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Clonal expansion and seedling recruitment of Oregon grape (Berberis nervosa) in Douglas-fir (Pseudotsuga menziesii) forests: Comparisons with salal (Gaultheria shallon) Clonal expansion and seedling recruitment of Oregon grape (Berberis nervosa) in Douglas-fir (Pseudotsuga menziesii) forests: Comparisons with salal (Gaultheria shallon)

Seedling regeneration and morphology of Oregon grape (Berberis nervosa Pursh) and salal (Gaultheria shallon Pursh) were studied in thinned and unthinned Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stands in the central Coast Range, Oregon. Above- and below-ground growth of both species were significantly and negatively correlated with stand density. Oregon grape appears to have...
Authors
David W. Huffman, John C. Tappeiner

Primary song by a juvenile willow flycatcher Primary song by a juvenile willow flycatcher

The timing of song development in suboscines, in which song appears not to be learned from other adults is poorly known. The Willow Flycatcher (Empidonax traillii) is a suboscine with a primary song typically referred to as fitz-bew. I report here an instance of very early singing by a 6-8-wk-old Willow Flycatcher, which sang in an aggressive context in response to a recording of adult...
Authors
M. K. Sogge

The role of sediment ingestion in exposing wood ducks to lead The role of sediment ingestion in exposing wood ducks to lead

Waterfowl on lateral lakes of the Coeur d'Alene River and on Lake Coeur d'Alene have been poisoned for many years by lead (Pb) from mining and smelting. In 1992 we undertook a study in the area to determine the importance of sediment ingestion in exposing wood ducks (Aix sponsa) to Pb. Digesta were removed from the intestines of wood ducks collected from contaminated and reference areas...
Authors
W. N. Beyer, L. J. Blus, Charles J. Henny, D. Audet

Clarification of effects of DDE on shell thickness, size, mass, and shape of avian eggs 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...
Authors
Lawrence J. Blus, Stanley N. Wiemeyer, Christine M. Bunck

Population dynamics of the deer mouse (Peromyscus maniculatus) and Sin Nombre Virus, California Channel Islands 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
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 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...
Authors
E.C. Theriot, S.C. Fritz, Robert E. Gresswell

Interactive effects of prey and weather on golden eagle reproduction Interactive effects of prey and weather on golden eagle reproduction

1. The reproduction of the golden eagle Aquila chrysaetos was studied in southwestern Idaho for 23 years, and the relationship between eagle reproduction and jackrabbit Lepus californicus abundance, weather factors, and their interactions, was modelled using general linear models. Backward elimination procedures were used to arrive at parsimonious models. 2. The number of golden eagle...
Authors
Karen Steenhof, Michael N. Kochert, T. L. McDonald

Using mark-recapture methods to estimate fish abundance in small mountain lakes 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...
Authors
Robert E. Gresswell, W.J. Liss, G.A. Lomnicky, E. Deimling, Robert L. Hoffman, T. Tyler
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