Plant Reproductive Ecology: Patterns and Strategies - M. A. Schlessman (1988)

Resource allocation in Silene acaulis - Kirk C. Anderson (1988)

Territorial songs of the white-crowned sparrows - M. McNairn (1988)

Forest vegetation of the Gunnison and parts of the Uncompahgre National Forests : a preliminary habitat type classification - Robert R. Alexander; Barry C. Johnston; Rocky Mountain Forest; Range Experiment Station (Fort Collins, Colo.) (1988)
A vegetation classification based on a combination of concepts and methods developed by Braun-Blanquet and Daubenmire was used to identify 37 tentative forest habitat types on the Gunnison National Forest. Woodland habitat types comprised two series with a total of 3 habitat types, and forest habitat types included nine series with a total of 34 habitat types. A key to identify the habitat types is provided and the management implications associated with each are discussed.

Some thoughts on the identification of Gunnison's Red-backed Hawk (Buteo polyosoma) and why it's not a natural vagrant - S. E. Allen (Colorado Field Ornithologist, 1988)

Red-naped sapsuckers feeding at willows: possible keystone herbivores - P. R. Ehrlich; G. C. Daily (American Birds, 1988)

The Ecology of Social Behavior - Kenneth B. Armitage (1988)

The effect of melatonin on growth rates of post-natal deer mice - Ian Billick (1988)

Territories and behaviors of red-wing blackbirds - A. B. Good (1988)

Male and female parental nest attendance rates in the red-naped sapsucker - L. Miller (1988)

Effect of trout predation on the short term colonization of enclosures by aquatic invertebrates - E. W. Schweiger (1988)

Prey preference in stoneflies: a comparative analysis of prey vulnerability - J. D. Allan; A. S. Flecker (Oecologia, 1988)
Values increased with increasing size of the predator, and inclusion of the C/A term indicated that predators would obtain greater reward from small relative to large prey, and from dipterans relative to mayflies.

Recent Collecting Activity in San Juan County, Colorado - John Muntyan; John Muntyan (Rocks & Minerals, 1988)
A considerable quantity of fine specimen material has been obtained from a number of San Juan County mines and prospects during the last decade, in spite of the fact that commercial activity has almost ceased.

Discovery of sexual reproduction in an unusual new species of Stachylina (Trichomycetes) - R. W. Lichtwardt (Mycologica, 1988)

Adaptation at specific loci. V. Metabolically adjacent enzyme loci may have very distinct experiences of selective pressures - P. A. Carter; W. B. Watt (Genetics, 1988)
Abstract The polymorphic phosphoglucomutase (PGM) and glucose-6-phosphate dehydrogenase (G6PD) loci have been studied in parallel to experimental work on the phosphoglucose isomerase (PGI) polymorphism in Colias butterflies. PGI, PGM and G6PD are also autosomal in Colias. PGM and G6PD are loosely linked (and represent the first identified autosomal linkage group in Colias); they assort independently from PGI. Recombination occurs in both sexes. Neither PGM nor G6PD shows large, consistent differences in flight capacity through the day among its genotypes, as PGI does. PGM shows some change of allele frequencies, and match to Hardy-Weinberg expectation, with air temperature in middle and latter parts of the season, but not early in the season. G6PD may show some heterozygote excess over Hardy-Weinberg expectation early in the day, but more testing is needed. No evidence for differential survivorship was seen at PGM or G6PD, in contrast to PGI. At the PGM and G6PD loci, ma

Rehabilitating Damaged Ecosystems - J. Cairns (1988)

Microphysical Effects of Wintertime Cloud Seeding with Silver Iodide over the Rocky Mountains. Part III: Observations over the Grand Mesa, Colorado - Arlin B. Super; Bruce A. Boe (Journal of Applied Meteorology, 1988)
During March 1986, several airborne and ground-based silver iodide (AgI) seeding experiments were conducted over the Grand Mesa, Colorado, during a three-day period of northerly flow and shallow orographic cloud. While little natural snowfall was observed during these experiments, supercooled liquid water formed over the windward slopes and evaporated to the lee of the mesa of many hours. Seeding-induced microphysical changes coincident with the AgI plumes were found in all eight experiments, (including two that employed ground-based seeding) by aircraft sampling about 500 m above the mesa top. Precipitation rates estimated from ice particle images at light levels suggested increases within the seeded volumes in all but one experiment. Surface precipitation increases were observed in three aircraft seeding experiments and one ground-based seeding experiment that coincided with the passage of AgI plumes aloft. Surface observations were not possible during the other ground-based seeding

Population biology of Aquilegia micrantha - A. Seidl (1988)

The comparison of activity time between the breeding season and pre-migratory - D. A. Lepo (1988)

Rhizome patterning in the cow lily, Veratrum californicum L. (Durand) - K. Henderson (1988)

Life Histories Behavior and Space Partitioning in Selected Species of Western North American Plecoptera - Rodney L. Hassage (University of North Texas Digital Library (University of North Texas), 1988)
Five species of stoneflies (Zapada haysi, Plumiperla diversa, Taenionema pacificum, Isoperla petersoni, Arcynopteryx compacta) from the North Slope and Interior of Alaska were examined for seasonal patterns of emergence of adults and growth of nymphs. Generally growth was retarded during the winter in this region, and all species except I. petersoni completed growth prior to January. The life cycles of six stonefly species (Prostoia besametsa, Triznaka signata, Sweltsa coloradensis. Isoperla fulva, Skwala parallela, Claassenia sabulosa) are described from northern New Mexico. In this region growth was generally less retarded during the winter than in Alaska; P. besametsa completed all nymphal growth during late fall and winter. Drumming behavior of a Colorado population of Pteronarcella badia was described using an evolutionary framework to explain the maintenance of signal variation in this species. Laboratory experiments were used to explore the effect of intraspecific and interspeci

Herbivory by leaf miners in response to experimental shading of a native crucifer - S. K. Collinge; S. M. Louda (Oecologia, 1988)

Observations of Silver Iodide Plumes over the Grand Mesa of Colorado - Edmond W. Holroyd; Jack T. McPartland; Arlin B. Super (Journal of Applied Meteorology, 1988)
A series of wintertime airborne tracing experiments was examined to determine some characteristics of the plumes of silver iodide smoke released either from the ground or from an aircraft over the Grand Mesa of Colorado. The plumes were identified in nearly every experiment by detecting the airborne AgI particles and often also by observing resulting ice particle plumes in essentially the same airspace. The lateral and vertical plume positions of Wound-released AgI from eight sites were determined for several wind, cloudiness and stability conditions. The instantaneous ground-released plume had a median spreading angle of 15° and meandered within a median angle of 38°. The median plume height above the crest exceeded 500 m. The lateral spreading rates of aircraft-released AgI were estimated at over 2 m s−1 for cloudy conditions and less in clear conditions. The implications for future cloud seeding strategies are discussed.

Evolution of Life Histories: Theory and Patterns from Mammals - A. T. Smith (1988)

Functional Testing of Aquatic Biota for Estimating Hazards of Chemicals - J. Cairns; J. R. Pratt (1988)

Rates of nectar feeding in butterflies: effects of sex, size, age, and sugar concentration - C. L. Boggs (Functional Ecology, 1988)
Rates of ingestion of sucrose varied with sucrose concentration and butterfly sex, age and size for Speyeria mormonia Edwards (Lepidoptera: Nymphalidae). Peak rates of ingestion occurred between sucrose concentrations of 30% and 40%, as predicted by previous theory. Males fed at a faster rate than did females under most experimental conditions. Rates were also high for medium to large individuals as opposed to small individuals. Ingestion rates decreased with age for males but not for females. These results are compared with data available for other species and considered in the context of information on nectar concentrations and composition in the field and activity budgets for S. mormonia. Finally, the possible impact on plant-pollinator interactions is evaluated. Key-words: Foraging ecology, nectar feeding, Speyeria mormonia, pollination ecology, Lepidoptera

The distribution of understory plant species within Populus tremuloides communities - J. Debner (1988)

Why do Ephemerella nymphs scorpion posture: a "ghost of predation past"? - B. L. Peckarsky; M. A. Penton (Oikos, 1988)
The behavior of intact Ephemerella infrequens (Ephemeroptera, Ephemerellidae) and Ephemerella with cerci amputated was observed in response to encounters with live predaceous stoneflies (Megarcys signata, Plecoptera: Perlodidae), tethered-live and tethered-model predators, freshly excised stonefly antennae, and thin wires. The incidences of defensive posturing (scorpion posture), movement (crawl, swim, drift) and freezing (no response, stop) behavior were video-taped in response to these predatory stimuli. Scorpion postures occurred with significantly higher frequency when Ephemerella was touched by live and model Megarcys than by Megarcys antennae and wires, with no differences between the two former or the two latter treatments. Frequency of posturing was not altered by prey orientation toward or away from predators or by direction of predator approach with respect to current (upstream, downstream, or beside prey). Thus, hydrodynamic cues associated with live and model Megarcys rathe

The Grizzly Bear Mine Ouray County, Colorado - Tom Rosemeyer (Rocks & Minerals, 1987)
Click to increase image sizeClick to decrease image size Additional informationNotes on contributorsTom RosemeyerTom Rosemeyer is the owner of Red Mountain Exploration and has mined and collected minerals in the San Juan Mountains for the last twenty years.

Evolutionary Biology of Orthopteroid Insects - R. L. Willey (1987)

The Evolution of Sex and Its Consequences - P. Bierzychudek; P. Bierzychudek (1987)

Allelic isozymes as probes of the evolution of metabolic organization - W. B. Watt; C. L. Boggs (Isozymes, 1987)