Publications
Filter Total Items: 1999
DDE still high in white-faced ibis eggs from Carson Lake, Nevada
White-faced Ibis (Plegadis chihi) eggs collected in 1996 at Carson Lake, Nevada, showed no decrease in p,p′-DDE (DDE) concentrations from levels in 1985 and 1986 which is contrary to DDE patterns shown for most avian species. An estimated 40-45% of the population was adversely affected by DDE in 1985, 1986, and 1996 with a probable net loss of about 20% of the expected productivity. One segment of
Authors
Charles J. Henny
Photosynthesis of green algal soil crust lichens from arid lands in southern Utah, USA: Role of water content on light and temperature responses of CO2 exchange
Biotic soil crusts are a worldwide phenomenon in arid and semi-arid landscapes. Metabolic activity of the poikilohydric organisms found in these crusts is dominated by quick and drastic changes in moisture availability and long periods of drought. Under controlled conditions, we studied the role of water content on photosynthetic and respiratory CO2 exchange of three green algal soil crust lichens
Authors
Otto L. Lange, Jayne Belnap, Angelika Meyer
Population dynamics of the deer mouse (Peromyscus maniculatus) and Sin Nombre Virus, California Channel Islands
Hantavirus pulmonary syndrome, first documented in 1993, is caused by Sin Nombre virus (SNV), which is carried by the Peromyscus species. In 1994, high SNV antibody prevalence was identified in deer mice from two California Channel Islands. We sampled two locations on three islands to estimate mouse population density and SNV prevalence. Population flux and SNV prevalence appear to vary independen
Authors
T. B. Graham, B.B. Chomel
Long-term limnological data from the larger lakes of Yellowstone National Park, Wyoming, USA
Long-term limnological data from the four largest lakes in Yellowstone National Park (Yellowstone, Lewis, Shoshone, Heart) are used to characterize their limnology and patterns of temporal and spatial variability. Heart Lake has distinctively high concentrations of dissolved materials, apparently reflecting high thermal inputs. Shoshone and Lewis lakes have the highest total SiO2 concentrations (a
Authors
E.C. Theriot, S.C. Fritz, Robert E. Gresswell
Using mark-recapture methods to estimate fish abundance in small mountain lakes
The majority of lacustrine fish populations in the western USA are located far from the nearest
road. Although mark-recapture techniques are widely accepted for estimating population
abundance, these techniques have been broadly ignored for fisheries surveys in remote mountain
lakes because of restricted access and associated logistical constraints. In this study, mark recapture experiments wer
Authors
Robert E. Gresswell, W.J. Liss, G.A. Lomnicky, E. Deimling, Robert L. Hoffman, T. Tyler
Use of ungulates by Yellowstone grizzly bears Ursus arctos
Previous results of fecal analysis from the Yellowstone area and the known abilities of grizzly bears Ursus arctos to acquire and digest tissue from vertebrates suggested that grizzlies in this ecosystem obtained substantial energy from ungulates. This issue was addressed using observations from radio-marked grizzly bears, 1977–1992. Ungulates potentially contributed the majority of energy require
Authors
D.J. Mattson
Sustainable grizzly bear mortality calculated from counts of females with cubs-of-the-year: An evaluation
Unduplicated counts of female grizzly bears Ursus arctos horribilis with cubs-of-the-year are currently used to estimate minimum population sizes used, in turn, to calculate allowable (assumed to equal sustainable) mortality for grizzly bear populations in the contiguous United States of America. This calculation assumes that unduplicated counts are an unbiased and accurate indicator of population
Authors
David J. Mattson
Influence of basin-scale physical variables on life history characteristics of cutthroat trout in Yellowstone Lake
Individual spawning populations of Yellowstone cutthroat trout Oncorhynchus clarki bouvieri differ in life history characteristics associated with broad spatial and temporal environmental patterns, but relationships between specific life history characteristics of Yellowstone cutthroat trout and physical aspects of the environment are poorly understood. We examined basin-scale physical characteris
Authors
Robert E. Gresswell, W.J. Liss, Gary L. Larson, P. J. Bartlein
Wilderness-dependent wildlife: The large and carnivorous
Wilderness is vital to the conservation of wildlife species that are prone to conflict with humans and vulnerable to human-caused mortality. These species tend to be large and are often carnivorous. Such animals are typically problematic for humans because they kill livestock and, occasionally, humans, and cause inordinate damage to crops. The vulnerability of large herbivores and carnivores to hu
Authors
David J. Mattson
Excavation of red squirrel middens by grizzly bears in the whitebark pine zone
Whitebark pine seeds Pinus albicaulis are an important food of grizzly Ursus arctos horribilis bears wherever whitebark pine is abundant in the contiguous United States of America; availability of seeds affects the distribution of bears, and the level of conflict between bears and humans. Almost all of the seeds consumed by bears are excavated from middens where red squirrels Tamiasciurus hudsonic
Authors
D.J. Mattson, Daniel P. Reinhart
Use of lodgepole pine cover types by Yellowstone grizzly bears
Lodgepole pine (Pinus contorta) forests are a large and dynamic part of grizzly bear (Ursus arctos) habitat in the Yellowstone ecosystem. Research in other areas suggests that grizzly bears select for young open forest stands, especially for grazing and feeding on berries. Management guidelines accordingly recommend timber harvest as a technique for improving habitat in areas potentially dominated
Authors
D.J. Mattson
Clarification of effects of DDE on shell thickness, size, mass, and shape of avian eggs
Moriarty et al. (1986) used field data to conclude that DDE decreased the size or altered the shape of avian eggs; therefore, they postulated that decreased eggshell thickness was a secondary effect because, as a general rule, thickness and egg size are positively correlated. To further test this relationship, the present authors analyzed data from eggs of captive American kestrels. Falco sparveri
Authors
Lawrence J. Blus, Stanley N. Wiemeyer, Christine M. Bunck