The effect of surface area to volume ratios on predation between the predator Mesostoma and the prey Daphnia - M. Arts (1979)

A survey of benthic species diversity along Coal Creek - C. Chang (1979)

Observations of the water strider in the lower kettle pond - K. Cook (1979)

Observation of an aquatic organism (Dytiscid larvae) - S. Goodwin (1979)

Damselflies - a predator preference study - S. Goodwin (1979)

Determination of metal concentrations - G. P. Lockett (1979)

Factors influencing predation on corixids - L. Maxwell (1979)

Site quality of beaver - M. Mueller (1979)

Striking terror into ostracod hearts: feeding and other behaviors of adult Hydracarina in the kettle ponds - R. Raczkowski (1979)

Altitudinal variation of metabolic rates in Peromyscus maniculatus - R. E. Sears (1979)

The anatomy of a beaver dam - C. L. Willard (1979)

The role of chemotactile stimuli in the oviposition preferences of Colias butterflies - M. L. Stanton (Oecologia, 1979)
It is stressed that chemotactile cues are involved only in the final step of oviposition, and that understanding foodplant choice in nature will require in-depth investigation into the mechanics of individual search processes.

Optimal foraging: a case for random movement - Marian A. Zimmerman (Oecologia, 1979)
It is shown that B. flavifrons is using the resource distribution to direct its movements, and a large percentage of all movements are to nearest neighbors with maximal foraging efficiency gained through minimization of flight distances.

Primary productivity of ponds - K. Cook; C. King; M. Mueller; R. Raczkowski (1979)

The distribution of genetic variation in a social mammal, the yellow-bellied marmot - O. A. Schwartz (1979)

The effect of temperature on the activity of fairy shrimp - A. Hamilton (1979)

Genetics of hemoglobin in the deer mouse, Peromyscus maniculatus. I. Multiple alpha and betaglobin structural loci - L. R. G. Snyder (Genetics, 1978)

Actitis macularia - an ethogram, i.e. the spotted sandpiper - how it passes the time while incubating - Matthew Miller (1978)

Competition and cooperation in plant/pollinator systems - J. D. Thomson (1978)

Reproductive strategies in the butterflies. I. Mating frequency, plugging, and egg number - A. H. Ehrlich; A. H. Ehrlich (Journal of the Kansas Entomological Society, 1978)

A short study of selected feeding behaviors in Ambystoma tigrinum - W. C. Curtiss (1978)

An analysis of the effects of the Keystone Mine effluent on the benthic invertebrates in Coal Creek, Gunnison County, Colorado - R. Fabrikant; Matthew Miller (1978)

The damselfly Enallagma boreale: an ethogram - E. Gontero (1978)

Sedimentology and stratigraphy of the Triassic Chinle Formation, eastern San Juan Basin, New Mexico - Dennis D. Kurtz (Rice University's digital scholarship archive (Rice University), 1978)
Upper Triassic continental ëtrata of the Chinle Formation, in the Nacimiento Mountains, New Mexico, represent two cycles of fluvial to fluvial-deltaic to marshland-lacustrine sedimentation. Each cycle was initiated by uplift in the southern Ancestral Rocky Mountains and deposited on the local palaeoslope. However, the influence of this highland on sediment transport and supply diminished with time. Depositional trends exhibited up-section are: 1) fluvial regime changed from a high energy braided stream to a very low energy meandering stream system; 2) palaeotransport directions shifted from southwestwardly to north-northwestwardly; 3) the initial crystalline and metasedimentary source terrain was gradually replaced by a widespread sedimentary one; and 4) mean and maximum grain size decreased. Decreases in fluvatile energy and grain size upwards reflect the lowering of uplands by erosion and the evolution of a continental drainage system on a gentle gradient. Also, the uplift which generated the lower fluvial sequence probably had a steeper initial palaeoslope and was of greater magnitude than the second uplift. Shifts in palaeotransport and provenance are not due to active tectonism, but rather, are a passive response to the waning influence of local highlands on regional sedimentation patterns. The locations and distributions of sedimentary copper deposits, found in the fluvial channel sequences of Chinle sandstones, are chiefly dependent upon the shape and porosity of the channel deposits,and the amount of organic matter that was present to reduce copper-bearing fluids. Porosity of these channels, as it affects copper mineralization is controlled by the amount and' time of formation of calcareous cement.

Growth rates and size at metamorphosis of high elevation populations of Ambystoma tigrinum - J. R. Bizer (Oecologia, 1978)
The claim that temperature, rather than food abundance, determines the alternative life history sequences followed by high elevation populations of A. tigrinum is substantiated.

The population dynamics of aphids on fireweed: a comparison of local populations and metapopulations - J. F. Addicott (Canadian Journal of Zoology, 1978)

Niche relationships among species of aphids feeding on fireweed - J. F. Addicott (Canadian Journal of Zoology, 1978)
Three species of aphids in the genus Aphis and one in the genus Macrosiphum feed on fireweed in the Rocky Mountains of Colorado, U.S.A. These species differ in their time of colonization of fireweed, time of maximum number of colonies, feeding position on fireweed, relationships to tending ants, life table parameters, and other life history characteristics. Possible reasons for such differences among cooccurring aphids are discussed.

Physical limnology: an analysis of the upper kettle pond - B. Shmaefsky (1978)

Diet of brook trout (Salvelinus fontinalis Mitchill) and brown trout (Salmo trutta L.) in an alpine stream - J. D. Allan (Verhandlungen der Internationale Vereinigung fr Theoretische und Angewandte Limnologie, 1978)

Allometry and jumping in frogs: helping the twain to meet - S. B. Emerson (Evolution, 1978)

Some factors influencing size of Diaptomus shoshone - E. J. Maly (Limnology and Oceanography, 1978)

Genetics of hemoglobin in the deer mouse, Peromyscus maniculatus. II. Multiple alleles at regulatory loci - L. R. G. Snyder (Genetics, 1978)

The response (or lack of it) of Kugotus modestus to a competitor and prey - R. Fabrikant (1978)

Introduction of leaf packets into the East River - a preliminary study - B. Shmaefsky (1978)

The effect of an altitudinal gradient on stream insects of Copper Creek, or benthic bugs - E. Gontero (1978)

Observational study on the tricopteran larvae (Family Limnephilidae) with special reference to distribution among habitats - M. Arts (1978)

Observations of trout in beaver ponds near Copper Creek - M. G. Gale (1978)

The Ecological Distribution of Cholla Cactus (Opuntia imbricata (Haw.) DC.) in El Paso County, Colorado - Thomas B. Kinraide (The Southwestern Naturalist, 1978)
The range of Opuntia imbricata (Haw.) DC., together with data from 250 weather stations, was mapped revealing that the cactus is essentially confined to a region receiving 28 to 48 cm annual precipitation and experiencing mean January temperatures above --1'C. The distribution of the cactus was quan- titatively mapped for El Paso County, Colorado, the northernmost county of its range. Here the cactus achieves greater densities upon soils of high clay content and upon areas of sloping and concave surface and southern aspect. An analysis of published data from New Mexico reveals a greater abundance of cholla upon fine textured soils in that state as well. Individual plants are dispersed according to a Poisson distribution-at least within quadrats 4 to 100 m2 in area. Within 25 m2 quadrats the cactus asociated positively, and significantly, with Sitanion hystrix, Hilaria famesii, Muhlenbergia torreyi, and Yucca glauca. Negative associations were observed with nine species, most of which are commonly regarded as weeds or indicators of range deteriora- tion. The quadrats were objectively segregated into several groups, and the species composition of each group has been tabulated. The successional status of Opuntia imbricata has not been established, nor has its status as a pasture pest been determined.

Geographical distribution and biological observation of Cyphoderris (Orthoptera: Haglidae) with a description of a new species - G. K. Morris; D. T. Gwynne (Psyche, 1978)

Human Skeletal Remains from Bradford House III, Site 5JF52, Jefferson County, Colorado - Michael Finnegan (Plains Anthropologist, 1978)
The skeletal remains of an adult male individual from the 5JF52 site was analyzed to the extent allowed by the condition of the bony skeleton. The analysis includes a description of the material, dentition, demographic information pertinent to age, sex, stature and race, and a complete analysis of metric and non-metric variation. A Stafne defect was found on the inferior margin of the mandible which is analyzed relative to other Archaic material. In addition, pathology is noted mostly in the vertebral column and anomalous cervical ribs were found on the seventh cervical vertebra with an associated display of disuse atrophy of the left humerus. The material was also x-rayed in order to supplement a growth inspection of this skeletal material. The results of the skeletal analysis compare favorably with other single male individuals from the same or near regions covering the same Archaic time period. Analysis of this skeletal material generally expands our knowledge of pathology and anomalies on Archaic material from Colorado.

Colorado Green River Formation oil shale as viewed by pulsed n.m.r. - R. SYDANSK (Fuel, 1978)

Interspecific pollen transfer and competition between co-occurring plant species - Nickolas M. Waser (Oecologia, 1978)
Results from simulations suggest that competition for pollination through interspecific pollen transfer can result in rapid exclusion of one of two species, and that such competition represents a selective force promoting stable divergence of potential competitors in habitat affinity, flowering time, or other characteristics related to pollinator sharing.

Sex differences in the play behavior of yearling yellow-bellied marmots - S. H. Jamieson (1978)

Behavioral ecology of alpine yellow-bellied marmots - D. W. Johns (1978)

Trout predation and the size composition of stream drift - J. D. Allan (Limnology and Oceanography, 1978)
Nocturnal drift of stream invertebrates is examined as a predator avoidance adaptation via the hypothesis that those taxa or growth stages which are large, and thus subject to intense predation relative to smaller forms, should be most strongly constrained to nocturnal drift activity. Smaller taxa or stages may be aperiodic or day active. Data from an alpine stream document for the abundant and widespread mayfly Baetis bicaudatus that, on a continuum from small to large size, the risk of predation increases while the propensity to drift during the day decreases. There is supporting and some contrary evidence from the literature for the generality of this pattern.

Dippers (Cinclus mexicanus unicolor): an ethogram - R. Fabrikant (1978)

Competition for mutualists: aphids and ants - J. F. Addicott (Canadian Journal of Zoology, 1978)
Evidence is presented which supports the hypothesis that competition occurs among species of aphids for the services of ants. It is suggested that, in addition to the more familiar pollination systems, aphid–ant systems should be used for the study of competition for mutualists because aphid–ant systems have both a significant advantage and important differences with respect to pollination systems.

The pollination ecology of Aquilegia elegantula and A. caerulea (Ranunculaceae) in Colorado - R. B. Miller (American Journal of Botany, 1978)
Aquilegia elegantula Greene and A. caerulea James occur in montane and subalpine habitats in the southern Rocky Mountains of western North America. The red and yellow flowers of A. elegantula are nodding, odorless, protogynous, and secrete a concentrated (44%) sucrose nectar in the floral spurs. Seed set in flowers under pollinator exclosures was 12% while seed set in open‐pollinated flowers was 65%. The flowers of A. elegantula are pollinated primarily by the Broad‐tailed Hummingbird (Selasphorus platycercus [Swainson]) and by at least three species of pollen‐foraging bumblebees, of which Bombus occidentalis Greene is the most common. The blue and white flowers of A. caerulea are erect, mildly fragrant, protandrous, and secrete a 26% sucrose nectar. Seed set in caged flowers in the field averaged 39%. in uncaged flowers 54%. The most important pollinators of A. caerulea are the crepuscular hawkmoth, Hyles (=Celerio) lineata (Fabricius) and ten species of pollen‐foraging Bombus. The most abundant bumblebee species, B. occidentalis, is also a frequent nectar thief. Differences in pollination systems alone probably do not constitute an effective anti‐hydridization mechanism between A. elegantula and A. caerulea, but do serve to reinforce differences in habitat and flowering time that distinguish the two species.

Optimal foraging: movement patterns of bumblebees between inflorescences - G. H. Pyke (Theoretical Population Biology, 1978)
Nectar-collecting bumblebees are hypothesized to employ rules of movement which result in the maximum net rate of energy gain (i.e., are optimal), and predicted patterns of movement are compared with field observations to support the hypothesis.

Geology of the Urad and Henderson molybdenite deposits, Clear Creek County, Colorado, with a section on a comparison of these deposits with those at Climax, Colorado - S. R. Wallace; W. B. MacKenzie; R. G. Blair; N. K. Muncaster (Economic Geology, 1978)
The Urad and Henderson stockwork molybdenite orebodies at Red Mountain, Clear Creek County, Colorado, are related to a rhyolitic subvolcanic center of Oligocene age referred to as the Red Mountain Complex. The two orebodies are well separated in space and are specifically related to different intrusive rocks of the complex. The Urad orebody was deposited first and at shallow depth. The Henderson formed deeper within the complex and is much the larger of the two. The Oligocene rocks intrude a batholith of Precambrian Silver Plume Granite near the western edge of the Colorado mineral belt and are within a mile of the north-north-east-trending Berthoud Pass fault. This fault is the major structural element of the area and has been identified by Tweto and Sims (1963) as a Precambrian fault reactivated in Tertiary time.The part of the Red Mountain Complex crops out over an irregular area about 2,400 feet long and 800 to 1,200 feet wide. Dikes related to the complex surround it and are present as much as 1 mile from the igneous center. Known rocks of the complex represent more than 15 stages and substages of igneous activity. All rocks are chemically and mineralogically similar and consist of essential quartz, K-feldspar, albite, and minor biotite. Clastic and fragmental textures are common features of the rocks exposed at surface, porphyries predominate at intermediate depths, and a granitic rock is present at the greatest depths reached in exploratory drilling. The major rock types of the complex exposed at the surface are columns that either grade into, or are cut off by, an underlying composite stock, the apex of which lies about 2,500 feet below the peak of Red Mountain. The stock, although much larger than the shallower columns, appears to be a steep-walled intrusive to explored depths. The space now occupied by the stock is thought to have been a magma chamber throughout the time the rocks exposed at the surface were emplaced; the magma chamber was their immediate source. The sequence of rocks exposed at surface is as follows: Tungsten Slide and East Knob units (relative ages unknown), Square quartz porphyry, rhyolite porphyry radial dikes, and the Red Mountain porphyry unit. Each unit consists of several members. Rock types which constitute the buried stock are, from oldest to youngest, the Urad porphyry, the Primos porphyry, and the Henderson granite. The Square quartz porphyry is the youngest known igneous rock predating the Urad orebody and is considered to have been the source intrusive for the Urad mineralized zone of which the Urad orebody is a part. The Urad mineralized zone is envisioned as a cylindrical body of mineralized rock. The orebody was localized within part of this zone by a series of moderately dipping arcuate fractures referred to as the main fissure system. The fissures are interpreted as cone sheet fractures caused by the emplacement of the Square quartz porphyry. About half of the orebody was contained in rocks of the Red Mountain Complex; the rest was in the Silver Plume Granite. The Urad mine, now worked out, produced about 14 million tons of ore. Intrusion of the Red Mountain porphyry, the principal rock of the complex at surface, destroyed much of the Square quartz porphyry, a large part of the Urad mineralized zone, and part of the Urad orebody. The magma from which the Red Mountain porphyry crystallized probably vented; a potential orebody may have been lost to the atmosphere during this event.The Henderson orebody is an umbrella-shaped stockwork entirely within the intrusive complex and contains more than 300 million tons of ore. The difference in the shape of the Urad mineralized zone and the Henderson orebody is thought to reflect the difference in the depth of formation. The Henderson deposit is genetically related to one or more phases of the Primos porphyry and to the Henderson granite and is a compound orebody. A master reservoir is postulated at depth beneath Red Mountain to explain the repetition of igneous and hydrothermal events and to provide the quantity of metal necessary for the formation of the ores. We believe that this magma derived its ore metal from crustal rocks anomalously rich in molybdenum during its rise toward the surface. The deposits at Red Mountain are remarkably similar in many respects to those at Climax, Colorado, but there are some notable differences. The abundance of Precambrian metamorphic rocks, possibly available for reaction with, or incorporation by, Oligocene magma at Climax, and the scarcity of these rocks at Red Mountain may account for the large amount of tungsten in the Climax deposit compared to that in the Urad and Henderson orebodies.

Optimal foraging in bumblebees and coevolution with their plants - G. H. Pyke (Oecologia, 1978)
The pattern of movements of the bumblebees and the various properties of the plants appear to represent coevolved adaptations and the bumbles' movement patterns appear to be optimal in the sense that they result in the maximum net rate of energy gain to the bumbling.

Energetics of yellow-bellied marmot populations - D. L. Kilgore; Kenneth B. Armitage (Ecology, 1978)
The energy dynamics of 2 colonies of yellow—bellied marmots (Marmota flaviventris) were studied in the Rocky Mountains of central Colorado in 1969 and 1970. The Intake—Rejecta and Maintenance—Production models, which included an analysis of seasonal variations in energy flow parameters, yielded similar estimates of population energy flow. Colony energy flow ranged from 64.0 to 94.6 KJ°m(—2)°yr(—1). Differences between colonies in annual energy flow can be explained by variations in biomass. Peak energy flow occurred at different times in the 2 colonies and the timing was related to reproductive conditions. The marmot populations consumed 94.6 to 119.2 kJ°m(—2)°yr(—1), which represented 0.8 to 3.1% of the aboveground primary production. The efficiency with which the marmot populations exploited the available net primary production was 2 to 6.4%. Seventy—one to 75% of the energy ingested by the populations was assimilated; only 77% of the assimilated energy went into maintenance of the population biomass. Tissue growth efficiency averaged 16.8%, °5x greater than typical homeotherms. The production/maintenance ratio averaged 29.6%. The marked differences in the respiration efficiencies, tissue growth efficiencies, and production: maintenance ratios between the heterothermic marmot and typical homeotherms suggest that heterothermy represents a distinct strategy in secondary production.

A physical study of Sylvanite Lake - M. G. Gale (1978)

Optimal foraging in hummingbirds: testing the marginal value theorem - G. H. Pyke (American Zoologist, 1978)
To a hummingbird, clusters of flowers on inflorescences represent patches and provide an ideal situation to test prediction of optimal patch-use. The basic question is what decision rule should a hummingbird use to decide whether or not to leave an inflorescence? The hypothesis is that hummingbirds will adopt the decision rule that maximizes their net rate of energy gain while foraging. This hypothesis leads to an analogue of Charnov's marginal value theorem which determines an optimal decision rule. The optimal decision ruleis then used to predict aspects of the hummingbirds' foraging, and these predictions are compared with field data The optimal decision rule is a function of how much information is used by the hummingbirds. Data indicate that a decision to leave an inflorescence is a function of the number of flowers visited, the number of flowers available on the inflorescence, and the amount of nectar obtained at the last flower. The optimal decision rule was calculated assuming no additional information is used.

Competition for hummingbird pollination and sequential flowering in two Colorado wildflowers - Nickolas M. Waser (Ecology, 1978)
The simultaneous flowering of co—occurring plant species with similar pollinator affinities may result in interspecific pollen transfer and consequent fecundity reductions due to wastage of pollen, stigma surfaces, and effective pollinator visits. In such cases competition for pollination occurs and may lead to or maintain sequential flowering. Two common perennials in the mountains of west—central Colorado, Delphinium nelsoni and Ipomopsis aggregata, flower sequentially in the same meadows and are visited commonly by Broad—tailed Hummingbirds (Selasphorus platycercus). Hummingbirds carry pollen of both species and their exclusion from flowers leads to significant seed set reductions. During the brief period of flowering overlap between D. nelsoni and I. aggregata in natural meadows, hummingbirds visit both species, carry mixtures of their pollen, and appear to cause interspecific pollen transfer. Flowers of both species receptive during this period suffer significant seed set reductions relative to those receptive during nonoverlap periods. Interspecific pollinator flights and pollen transfer also occur in mixtures of potted plants, and seed set reductions consistently occur for both D. nelsoni and I. aggregata in such mixtures relative to single—species controls. Finally, seed set reductions occur for both species following interspecific hand pollination of potted plants. Fecundity reductions in natural and synthetic mixtures of D. nelsoni and I. aggregata indicate that the 2 species compete for hummingbird pollination and suggest that the competitive interaction involves interspecific pollen transfer. The observed reproductive effects represent a selective force sufficient to maintain divergent flowering times of D. nelsoni and I. aggregata in nature.

Life history patterns of Ambystoma tigrinum in montane Colorado - O. J. Sexton; J. R. Bizer (American Midland Naturalist, 1978)
A survey of approximately 60 ponds in the Gunnison Basin, Gunnison and Pitkin counties, Colorado, U.S.A., showed a cor- relation between the thermal ranges of the ponds and the life history pattern of Ambystoma tigrinum populations. Characterization of physical and biotic parameters allowed a ranking of ponds from warm to cool, verified by temperature data taken through two warm seasons (1974 and 1975). The life history pattern of the salamander populations was deter- mined on the basis of the number of size classes of salamanders observed in the pond. A model is proposed relating the thermal regimes of the pond and the observed life history pattern of the salamanders. Three life history patterns are defined for these populations: standard life his- tory, only one size class of larvae; neotenic life history, two size classes of larvae with metamorphosis occurring in the second warm season; and neotenic and paedogenic life histories, three or four size classes of larvae with metamorphosis occurring the the third or later warm season.

Factors affecting body temperatures of toads - C. Carey (Oecologia, 1978)
Factors influencing levels and rates of variation of body temperature (Tb) in montane Bufo boreas boreas and in lowland Bufe boreas halophilus were investigated as an initial step toward understanding the role of natural thermal variation in the physiology and energetics of these ectothermic animals.

Resource partitioning in bumblebees: experimental studies of foraging behavior - David W. Inouye (Ecology, 1978)
A system comprising 2 species of bumblebess (Bombus appositus and Bombus flavifrons) and 2 species of flowers (Delphinium barbeyi and Aconitum columbianum) in Gothic, Colorado, USA, was manipulated to determine whether resource utilization by each bumblebee species was influenced by the presence of the other species of bumblebee. Each bumblebee species concentrated its foraging efforts on a different flower species, apparently choosing the species whose corolla tube length matched its proboscis length most closely. When each bumblebee species was temporarily removed from its preferred flower species, the remaining bumblebee species increased visitation to the other, previously less—utilized, flower species. The remaining bumblebees visited more flowers per stay in the patch, suggesting that they were finding greater amounts of nectar in the absence of other bumblebee species. These removal experiments demonstrated that the bumblebees were sampling flowers frequently enough and were flexible enough in their foraging behavior to respond rapidly to short—term changes in nectar availability. In another area, where its preferred flower species and the other bumblebee species were absent, B. flavifrons foraged actively on the flower species it rarely used in Gothic. This observation and the experiments demonstrate that resource utilization by a bumblebee species is influenced by the presence of other species and suggest that the phenomenon of competitive release can be observed in bumblebees. In this system,interspecific exploitation competition appears to be the primary mechanism involved in resource partitioning.

Water strider behavior in the lower kettle pond - B. Shmaefsky (1978)

The Role of Arthropods in Forest Ecosystems - David W. Inouye (1977)

Reduction of pore area of the avian eggshell as an adaptation to altitude - H. Rahn; C. Carey; K. Balmas; B. Bhatia; C. Paganelli (Proceedings of the National Academy of Sciences, 1977)
Standard measurements of water vapor conductance in units of mg of H 2 O · day -1 · torr -1 (SI equivalent is mg of H 2 O · day -1 · pascal -1 ) of fresh eggs of the red-winged blackbird ( Agelaius phoeniceus ) and the native chicken of India ( Gallus gallus ) collected at altitude are significantly less than those of eggs of the same species collected near sea level. This decrease is caused by a reduction of the total effective pore area of the eggshell at altitude. It appears to be proportional to the reduction in barometric pressure and the simultaneous increase in the diffusion coefficient of water vapor. Thus, reduction in pore area offsets increased diffusivity at altitude, and water vapor loss through the eggshell at any altitude remains the same as at sea level. The data suggest a structural adaptation of the shell to altered diffusivity of gases at altitude in order to prevent excessive water loss of eggs during natural incubation.

Flower behavior in Linum lewisii: some ecological and physiological factors in opening and abscission of petals - F. T. Addicott (American Midland Naturalist, 1977)
Fredrick T. Addicott, Flower Behavior in Linum lewisii: Some Ecological and Physiological Factors in Opening and Abscission of Petals, The American Midland Naturalist, Vol. 97, No. 2 (Apr., 1977), pp. 321-332

Adaptation at specific loci. I. Natural selection on phosphoglucose isomerase of Colias butterflies: biochemical and population aspects - W. B. Watt (Genetics, 1977)
ABSTRACT Electrophoretic variants of phosphoglucose isomerase (PGI) in Colias butterflies have been studied from field and laboratory viewpoints. The transmission pattern is that of a dimeric enzyme controlled by one structural gene locus. Populations usually harbor four to six allelic mobility classes. These mobility classes are shared among species complexes, though their frequencies differ widely. Preliminary Ferguson plot analysis of the variants has been carried out. Purified preparations of Colias PGI alleles are more effective in standardizing Ferguson plots than heterologous proteins, such as ferritin. Variation of Ferguson plot parameters is not an infallible guide to electrophoretically "cryptic alleles," as one putative case proved to be due to nonallele-specific effects. S, M, and F mobility classes in two Colias semispecies show the same retardation coefficients in Ferguson plots. Adults early in the flight periods of their nonoverlapping generations show genotype frequencies in Hardy-Weinberg equilibrium, but heterozygote excess develops as the insects age. Simple directional selection and large-scale population mixing are unlikely to be causes of this, although several other selection modes remain possible. Identical-by-descent lines of the four frequent-to-common alleles in C. eurytheme have been set up in culture, and enzyme has been purified from these for study of functional properties. Major differenecs in heat stability and in various kinetic parameters are found among the ten possible genotypes. In some cases, heterosis for kinetic parameters is seen; in other cases, opposing trends in kinetic function and heat stability create potential for net heterosis in function. Possible interpretations of these results in an adaptive metabolic context are discussed, and directions for further work are stated.

The food habits of stoneflies (Plecoptera) in the upper Gunnison River, Colorado - R. L. Fuller; K. W. Stewart (Environmental Entomology, 1977)
Gut contents of 1,463 stonefly nymphs, comprising 10 species, from the Gunnison River, Colorado, were analyzed from Dec., 1974–Oct., 1975, in relation to food availability. Pteronarcella badia fed primarily on detritus and moss. Perlidae and Perlodidae mature nymphs were all carnivorous, but showed considerable seasonal-developmental shifting in diets and preference during earlier stages. Early instar Isoperla fulva nymphs were herbivore-detritivores, then gradually shifted through an omnivorous to carnivorous diet as development proceeded. Claassenia sabulosa and Hesperoperla pacifica remained carnivorous throughout development. Dominant prey groups were chironomids, mayflies and caddisflies. Horn's Coefficient of Dietary Overlap showed significance among all predator species for major food categories, but subtle mechanisms such as prey species-and size-selectivity and temporal succession provided sufficient partitioning of the abundant food resources to allow for coexistence. Large Claassenia sabulosa nymphs in August selected more mayflies after dark than in the afternoon. No behavioral selection by predacious stoneflies was indicated for the chironomids Ablabesmyia sp., Cricotopus sp., Prodiamesa sp., and Rheotanytarsus sp.

Competition for pollination and the evolution of flowering time - Nickolas M. Waser (1977)

Implications of recaptures of broad-tailed hummingbirds banded in Colorado - Nickolas M. Waser; David W. Inouye (Auk, 1977)

Tree selection and utilization by Castor canadensis - C. Fogler (1977)

Behavioral notes on a single beaver family - J. Marvin (1977)

Implications of recaptures of broad-tailed hummingbirds banded in Colorado - Nickolas M. Waser; David W. Inouye; David W. Inouye; Nickolas M. Waser (Auk, 1977)

A study of species' home range, population, and habitat affinities plus a diversity comparison of different habitat types - D. Moron (1977)

Activity and feeding behavior of the least chipmunk, Eutamias minimus, near Gothic, Colorado - C. F. Williams (1977)

Competition in plant-pollinator systems: An analysis of meadow communities in the Colorado Rocky Mountains - J. Pleasants (1977)

Competition in plant-pollinator systems: an analysis of meadow communities in the Colorado Rocky Mountains - J. Pleasants (1977)

Collection of ectoparasites of small mammals - a methodology - P. G. Rieck (1977)

Coevolution of pierid butterflies and their cruciferous foodplants. II. The distribution of eggs on potential foodplants - F. S. Chew (Evolution, 1977)
The extreme specificity

Shrew populations in 3 habitat types near Gothic, Colorado - S. D. Strahl (1977)

Social variety in the yellow-bellied marmot: a population-behavioural system - Kenneth B. Armitage (Animal Behaviour, 1977)
This is the publisher's version of the paper's abstract, which can be found at: http://www.sciencedirect.com/science/article/pii/0003347277901087.

A comparative study of mammalian faunal diversity and density in aspen versus meadow habitat or if you want a mouse, don't climb a tree - E. D. Cleveland (1977)

Life history phenomena of Ambystoma tigrinum in montane Colorado - J. R. Bizer (1977)

Mule deer usage of a natural saltlick - C. A. Peed (1977)

The effects of kidney structure and the annual cycle on water requirements in golden-mantled ground squirrels and chipmunks - B. H. Blake (Comparative Biochemistry and Physiology, 1977)
Minimum water requirements of non-torpid golden-mantled ground squirrels and chipmunks and Eutamias change throughout the annual cycle from a high in the reproductive season to a low in the hibernating season.

Chickaree middens as foraging sites for Clethrionomys gapperi - M. Nelson (1977)

Population structure of pierid butterflies. I. Numbers and movements of some montane Colias species - A. G. Watt; F. S. Chew; L. R. G. Snyder; A. G. Watt; D. E. Rothschild (Oecologia, 1977)

Colorado plant materials : long range plan - United States. (1977)
A comparatively new kind of plant materials challenge has entered the picture in Colorado in recent years. This is revegetation at high elevations.

Predation by badger on yellow-bellied marmot in Colorado - D. C. Andersen; D. W. Johns (Southwestern Naturalist, 1977)

Food selection in pikas (Ochotona princeps) - M. Welton (1977)

Activity and feeding of Spermophilus lateralis - H. Young (1977)

Population densities and ecological preferences of rodents in a meadow near Gothic, Colorado - R. H. Melton (1977)

Morphological variation in North American pine grosbeaks - C. S. Adkisson (Wilson Bulletin, 1977)

Resource partitioning in bumblebees - David W. Inouye (Journal of the New York Entomological Society, 1977)

Sedimentology of braided alluvial interval of Dakota Sandstone, northeastern New Mexico - J. L. Gilbert; George B. Asquith (1976)
The Dakota Sandstone (Cretaceous) in northeastern New Mexico is subdivided i to 3 intervals (Jacka and Brand, 1973). The lower interval is a braided al luvial sheet composed of fine- to medium-grained, cross-stratified sandstone with conglomerate lenses. The middle interval represents a meander -belt environment and contains fine- to ery fine grained, lenticular sandstone with interbedded carbonaceous shal e and coal. The upper interval represents a transgressive marine succession containing fine - to very fine grained, horizontally stratified sandstone with burrow casts of Ophiomorpha. Paleocurrent analysis of the braided alluvial interval indicates a domina nt southeasterly transport direction. This conclusion is supported by a decrease in mean grain size and thickness to the east and southeast. Analysis of the stratification ratio indicates that proximal braided -stream facies are predominant in the west and northwest parts of the study area, and that distal braided -stream facies are predominant to the east and southeast. The sediment dispersal pattern and the presence of proximal braided stream facies indicate that the source areas were the San Luis and Apish apa uplifts of Colorado and N w Mexico.

Respiratory responses to hypoxia by Ambystoma tigrinum larvae, paedomorphs, and metamorphosed adults - A. G. Heath (Comparative Biochemistry and Physiology, 1976)

A study of two populations of Erysimum - D. Phillips (1976)

Scent-marking by yellow-bellied marmots - Kenneth B. Armitage (Journal of Mammalogy, 1976)

Energetics of small body size and high latitude: the rufous humming bird in Coastal Alaska - W. A. Calder (International Journal of Biometearology, 1976)

The structure and genetics of a montane population of the checkerspot butterfly, Chlosyne palla - R. D. Schrier; M. J. Cullenward; P. R. Ehrlich; R. R. White (Oecologia, 1976)

Polymorphisms for hemoglobin and 6-phosphogluconate dehydrogenase in the rodent genus, Peromyscus - L. R. G. Snyder (1976)

Polymorphisms at regulatory loci: quantitative inheritance of hemoglobin phenotypes in the deer mouse, Peromyscus maniculatus - L. R. G. Snyder (Genetics, 1976)

Permeability of trout erythrocytes to nonelectrolytes - F. R. Hunter (Biological Bulletin, 1976)
Using a densimeter technique, a kinetic analysis was made, employing both entrance and exit studies, of the permeability of erythrocytes of brook trout (Salvelinus fontinalis), rainbow trout (Salmo gairdneri), German brown trout (Salmo trutta) and cutthroat trout (Salmo clarki) to glycerol, ethylene glycol, thiourea and urea. All of the data indicate that these four nonelectrolytes cross the membrane of the erythrocytes of these four species of fishes by simple diffusion only.

Facilitated diffusion in erythrocytes of additional mammals - F. R. Hunter (Comparative Biochemistry and Physiology, 1976)
The kinetics of both swelling and shrinking of erythrocytes of the yellow-bellied marmot, golden-mantled ground squirrel, chipmunk, deer mouse, long-tailed vole, montane vole and western jumping mouse indicate that glycerol, ethylene glycol, urea and thiourea penetrate by means of facilitated diffusion.

Biologically Significant Areas in Gunnison County Colorado - R. L. Willey (1976)

Distribution and population differences of Ophrydium versatile (a ciliated protozoan) - R. Walkosz (1976)

High altitude studies of natural, supplemental and deletion of UV-B on vegetables and wheat : final report / - F. D. Moore; M. R. Becwar; Mardy Burke; BACER Program (U.S.); United States. (1976)
Decisions having great impact must be made with regard to inadvertent modification of the upper stratosphere.

Energy crisis of the hummingbird - W. A. Calder (Natural History, 1976)

Resource overlap between co-occurring copepods: effects of predation and environmental variability - E. J. Maly (Canadian Journal of Zoology, 1976)

Zooplankton: specific distribution and food abundance - S. I. Dodson; C. Edwards; F. Wiman; J. C. Normandin (Limnology and Oceanography, 1976)

Socioecology of marmots: female reproductive strategies - D. C. Andersen; Kenneth B. Armitage; R. S. Hoffman (Ecology, 1976)
The relationship between female reproductive success and both spring food and hibernacula resources was examined in a high—altitude population of yellow—bellied marmots (Marmota flaviventris). The number of offspring a female weaned was significantly associated with the estimated number she could potentially produce, based on food resources. The production of young by these females is probably food limited to varying degrees. Hibernacula may be a restricted resource; young reared in an area without a hibernaculum were not recaptured as yearlings. Delaying pregnancy until forage is available fails as a strategy because young have insufficient time to accumulate fat for hibernation. Adult females deposit fat at a single maximum rate regardless of reproductive history; few females gain weight prior to weaning their young. In areas with short growing seasons, measured as the period during which nonreproductive adults gain weight, females may occasionally or regularly fail to reproduce in consecutive years. The short period of time following weaning may not permit the accumulation of fat sufficient to provide energy for hibernation, postmergence activity, and reproduction. The growth rate (g/day) of young marmots is greater at high than at intermediate elevations. This increase in growth rate warrants further examination of the hypothesis that increased sociality among marmots living in areas with short growing seasons is a response to decreased growth rates of young animals.

Seasonal changes in weights of marmots - Kenneth B. Armitage; J. F. Downhower; G. E. Svendsen (American Midland Naturalist, 1976)
Seasonal changes in the body weights of yellow-bellied marmot (Marmota flaviventris) populations were studied for 8 years in western Colorado. Marmots may be classified by size into four age groups: juvenile, yearling, 2-year-old, and 3-year-old or older, each group with significantly different mean body weights. For each age group, the mean body weight of males was significantly larger than that of females. Mean body weights in June of yearlings and older were smaller, the later the onset of the growing season. All age groups made signifi- cant weight gains each year; there was no significant difference in growth rates among years. When the rates of weight gain of juveniles are corrected for time of appearance aboveground, the regression coefficients are virtually identical. The earlier young marmots are weaned, the more they weigh at hibernation and the more likely they are to survive hibernation. The percentage of young surviving their first winter of hibernation is significantly greater the earlier spring begins. Marmots at 3400 m elevation had growth -rates similar to those of mar- mots at 2900 m elevation. The adaptive strategy of marmots includes rapid growth rates, high tissue growth efficiencies and extension of the growing season by repro- ducing immediately following hibernation.

Vocalizations of the long-tailed weasel (Mustela frenata) - G. E. Svendsen (Journal of Mammalogy, 1976)
Journal Article Vocalizations of the Long-Tailed Weasel (Mustela frenata) Get access Gerald E. Svendsen Gerald E. Svendsen Department of Zoology, Ohio University, Athens, Ohio 45701The Rocky Mountain Biological Laboratory, Gothic-Crested Butte, Colorado 81224 Search for other works by this author on: Oxford Academic Google Scholar Journal of Mammalogy, Volume 57, Issue 2, 20 May 1976, Pages 398–399, https://doi.org/10.2307/1379704 Published: 20 May 1976 Article history Received: 17 September 1974 Accepted: 03 November 1975 Published: 20 May 1976

Caloric content of Rocky Mountain subalpine and Alpine Plants - D. C. Andersen; Kenneth B. Armitage (Journal of Range Management, 1976)
Caloric equivalents for aboveground parts of Rocky Mountain subalpine and alpine herbaceous plants averaged 4,859 cal/g ash-free oven-dry weight. Ash content averaged 9.8% for 17 forbs. Both caloric content and ash content ranged higher than values for alpine species from New Hampshire.

Lumbricid Earthworm Populations in a Colorado Mountain River - J. M. Ward (The Southwestern Naturalist, 1976)

Aspects of circulatory physiology of montane and lowland birds - C. Carey; M. L. Morton (Comparative Biochemistry and Physiology, 1976)
A comparison of blood values of American goldfinches during summer and winter in Michigan reveals an increase in blood characteristics of winter individuals similar in extent to that of winter pine siskins, raising the possibility that the blood parameters of high altitude birds reflect adjustments in oxygen carrying capacity to meet the thermogenic demands as well as hypoxia characterizing cold montane habitats.

A Turquoise-Like Mixture of Chalcedony and Celadonite from Conejos County, Colorado - R. J. Mitchell (Rocks & Minerals, 1976)
"A Turquoise-Like Mixture of Chalcedony and Celadonite from Conejos County, Colorado." Rocks & Minerals, 51(8), pp. 394–395

Non-random orientation of entrance holes to woodpecker nests in aspen trees - David W. Inouye (Condor, 1976)
Journal Article Nonrandom Orientation of Entrance Holes to Woodpecker Nests in Aspen Trees Get access D. W. Inouye D. W. Inouye Department of Zoology, University of North Carolina, Chapel Hill, North Carolina 27614 Search for other works by this author on: Oxford Academic Google Scholar The Condor, Volume 78, Issue 1, 1 January 1976, Pages 101–102, https://doi.org/10.2307/1366924 Published: 01 January 1976 Article history Accepted: 03 July 1974 Published: 01 January 1976

Structure and location of burrows of yellow-bellied marmot - G. E. Svendsen (Southwestern Naturalist, 1976)
The yellow-bellied marmot spends approximately 80% of its life in a burrow. Burrows provide protection from the rigors of the environment, pred- ators and other marmots. They provide a hibernaculum in winter and may func- tion as a nursery in summer. Selection of a burrow site is therefore an important aspect in the biology of marmots. Measurements were made on direction of exposure, angle of slope, drainage, soil type, topographic features, and vegetation. Home burrows occur on open grassy or herb-covered slopes of an angle of 15 -40?, facing in a northeasterly or southwesterly direction, and containing rocks and boulders. The latter support the burrow and serve as sunning and observation sites. Five dissected home-burrows showed no marked differences in general configuration. The yellow-bellied marmot (Marmota flaviventris) is a semi-fos- sorial rodent which spends up to 80% of its life in a burrow. Marmots are seasonally active above ground from early spring to fall (Armitage 1965). During this time they exhibit a bimodal pattern of daily activ- ity which peaks during the morning and again in late afternoon. Marmots retire to the confines of the burrows during mid-day and at night. Subalpine populations of yellow-bellied marmots are character- ized by seasonal activity limited to about five months out of the year. The remainder of the year is spent in hibernation. Hibernation ac- counts for about 60% of the total underground existence of a marmot. In summer, if conditions of the present burrow are not suitable, a mar- mot can move or construct a new burrow. During winter, the marmot is hibernating and there is no way for it to control the environment in which it must survive. Hibernation burrows must be elected prior to onset of adverse environmental conditions and must provide the neces- sary requirements for survival. In summer the burrow also serves as a nursery, a haven from predators, and seclusion from interactions with other marmots. The quality of the burrow site is therefore a criti- cal aspect to be considered in the biology of the marmot. Marmot bur- row sites are usually located in open, herb-covered, talus slopes or grassy meadows in which rock outcrops and boulders are common

Resource partitioning and community structure: A study of bumblebees in the Colorado Rocky Mountains - David W. Inouye (1976)

Green River Formation of Utah and Colorado and playa-lake deposition: Comment - Mounir T. Moussa (Geology, 1976)
Research Article| June 01, 1976 Green River Formation of Utah and Colorado and playa-lake deposition: Comment: Comment Mounir T. Moussa Mounir T. Moussa 1Department of Geology, University of Puerto Rico, Mayaguez, Puerto Rico 00708 Search for other works by this author on: GSW Google Scholar Author and Article Information Mounir T. Moussa 1Department of Geology, University of Puerto Rico, Mayaguez, Puerto Rico 00708 Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1976) 4 (6): 326–382. https://doi.org/10.1130/0091-7613(1976)4<326:GRFOUA>2.0.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Mounir T. Moussa; Green River Formation of Utah and Colorado and playa-lake deposition: Comment: Comment. Geology 1976;; 4 (6): 326–382. doi: https://doi.org/10.1130/0091-7613(1976)4<326:GRFOUA>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract No Abstract Available. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Moisture Relationships in Twelve Northern Desert Shrub Communities Near Grand Junction, Colorado - F. A. Branson; R. B. Miller; I. S. McQueen (Ecology, 1976)
P Phenological observations showed that most species occupying moist habitats continued active growth for longer periods and efficiency of water use was lower for species occupying dry habitats than for those in moist habitats.

Food supply and nest timing of broad-tailed hummingbirds in the Rocky Mountains - Nickolas M. Waser (Condor, 1976)
Journal Article Food Supply and Nest Timing of Broad-Tailed Hummingbirds in the Rocky Mountains Get access Nickolas M. Waser Nickolas M. Waser Department of Ecology and Evolutionary Biology, University of Arizona, Tuscan, Arizona 85721 and Rocky Mountain Biological Laboratory, Crested Butte, Colorado 81224. Accepted for publication 28 August 1974. Search for other works by this author on: Oxford Academic Google Scholar The Condor, Volume 78, Issue 1, 1 January 1976, Pages 133–135, https://doi.org/10.2307/1366943 Published: 01 January 1976 Article history Accepted: 27 August 1974 Published: 01 January 1976

Biotite-induced grussification of the Boulder Creek Granodiorite, Boulder County, Colorado - D. A. N. A. ISHERWOOD; ALAYNE STREET (Geological Society of America Bulletin, 1976)
Research Article| March 01, 1976 Biotite-induced grussification of the Boulder Creek Granodiorite, Boulder County, Colorado DANA ISHERWOOD; DANA ISHERWOOD 1Department of Geological Sciences, University of Colorado, Boulder, Colorado 80302 Search for other works by this author on: GSW Google Scholar ALAYNE STREET ALAYNE STREET 2Geography Department, Cambridge University, Cambridge, England Search for other works by this author on: GSW Google Scholar Author and Article Information DANA ISHERWOOD 1Department of Geological Sciences, University of Colorado, Boulder, Colorado 80302 ALAYNE STREET 2Geography Department, Cambridge University, Cambridge, England Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1976) 87 (3): 366–370. https://doi.org/10.1130/0016-7606(1976)87<366:BGOTBC>2.0.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 DANA ISHERWOOD, ALAYNE STREET; Biotite-induced grussification of the Boulder Creek Granodiorite, Boulder County, Colorado. GSA Bulletin 1976;; 87 (3): 366–370. doi: https://doi.org/10.1130/0016-7606(1976)87<366:BGOTBC>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Grus formation in the Precambrian Boulder Creek Granodiorite of Colorado is the result of biotite expansion along basal cleavages. A petrographic study of the grus, impregnated in plastic resin to retain its original fabric, reveals expanded biotite fragments separated by void space with numerous microfractures through quartz and feldspar grains. Mineral alteration during grussification includes hornblende solution and argillation of feldspar. X-ray analysis of the weathered biotite indicates the formation of hydrobiotite and biotite-hydrobiotite interlayer combinations. Chemical changes in the composition of the biotite are not excessive and consist mainly of oxidation of Fe+2 to Fe+3 with replacement of K+1 by water molecules. These changes have decreased the biotite density from 3.08 g/cm3 to 2.50 g/cm3. Modal analyses of fresh and weathered samples suggest that grussification is a function of biotite content: the greater the biotite percentage, the greater the susceptibility for granular disintegration to occur. The formation of microfractures and the expansion of the biotite have reduced the bulk density from 2.67 g/cm3 for the original rock to 1.98 g/cm3 for the grus. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

U-Pb age of zircon from Vernal Mesa-type quartz monzonite, Unaweep Canyon, west-central Colorado - M. E. Bickford; T. F. CUDZILO (Geological Society of America Bulletin, 1975)
Research Article| October 01, 1975 U-Pb age of zircon from Vernal Mesa-type quartz monzonite, Unaweep Canyon, west-central Colorado M. E. BICKFORD; M. E. BICKFORD 1Department of Geology, University of Kansas, Lawrence, Kansas 66045 Search for other works by this author on: GSW Google Scholar T. F. CUDZILO T. F. CUDZILO 1Department of Geology, University of Kansas, Lawrence, Kansas 660452Present address: Chevron Oil Company, Minerals Staff, Box 599, Denver, Colorado 80201. Search for other works by this author on: GSW Google Scholar Author and Article Information M. E. BICKFORD 1Department of Geology, University of Kansas, Lawrence, Kansas 66045 T. F. CUDZILO 1Department of Geology, University of Kansas, Lawrence, Kansas 660452Present address: Chevron Oil Company, Minerals Staff, Box 599, Denver, Colorado 80201. Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1975) 86 (10): 1432–1434. https://doi.org/10.1130/0016-7606(1975)86<1432:UAOZFV>2.0.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 M. E. BICKFORD, T. F. CUDZILO; U-Pb age of zircon from Vernal Mesa-type quartz monzonite, Unaweep Canyon, west-central Colorado. GSA Bulletin 1975;; 86 (10): 1432–1434. doi: https://doi.org/10.1130/0016-7606(1975)86<1432:UAOZFV>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract The Vernal Mesa-type quartz monzonite is an igneous body of batholithic proportions of Precambrian age in western Colorado and eastern Utah. A Rb-Sr age of 1,480 ± 40 m.y. has been previously reported; other Rb-Sr data reported suggest that the rock might be as much as 200 m.y. older than this. The U-Pb age of the suite of zircons is 1,443 ± 22 m.y., confirming that the Vernal Mesa was formed during the igneous activity which was widespread in the southwestern and central United States 1,450 to 1,500 m.y. ago. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Neogene Tectonism in South-Central Colorado - Richard B. Taylor (Memoir - Geological Society of America, 1975)
Miocene-Pliocene history is recorded in south-central Colorado by sediments deposited in subsiding basins bounded by fault-block mountains and by faulted sedimentary and volcanic deposits lying on a channeled late Eocene erosion surface of regional extent. The San Luis Valley and upper Arkansas Valley are en echelon segments of the Rio Grande trough that are constricted and faulted south of Salida at the northern end of the Sangre de Cristo Range. Great movements on the bounding faults during Neogene time are indicated by clastic and volcanic trough fill, which may be 10,000 m thick near Alamosa and 1,500 m thick near...

Enzyme polymorphism and adaptation - G. C. Johnson (Stadler Genetics Symposium, 1975)

Faunal report - D. Rowe (1975)

Cryptogam Distributions on Pseudotsuga menziesii and Abies lasiocarpa in the Front Range, Boulder County, Colorado - Larry P. Gough (The Bryologist, 1975)
Forty-six lichens, two mosses and one fungus were studied on the trunks of Pseudotsuga menziesii (Mirb.) Franco and Abies lasiocarpa (Hook.) Nutt. at five elevations in Boulder County, Colorado. Arthonia mediella Nyl., Cladonia bacillaris (Ach.) Nyl., Lecanora expallens Ach., L. hypoptoides Nyl., L. piniperda Kirb., Lecidea plebeja Nyl. and Rinodina pachysperma Magn. are reported for the first time from Colorado. The vertical, horizontal (aspectual) and elevational distributions of the cryptogams were ascertained both quantitatively and qualitatively. Eleven taxa were exclusive to P. menziesii, 17 taxa were exclusive to A. lasiocarpa and 19 taxa were common to both. The rate of bark scaling appeared to be the most important substrate feature governing the abundance of epiphytic growth on different conifer tree species. The study of distribution and ecology of corticolous cryptogamic epiphytes on specific tree species has been approached in the following ways: 1) species lists with notes on preferred substrate have always been a part of the general lichenological literature; 2) horizontal and vertical distributional studies of individual corticolous epiphytes, coupled with ecological notes, have appeared within the past forty years (Raup, 1930; Hale, 1952, 1965; Culberson, 1955; Coleman et al., 1956; Pearson, 1969; Kalgutkar & Bird, 1969; Jonescu, 1970; Hinds, 1970; Adams & Risser, 1971; Yarranton, 1972); 3) synecological studies have emerged within the past 20 years relating community structure to environment (Szczawinski, 1953; Barkman, 1958; Hoffman & Kazmierski, 1969); and 4) pioneering ecophysiological studies have only recently appeared (Harris, 1971). The latter are hampered by inability to grow lichens easily in the laboratory (Ahmadjian, 1967). There are large geographical areas that have been excluded in studies similar to those listed above, including many areas in the Rocky Mountains. Weber and Shushan (1955), Anderson (1962, 1964, 1974), Weber (1965, 1968), Shushan (1966), Shushan and Anderson (1969) and Egan (1971) have all published taxonomic works on lichens in the southern Rocky Mountains of the United States. Kalgutkar and Bird (1969) have extensively studied the autecology of corticolous lichens in the Canadian 1 This article is based on a dissertation submitted in partial fulfillment of the requirements of the Ph.D. in biology, University of Colorado, 1973. I thank Dr. Sam Shushan for guidance throughout the study, Drs. John Thomson, J. W. Sheard, Antonin Vizda and Wilhelm Solheim for consultation and Mr. Dwight Hamilton, Chief Park Naturalist, for courtesies extended in Rocky Mountain National Park. Financial assistance through the Department of Environmental, Population and Organismic Biology at the Unversity of Colorado is gratefully noted. 2 U.S. Geological Survey, Denver, Colorado 80225. This content downloaded from 157.55.39.102 on Mon, 03 Oct 2016 04:19:16 UTC All use subject to http://about.jstor.org/terms 1975] GOUGH: CRYPTOGAM DISTRIBUTIONS ON CONIFERS 125 105 40 300 20 0 m0les OOES PAR9qRK I Lake Estes 0I5 ,F 0_IF0 r7, kil ometers r0 ,2745, 4001 Bonld

Middle Tertiary Volcanic Field in the Southern Rocky Mountains - Thomas A. Steven (Memoir - Geological Society of America, 1975)
A widespread volcanic field covered most of the Southern Rocky Mountains in middle Tertiary time, 40 to 25 m.y. ago (approximately Oligocene time). This field covered an erosion surface that beveled structures formed during the Laramide orogeny in Late Cretaceous and early Tertiary time. The source vents from which the volcanic rocks were derived were largely restricted to the deformed area. Recognized volcanic centers lie mostly within a broad triangular area bounded on the east by the Rocky Mountain front, on the northwest by the northeast-trending Colorado mineral belt lineament, and on the southwest by the southern margin of the recurrently active Uncompahgre-San Luis uplift. Local volcanic centers existed also in the Never Summer Mountains and Rabbit Ears Range north of the mineral belt lineament. The resulting volcanic field thus consisted of a major southern segment covering all of south-central Colorado and adjacent New Mexico and a northern segment extending into the mountain areas of north-central Colorado. The two segments were linked along the trend of the Colorado mineral belt.

Affinities of Lupinus prunophilus Jones and L. ammophilus Greene (Papilionaceae) - B. J. Cox (Southwestern Naturalist, 1975)
The confused taxonomic history of prunophilus (Papilionaceae) is discussed and its affinities with the morphologically similar L. ammophilus and other putative relatives within the L. ornatus complex and morphologically similar complexes are elucidated. Chemosystematic evidence of alkaloid comparisons support the orthodox morphological, ecological, and geographical distribution data indicating the distinction of the two species; alkaloids lend a diagnostic marker to L. prunophilus. These data are correlated with previous evolution studies in concluding that L.. prunophilus was derived from the California epicenter in a manner similar to that proposed for other members of the L. ornatus complex and most North American lupines, whereas L. ammophilus was derived from the southern Rocky Mountains, being related more closely to the United States east coast L. perennis complex and the Mexican L. madrensis complex. The taxonomy of the genus (Papilionaceae) is generally thought to be in a more chaotic state than most other groups of plants. This is partially attributed to the extreme plasticity of the species (Cox 1970) and partially because of insufficient study. While several taxonomists have attempted to describe and attach epithets to every variant lupine population (e.g., Smith 1927), others have lumped large numbers of divergent taxa (Phillips 1955; Hitchcock et al. 1961). Many lupine descriptions are so vague and the taxonomic treatments disagree so tremendously that one is generally in doubt as to the identity of the species in hand. This largely accounts for the reason for so many lupine specimens, some dating back to the mid 1800's, labeled only Lupinus sp. or are grossly misidentified. Insight is gained into the parameters of variation and affinities of the species by monographic studies where geographic distribution is plotted in conjunction with and as a test for morphological, ecological, and chemical data. I developed a special interest in prunophilus Jones and in its relationship to L. ammophilus Greene while monographing the 1 Study conducted at Division of Biological Sciences, University of Missouri, Columbia, Missouri 65201.

Why don't more hummingbird-pollinated flowers have dark-colored pollen? - David W. Inouye (American Naturalist, 1975)
This note derives from work done during an NSF predoctoral fellowship at the University of California, Santa Barbara (UCSB).

Life histories of three species of Corixidae (Hemiptera: Heteroptera) from western Colorado - V. E. Dodson (American Midland Naturalist, 1975)
Life histories of three species of Corixidae found only at altitudes over 2800 m were compared. The number of generations per year varied with altitude. Callicorixa audeni Hung. and Cenocorixa bifida Hung. had two or more generations a summer in montane ponds (below 3100 m) and only one generation a summer above 3100 m. These two species had synchronous life histories in ponds where they occurred together. Arctocorisa lawsoni Hung. was found only above 3100 m and produced a single generation per summer. Where A. lawsoni and C. audeni occurred together, A. lawsoni's development was one instar ahead of C. audeni. All three species overwintered as adults. Some evidence for wing muscle polymorphism in Cenocorixa bifida was discovered in one montane pond (2890 m).

Thermoregulation and water requirements in semiarid and montane populations of the least chipmunk, Eutamias minimus. III. Acclimatization at a high ambient temperature - N. J. Willems; Kenneth B. Armitage (Comparative Biochemistry and Physiology, 1975)
Adaptation of E. minimus to the semiarid habitat has involved changes in response to acute and chronic heat and water stress which increase the time the chipmunks can survive exposures to high ambient temperature, regardless of water availability.

A mutualistic ant-plant relationship from a high altitude temperate region - David W. Inouye; O. R. Taylor (American Zoologist, 1975)

Late Cenozoic Basic Volcanism in Northwestern Colorado and Its Implications Concerning Tectonism and the Origin of the Colorado River System - E. E. Larson; Minoru Ozima; William C. Bradley (Memoir - Geological Society of America, 1975)
Upper Cenozoic terrestrial basin-fill sedimentary and basic volcanic rocks are common in the 20,700 km2 Basalt area, which includes parts of the Gore, Sawatch, and southern Park Ranges, Elk Mountains, Grand Mesa, and White River Plateau. Principally on the basis of whole-rock K-Ar ages from basalt flows, the rocks can be placed in four groups. Group 1 rocks attain a thickness of 210 m and range in age from 24 to 20 m.y. (early Miocene). They consist primarily of flows of alkali-olivine basalt or of basalt flows interlayered with cross-bedded sandstone of the Browns Park Formation. Group 2 rocks, 14 to 9 m.y. old (late Miocene and perhaps early Pliocene), attain a maximum thickness of 180 m and are composed largely of basalt, basaltic andesite, and fine-grained tuffaceous fluvial, lacustrine, and eolian sedimentary rocks containing a rich vertebrate fauna indicative of a semiarid climate and a steppe vegetation. Toward the end stages of the accumulation of group 2 rocks, about 10 m.y. ago, the region was subjected to major tectonism, including uplift, reactivation of some Laramide (Late Cretaceous-early Tertiary) structural features, and creation of new warps, folds, and faults. The initiation of the Colorado River system apparently occurred at that time in response to increased precipitation stemming from an increase in elevation and relief. Downcutting began at this time and has continued intermittently to the present. By about 8 m.y. ago (late Miocene or early Pliocene, depending on boundary interpretation), the Roaring Fork River had downcut 600 m and had formed a broad flood plain, upon which thin alkali-olivine basalt flow units (group 3 rocks) were erupted. Downcutting appears to have been slow between about 8 and 1.5 m.y. ago; since then, an additional 300 m of valley deepening has occurred. Sporadic volcanism since 1.5 m.y. has accounted for several small cinder cones and flows of nepheline-normative alkali basalt (group 4 rocks); the last eruption occurred about 4,000 yr ago.

Faunal report - S. Reeder (1975)

Faunal report - D. Rowe; M. Haldi; S. Reeder; Joel Q.G. Spencer (1975)

Dispersion of offspring in Spermophilus lateralis - N. A. Peterson (1975)

The distributional ecology and diversity of benthic insects in Cement Creek, Colorado - J. D. Allan (Ecology, 1975)
Distributional patterns and species diversity of benthic insects in an alpine stream in Gunnison County, Colorado, USA were investigated on several levels of spatial scale, from faunal replacement over 1,000 vertical m to microdistribution within the stony substratum. Ecotones including zonation in terrestrial vegetation and in trout distribution did not appear to affect faunal replacement. Competition among congeners accounted for 7—30% of the cases, while in the majority of species, faunal replacement appeared to be associated with gradual changes in the physical gradient. Trout zonation may affect total numbers of insects, however, as the trout—free headwaters had two to six times higher insect densities. Microdistribution was investigated by measures of species and substratum patterning in a series of microhabitats (0.093 m2) at a series of sites (separated by 75—150 vertical m), and by field colonization experiments with various substratum choices. I hypothesize that increased substratum complexity leads to greater species richness based on several lines of evidence: (1) different species showed different substratum preferences, (2) colonization of mixed substrata generally resulted in greater mean species richness than did colonization of a single substratum type, and (3) both species diversity and substratum complexity were greatest at the within—microhabitat level. However, substratum composition showed little variation along the elevational gradient and did not appear to be a cause of faunal replacement. The several scales of investigation were complementary, as congeners exhibiting sharp mutual exclusion in vertical distribution had similar microhabitat preferences, while other congeners showed less exclusion and differed in microhabitat preferences. Most of species diversity as measured by H' was found within habitats rather than between habitats while species richness depended equally upon within—habitat variation (owing to rare species) and between—habitat variation (owing to faunal replacement).

Eocene fossil mammalia from the Sand Wash Basin, northwestern Moffat County, Colorado - Robert M. West; Mary R. Dawson (Annals of the Carnegie Museum, 1975)

Faunal report - Joel Q.G. Spencer (1975)

Possible impairment of nest-building of hummingbirds by acetate leg tags - Nickolas M. Waser; W. A. Calder (Condor, 1975)
Journal Article Possible Impairment of Nest-Building of Hummingbirds by Acetate Leg Tags Get access Nickolas M. Waser, Nickolas M. Waser Department of Biological Sciences The University of Arizona Tucson, Arizona 85721 Rocky Mountain Biological Laboratory Crested Butte, Colorado 81224 Search for other works by this author on: Oxford Academic Google Scholar William A. Calder William A. Calder Department of Biological Sciences The University of Arizona Tucson, Arizona 85721 Rocky Mountain Biological Laboratory Crested Butte, Colorado 81224 Search for other works by this author on: Oxford Academic Google Scholar The Condor, Volume 77, Issue 3, 1 July 1975, Page 361, https://doi.org/10.2307/1366251 Published: 01 July 1975 Article history Accepted: 13 February 1974 Published: 01 July 1975

Linkage disequilibrium over space and time in natural populations of Drosophila montana - W. K. Baker (Proceedings of the National Academy of Science, 1975)
The previously described allelic frequencies and linkage disequilibrium among the active and null alleles of four tightly linked loci coding for the alpha-esterases were found to be maintained by one population for 5 years, and were found to be present in two other populations which were shown to be genetically distinct from the first. It appears that enzyme variants coded by these highly polymorphic loci are being maintained in the populations by selective forces.

Daylength and the hummingbird's use of time - W. A. Calder (Auk, 1975)
PHYSIOLOGIcAL homeostasis is maintained with energy that a bird must extract from its environment. Effective investment of the bird's time in exchange for the necessary energy must be the objective of maintenance strategy. If the rate of intake is less than the metabolic rate over a period of time, homeostasis is impossible. The temporal aspects involved in attainment of energy balance by a diurnal bird include duration of adequate light for effective foraging, cyclic availability of food, flight time to a food source or successful prey capture, duration of the nocturnal fast, and the daily environmental temperature cycle that will influence the overall energy cost. In summer the length of daylight for foraging increases with latitude, and the duration of the nocturnal fast decreases. In winter, the ratio of feeding time to fasting time is reduced with increasing latitude. The endurance of fasting would be directly proportional to the amount of energy in reserve and inversely related to the rate of degradation of the reserves:

Mountain chickadee - D. Rowe (1975)

Spermophilus lateralis feeding behavior - T. Young (1975)

Summer studies of gray-headed junco at RMBL - M. Williamson (1975)

Mammal fauna species diversity, distribution and microhabitat selection - D. R. Ludwig (1975)

A study of the nesting behavior of the Lincoln sparrow (Melospiza lincolnii lincolnii) - Joel Q.G. Spencer (1975)

Social organization among marmot young - D. G. Rhoades (1975)

Raphidiids: territoriality, oviposition, and feeding behaviors - N. E. Pierce (1975)

Natural history of a talus/aspen grove ecotone - O. D. McClain (1975)

A project on a female broad-tailed hummingbird exhibiting territorial defence and coexistence with a different species, robins through habituation - S. S. B. S. Hussain (1975)

Responses of yellow-bellied sapsuckers to playback of recorded drumming sequences - D. A. Crusoe (1975)

Slowed motion analysis of sound production in the grasshopper, Arphia sulphurea (Acrididae: Dedipodinae) - R. L. Willey (Psyche, 1975)

Checkerspot butterflies: a historical perspective - P. R. Ehrlich; R. R. White; M. C. Singer; W. W. McKechnie; L. E. Gilbert (Science, 1975)

Faunal replacement: altitudinal zonation in an alpine stream - J. D. Allan (Verhandlungen der Internationale Vereinigung fr Theoretische und Angewandte Limnologie, 1975)

The social behavior and nest aggregation of the red-winged blackbirds, Agelaius phoeniceus in a kettle pond located near Gothic, Colorado - R. L. Goodyear (1975)

Some conclusions to my observations of the red-winged blackbird at the kettle ponds near Gothic - W. S. Eddy (1975)

Study of the mammal fauna of a meadow-aspen ecotone on a hill overlooking the kettle ponds - M. Burdick (1975)

The American orb-weaver genera Larinia, Cercidia, and Mangora north of Mexico (Araneae, Araneidae) - H. W. Levi (Bull Mus Comp Zool, 1975)

Behavioral thermoregulation in high altitude tiger salamanders, Ambystoma tigrinum - A. G. Heath (Herpetologica, 1975)

Coevolution of pierid butterflies and their cruciferous foodplants. I. The relative quality of available resources - F. S. Chew (Oecologia, 1975)

Spacing postures and territorial behavior in the golden mantled ground squirrel (Callospermophilus lateralis) - C. B. Hathaway (1975)

Song dialects and genetic differences in white-crowned sparrows (Zonotrichia leucophrys) - M. C. Baker (Evolution, 1975)

Mammalogy faunal report for Virginia Basin - R. Robertson (1975)

Social behavior and population dynamics of marmots - Kenneth B. Armitage (Oikos, 1975)
Population dynamics and social behavior of 5 populations were studied for 10 yr. Agonistic behavior characterized social interactions among adult females and yearlings who were subordinate. Rates of amicable and of agonistic behavior varied widely within a harem from year to year and among harems in any given year. Mean interaction rate and mean number of residents were unrelated. Rates of amicable behavior were not related to population density in any colony; the rate of agonistic behavior was associated with population density only in one colony. Rates of amicable and of agonistic behavior between adult males and yearling females, between yearling females and adult females, and among adult females were independent of measures of population density whether data from all colonies were lumped or whether colonies were treated separately. There was no significant relationship between the mean size of home ranges and the mean number of resident adult females. The mean number of resident females was significantly and positively correlated with the percent overlap of home ranges. Patterns of social behavior and home range were slightly related. Female yearlings were more likely to become residents if their home ranges overlapped those of adult females by more than 50 %. Recruitment of females was associated with a high percentage overlap of home ranges and with social tolerance; decline in the number of residents, a small number of residents, or a lack of recruitment of new residents was associated with social intolerance. A model relating social behavior to population changes emphasizes behavioral density, a function of the number of animals of each behavioral type present in the population, as the factor controlling recruitment.

Thermoregulation and water requirements in semiarid and montane populations of the least chipmunk, Eutamias minimus. I. Metabolic rate and body temperature - N. J. Willems; Kenneth B. Armitage (Comparative Biochemistry and Physiology, 1975)

Socio-ecology of Marmota: reproductive strategies of female yellow-bellied marmots (M. flaviventris) - D. C. Andersen (1975)

Pigmy shrew, Microsorex hoyi, in Gunnison County, Colorado - S. L. DeMott; G. P. Lindsey (Southwestern Naturalist, 1975)

Mammal species in meadows near Gothic - T. K. Werner (1975)

A geographical analysis of quantitative morphological variation in the grasshopper Arphia conspersa - W. E. Schennum (1975)

An analysis of tree swallow behavior - C. R. Urbina (1975)

Analysis of morphological variation as a function of altitude in populations of Thlaspi alpestre L - D. G. Rhoades (1975)

Aggressive behavior in ants - K. McFadden (1975)

Community-level interaction in avian vocalizations - S. Martindale (1975)

Correlation between the feeding activity and the pattern of feeding of Turdus migratorus at two localities - S. S. B. S. Hussain (1975)

A quantitative analysis of maintenance behavior of the yellow-bellied sapsucker (Sphyrapicus varius nuchalis) - D. A. Crusoe (1975)

Perspectives in Biophysical Ecology - W. A. Calder (1975)

Distribution of caddisfly larvae at varying densities - M. Williamson (1975)

Mating and coloniality in the cliff swallow, Petrochelidon pyrrhonota - R. Silver (1975)

On the anti-predatory behavior of Ochotona princeps, a discussion of observations - O. D. McClain (1975)

Evolutionary considerations of the sleek, souped-up swallow-to-follow, the ordinary flat-lands bugeater - S. Martindale (1975)

Mammalian Fauna of two sub-alpine habitats - C. B. Hathaway (1975)

A study of social organization in Eutamias minimus, "the least chipmunk - B. Gentry (1975)

Scent marking behavior in Ochotona princeps - L. Arias (1975)

Thermoregulation and water requirements in semiarid and montane populations of the least chipmunk, Eutamias minimus. II. Water balance - N. J. Willems; Kenneth B. Armitage (Comparative Biochemistry and Physiology, 1975)

Colacium libellae sp. nov. (Euglenophycea): a photosynthetic inhabitant of the larval damselfly rectum - J. R. Rosowski; R. L. Willey (Journal of Phycology, 1975)

The distribution and habitat separation of three corixids (Hemiptera: Heteroptera) in western Colorado - V. E. Dodson (Freshwater Biology, 1975)
SummaryThree species of Corixidae (Hemiptera : Heteroptera) were studied in thirty montane, sub‐alpine, and alpine ponds in Western Colorado. Callicorixa audeni Hung, had the widest altitudinal range (2800‐3400 m). Cenocorixa bifida Hung, was most common in montane ponds. Arctocorisa lawsoni Hung, was found only above 3100 m. C. audeni was significantly associated with C. bifida and A. lawsoni. Habitat selection was studied in two montane (2900 m) and one alpine (3480 m) pond. C. audeni utilized both mud and emergent sedges as perching and feeding sites, occurring more frequently in the sedges in the montane ponds. C. bifida was confined to the mud. In the alpine pond, A. lawsoni was most abundant on the mud; C. audeni occurred equally on the mud and in the sedges. All three species preferred shallow water (less than 0·5 m). A. lawsoni occupied deeper water more often than C. audeni. In substrate selection experiments C. audeni occupied emergent sedges more than C. bifida, confirming field observations. C. bifida occurred in sedges in the aquaria, but not in the montane ponds, suggesting that an interspecific interaction may be excluding C. bifida from the sedges in nature.

Mutualism between ants and Helianthella - H. D. Hasbrouck (1974)

Trichopteran larvae case rebuilding behavior - L. R. Desmond (1974)

Reproductive biology of Listera borealis - P. Gross (1974)

Changes in diversity with extremes - Jeffrey S. Dean (1974)

Sedge succession in four ponds - A. Carpenter (1974)

Emergence patterns of the subalpine dragonfly Somatochlora semicircularis (Odonata: Corduliidae) - R. L. Willey (Psyche, 1974)

Is DNA the only chromosomal component contributing to target size for mutation induction? - A. D. Conger (Mutation Research, 1974)

Size differences in Baetis - R. Bruesewitz (1974)

Nectar resource use by Colias butterflies: chemical and visual aspects - W. B. Watt; P. C. Hoch; G. Mills (Oecologia, 1974)

Differences in standing times of trout in a pond and trout in a stream - R. Walkosz (1974)

Pollination biology and population resources in the genus Aquilegia (Ranunculaceae) - R. B. Miller (1974)

Sandpiper behavior - R. S. Inouye (1974)

The prey preferences of two different aquatic beetle larvae - R. Walkosz (1974)

Mist-netting bats - R. DeVore (1974)