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Publications

USGS research activities relevant to Alaska have yielded more than 9400 historical publications. This page features some of the most recent newsworthy research findings.

Filter Total Items: 3097

Classification of vegetation communities in which geese rear broods on the Yukon-Kuskokwim Delta, Alaska Classification of vegetation communities in which geese rear broods on the Yukon-Kuskokwim Delta, Alaska

Plant communities are described from an area on the Yukon – Kuskokwim (Y-K) delta of Alaska that is used extensively for brood rearing by three species of geese. Earlier studies identified plant species important as food for young geese, but few studies describe or quantify plant communities. We classified species presence or absence information from over 700 quadrats using a two-way...
Authors
Christopher Babcock, Craig R. Ely

Phylogeny and evolution of the auks (subfamily Alcinae) based on mitochondrial DNA sequences Phylogeny and evolution of the auks (subfamily Alcinae) based on mitochondrial DNA sequences

The genetic divergence and phylogeny of the auks was assessed by mitochondrial DNA sequence comparisons in a study using 19 of the 22 auk species and two outgroup representatives. We compared more than 500 nucleotides from each of two mitochondrial genes encoding 12S rRNA and the NADH dehydrogenase subunit 6. Divergence times were estimated from transversional substitutions. The dovekie...
Authors
Truls Moum, Steinar Johansen, Kjell Einar Erikstad, John F. Piatt

Cytonuclear genetics of experimental fish hybrid zones inside Biosphere 2 Cytonuclear genetics of experimental fish hybrid zones inside Biosphere 2

Two species of mosquitofish (family Poeciliidae) known to hybridize in nature were introduced into freshwater habitats inside Biosphere 2, and their population genetics were monitored after 2 years. Within four to six generations, nuclear and cytoplasmic markers characteristic of Gambusia holbrooki had risen greatly in frequency, although some Gambusia affinis alleles and haplotypes were...
Authors
K.T. Scribner, John C. Avise

Blood sampling in juvenile buff-breasted sandpipers: Movement, weight change and survival Blood sampling in juvenile buff-breasted sandpipers: Movement, weight change and survival

The effect of blood sampling on juvenile Buff-breasted Sandpipers (Tryngites subruficollis) was evaluated by comparing movements, mass, and survival of 10 broods (37 chicks) that were bled and eight broods (31 chicks) that were not bled. Blood was sampled from the jugular vein of chicks when they weighed 9.1 ± 0.9 g (x̄ ± SD) on or within 1 d of hatch. Chicks showed few short-term...
Authors
Richard B. Lanctot

Hybrid zone studies: An interdisciplinary approach for the analysis of evolutionary processes Hybrid zone studies: An interdisciplinary approach for the analysis of evolutionary processes

There has been considerable debate in the ecological and evolutionary literature over the relative importance and rate by which microevolutionary processes operating at the population level result in separation and differentiation of lineages and populations, and ultimately in speciation. Our understanding of evolutionary processes have need greatly enhances through the study of...
Authors
Kim T. Scribner

Geology of Seward Peninsula and Saint Lawrence Island Geology of Seward Peninsula and Saint Lawrence Island

Seward Peninsula (Fig. 1) may be divided into two geologic terranes (Fig. 2) on the basis of stratigraphy, structure, and metamorphic history. The Seward terrane, an area 150 by 150 km in the central and eastern peninsula, is dominated by Precambrian(?) and early Paleozoic blueschist-, greenschist-, and amphibolite-facies schist and marble, and intruded by three suites of granitic rocks...
Authors
Alison B. Till, Julie A. Dumoulin

Geology of south-central Alaska Geology of south-central Alaska

South-central Alaska is defined as the region bounded by the Kuskokwim Mountains to the northwest, the basins north of the Alaska Range to the north, the Canadian border to the east, and the Chugach Mountains to the south (Fig. 1). This region, hereafter called the study area, includes the Alaska Range, the Wrangell, Nutzotin, and Talkeetna mountains, the Copper River and the Susitna...
Authors
Warren J. Nokleberg, George Plafker, Frederic H. Wilson

An intersection model for estimating sea otter mortality along the Kenai Peninsula An intersection model for estimating sea otter mortality along the Kenai Peninsula

We developed an intersection model to integrate parameters estimated from three distinct data sets that resulted from the Exxon Valdez oil spill: (1) the distribution, amount, and movements of spilled oil; (2) the distribution and abundance of sea otters along the Kenai Peninsula; and (3) the estimates of site-specific sea otter mortality relative to oil exposure from otters captured for
Authors
James L. Bodkin, Mark S. Udevitz

Using stable isotopes to determine seabird trophic relationships Using stable isotopes to determine seabird trophic relationships

1. The stable isotopes of nitrogen (δ15N) and carbon (δ13C) were analysed in 22 species of marine birds from coastal waters of the northeast Pacific Ocean. Analyses confirm that stable nitrogen isotopes can predict seabird trophic positions. 2. Based on δ15N analyses, seabird trophic-level inferences generally agree with those of conventional dietary studies, but suggest that lower...
Authors
Keith A. Hobson, John F. Piatt, Jay Pitocchelli
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