The purpose of this study was to describe and determine the prevalence of decision-making characteristics of recreational backcountry groups when making a decision of where to travel and ride in avalanche terrain from the perspective of individuals. Decision-making characteristics encompassed commun

292 Warren, Birds of the Elk Mountain Region, Colo.[sae now be held of specific value, as no intermediate specimens are: forthcoming."It remained for M. Johan Beetz to point out the fact that there is an intermediate form between dresseri and borealis.Instead of this form.beinga new species, as M. B

Disruptions to functionally important symbionts with global change will negatively impact plant fitness, with broader consequences for species' abundances, distribution, and community composition. Fungal endophytes that live inside plant leaves and roots could potentially mitigate plant heat stress

Mazzettiite, ideally Ag3HgPbSbTe5, is a new mineral species from Findley Gulch, Saguache County, Colorado. It occurs as anhedral to subhedral grains up to 200 m across, closely associated with altaite together with galena in a gangue of quartz. Mazzettiite is opaque with a metallic luster and a blac

I review a case study of marmots that contributed to the empirical basis of the nonlinearity and fear hypothesis, which explains why certain nonlinear acoustic phenomena (NLP) are produced in extremely high-risk situations and communicate high urgency. In response to detecting predatory threats, yel

New interactions with non-native species can alter selection pressures on native species. Here, we examined the effect of the spatial distribution of a non-native species, a factor that determines ecological and evolutionary outcomes but that is poorly understood, particularly on a fine scale. Speci

Abstract: A pilot biochemical reactor (BCR) was designed and constructed to treat mine-influenced water emanating from an adit at a remote site in southern Colorado which receives an average of 400 inches (10.2 m) of snowfall each season. The objective of the study is to operate and monitor a BCR on

Global environmental changes induced by human activities are forcing organisms to respond at an unprecedented pace. At present we have only a limited understanding of why some species possess the capacity to respond to these changes while others do not. We introduce the concept of multidimensional p

Patterns of egg distribution and survivorship were examined for six generations of a univoltine population of the pierid butterfly Colias alexandra, finding that among clumped individuals, survivorship is two times greater for the first or previously-laid individual than the second or subsequently-

The Gothic and Maroon formations are the most significant Upper Paleozoic lithogenetic units between Copper Creek and Glenwood Springs, Colorado. Thin limestones were traced southward from Glenwood Springs to Redstone and furnish local horizons of time-rock correlation. They do not, however, mark th

The nonlinearity and fear hypothesis predicts that the structure of alarm vocalizations will be influenced by the signaller's internal state. Specifically, stressed or otherwise more aroused individuals will produce alarm calls that are relatively more nonlinear (i.e. they sound noisier). The positi

Results of three years of study on the host plant affiliations of two lycaenid butterfly species (Lycaenidae) suggest that differences between the two butterflies in host plant range, plant tissue oviposited on by adults and consumed by larvae, larval growth rates, and adult flight season may be con

Allocation of stored and incoming nutrients to reproduction determines an organism’s age-specific fecundity curve. In holometabolous insects, differences among species in the shape of the curve are correlated with differences in the potential importance of adult food to reproduction. I examined allo

Experimental ecologists have frequently used cages to facilitate their understanding of ecological systems. This has been particularly true of ecologists studying aphids and other small insects, and a variety of cage designs have been described, ranging from small screened tents to sleeve cages to c

In the Colorado River, hydrologic and legal conditions create difficulty in sharing water effectively and equitably during a deep 22-year drought. Demand outstrips supply, water entitlements are over-appropriated, and institutional arrangements are nearly gridlocked. The crisis poses challenges not

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.

BENT, A. C. 1942. Life histories of North American flycatchers, larks, swallows and their allies. U.S. Natl. Mus. Bull. 179. BUDD, L. F., R. B. AREND, J. W. HURST, AND V. H. ANDERSON. 1979. Fort Bliss environmental analysis and impact assessment. Photographic Interpretation Corporation, Hanover, New