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: 3088
Reproductive implications of egg-size variation in Black Brant Reproductive implications of egg-size variation in Black Brant
We analyzed variation in egg size of Black Brant (Branta bernicla nigricans) in relation to clutch size, laying date, female age, year, and position in the laying sequence. A total of 3,478 eggs was measured over three years. Egg size increased with clutch size and female age, and decreased with laying date, year, and position in the laying sequence. We did not detect a negative...
Authors
Paul L. Flint, James S. Sedinger
Threshold foraging behavior of baleen whales Threshold foraging behavior of baleen whales
We conducted hydroacoustic surveys for capelin Mallotus villosus in Witless Bay, Newfoundland, Canada, on 61 days during the summers of 1983 to 1985. On 32 of those days in whlch capelin surveys were conducted, we observed a total of 129 baleen whales - Including 93 humpback Megaptera novaeangliae, 31 minke Balaenoptera acutorostrata and 5 fin whales B. phvsalus. Although a few whales...
Authors
John F. Piatt, David A. Methven
Change-in-ratio methods for estimating population size Change-in-ratio methods for estimating population size
Change-in-ratio (CIR) methods can provide an effective, low cost approach for estimating the size of wildlife populations. They rely on being able to observe changes in proportions of population subclasses that result from the removal of a known number of individuals from the population. These methods were first introduced in the 1940’s to estimate the size of populations with 2...
Authors
Mark S. Udevitz, Kenneth H. Pollock
Depositional history, nannofossil biostratigraphy, and correlation of Argo Abyssal Plain Sites 765 and 261 Depositional history, nannofossil biostratigraphy, and correlation of Argo Abyssal Plain Sites 765 and 261
Sediments from the Argo Abyssal Plain (AAP), northwest of Australia, are the oldest known from the Indian Ocean and were recovered from ODP Site 765 and DSDP Site 261. New biostratigraphic and sedimentologic data from these sites, as well as reinterpretations of earlier findings, indicate that basal sediments at both localities are of Late Jurassic age and delineate a history of starved
Authors
Julie A. Dumoulin, Paul R. Bown
Paleomagnetism and geochronology of 23 Ma gabbroic intrusions in the Keku Strait, Alaska, and implications for the Alexander Terrane Paleomagnetism and geochronology of 23 Ma gabbroic intrusions in the Keku Strait, Alaska, and implications for the Alexander Terrane
Samples of Tertiary gabbro from 24 sites in the Keku Strait, Alaska, help constrain the displacement history of the Alexander terrane. Step heating experiments on a plagioclase separate from these previously undated intrusions indicate a discordant 40Ar/39Ar age of 23.1 ± 1.7 Ma. The characteristic magnetization resides in magnetite, is easily isolated by thermal and alternating field
Authors
Peter J. Haeussler, Robert S. Coe, Paul R. Renne
Distribution, numbers, and habitat of Bristle-thighed Curlews (Numinous tahitiensis) on Rangiroa atoll Distribution, numbers, and habitat of Bristle-thighed Curlews (Numinous tahitiensis) on Rangiroa atoll
We assessed the numbers, distribution, and habitat of Bristle-tithed Curlews (Numinous tahitiensis) on Rangiroa Atoll, Tuamotu Archipelago, during a visit in April 1988. We estimated a total of 250-350 curlews on the atoll. These birds were seen only on the southern and western rims, where they were most common on (1) saltpans within clusters of small islets and (2) narrow channels...
Authors
Robert E. Gill, Roland L. Redmond
Molt frequency and size class distribution in the California spiny lobster (Panulirus interruptus), at San Nicolas Island, California Molt frequency and size class distribution in the California spiny lobster (Panulirus interruptus), at San Nicolas Island, California
No abstract available.
Authors
James L. Bodkin, L.B. Browne
Puffins as samplers of juvenile pollock and other forage fish in the Gulf of Alaska Puffins as samplers of juvenile pollock and other forage fish in the Gulf of Alaska
We sampled the nestling diets of tufted puffins (Fratercula cirrhata) and horned puffins (F. corniculata) in 3 years at colonies from the north-central Gulf of Alaska to the eastern Aleutian Islands, Alaska, USA. Overall, tufted puffins consumed (by weight) 41% sandlance (Ammodytes hexapterus), 22% capelin (Mallotus villosus), 19% walleye pollock (Theragra chalcogramma), 13% other fish...
Authors
Scott Hatch, Gerald A. Sanger
The distribution of seabirds and fish in relation to ocean currents in the southeastern Chukchi Sea The distribution of seabirds and fish in relation to ocean currents in the southeastern Chukchi Sea
In late August 1988, we studied the distribution of seabirds in the southeastern Chukchi Sea, particularly in waters near a major seabird colony at Cape Thompson. Foraging areas were characterized using hydrographic data obtained from hydroacoustic surveys for fish. Murres (Uria spp.) and Black-legged Kitttiwakes Rissa tridactyla breeding at Cape Thompson fed mostly on Arctic cod, which...
Authors
John F. Piatt, John L. Wells, Andrea MacCharles, Brian S. Fadely
The velocity field along the San Andreas Fault in central and southern California The velocity field along the San Andreas Fault in central and southern California
The velocity field within a 100‐km‐broad zone centered on the San Andreas fault between the Mexican border and San Francisco Bay has been inferred from repeated surveys of trilateration networks in the 1973–1989 interval. The velocity field has the appearance of a shear flow that remains parallel to the local strike of the fault even through such major deflections as the big bend of the...
Authors
Michael Lisowski, James C. Savage, W.H. Prescott
Mitochondrial-DNA phylogeny of deer (Cervidae) Mitochondrial-DNA phylogeny of deer (Cervidae)
Mitochondrial-DNA restriction-site maps were constructed for several cervid taxa in the subfamilies Cervinae and Odocoileinae. Parsimony analyses of restriction sites and pair-wise analyses of genetic distances resulted in dendrograms congruent with the subfamily designations. Relationships within the Odocoileinae determined from genetic distances generally were concordant with those for...
Authors
M. A. Cronin
Mitochondrial and nuclear genetic relationships of deer (Odocoileus spp.) in western North America Mitochondrial and nuclear genetic relationships of deer (Odocoileus spp.) in western North America
Odocoileus hemionus (mule deer and black-tailed deer) and Odocoileus virginanus (white-tailed deer) are sympatric in western North America and are characterized by distinct morphology, behavior, and allozyme allele frequencies. However, there is discordance among nuclear and mitochondrial genetic relationships, as mule deer (O. h. hemionus) and white-tailed deer have similar...
Authors
Matthew A. Cronin