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Gerald A. Sanger

Publications and source records attributed to Gerald A. Sanger.

6 recordsLinked to original sources
USGS1992

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, and 5% invertebrates, whereas horned puffins took 85% sandlance, 4% capelin, 2% pollock, 8% other fish, and <1 % invertebrates. All of the pollock consumed were young of the year, whereas 4 year-classes of capelin were present, from young of the year through spawning adults. Puffins took mostly first-year sandlance, but fish in their second year or older were also common at colonies near Kodiak, Alaska. The importance of juvenile pollock in the diet of tufted puffins varied geographically from little or no use in the north-central Gulf and Kodiak areas to moderate use (5 to 20%) in the Semidi and Shumagin Islands to heavy use (25 to 75%) in the Sandman Reefs and eastern Aleutians. An estimated 11 billion pollock were consumed by tufted puffins throughout the region in 1986. The proportion of pollock in puffin diets at the Semidi Islands was strongly correlated with independent estimates of cohort strength in 3 years. Puffins may thus provide a useful index of distribution and year class abundance of first-year pollock, a species that currently supports an important commercial fishery in the Gulf of Alaska.

Alaska↗
USGS1988

Fall migration of Ross' Gull ( Rhodostethia rosea ) in Alaskan Chukchi and Beaufort seas: Final report

Ross’ Gulls ( Rhodostethia rosea ) are a major component of the pelagic avifauna of the Alaskan Chukchi and Beaufort seas in fall. Until recently, however, their distribution, abundance, and phenology of occurrence in Alaskan waters was poorly known. Since 1970, a combination of shipboard, aerial, and land-based surveys has revealed the major features of this species’ post-breeding movements in Alaska.

Alaska↗
USGS1987

Winter diets of common murres and marbled murrelets in Kachemak Bay, Alaska

Knowledge of the winter diets of seabirds in high latitudes like Alaskan waters has been an elusive aspect of their biology. Scanty information on winter diets of Common Murres ( Uria aalge ) are available from the Pribilof Islands (Preble and McAtee 1923), California (Baltz and Morejohn 1977), Kodiak Island (Kraznow and Sanger 1986), Newfoundland (Tuck 1960), and the North Sea (Blake 1984), and for Marbled Murrelets ( Brachyramphus marmoratus ) from British Columbia (Munro and Clemens 1931, Carter 1984) and Kodiak (Krasnow and sanger 1986). This paper summarizes the diets of these two species, as observed during the winter season of 1977-1978 in Kachemak Bay, Alaska, as a part fo the Alaskan Outer Continental Shelf Environmental Assessment Program, OCSEAP (Sanger and Jones 1982; Krasnow and Sanger 1986; Fukuyama, Sanger, and Hironaka, unpubl.) and provides further interpretation of the data.

Alaska↗
USGS1986

Marine birds

In this chapter we review existing knowledge of marine birds in the Gulf of Alaska. Three estuarine systems in the Gulf provide critical habitat for migratory shorebirds and waterfowl: 1) the Stikine River Delta, 2) Cook Inlet, and 3) the Copper River Delta. Over 20 million waterbirds are estimated to use the latter system during spring migration. Western sandpipers, dunlin, and northern pintails numerically dominate this migration. Breeding populations of shorebirds and waterfowl in the Gulf are small compared with those elsewhere in Alaska. Of those Gulf regions suitable for nesting waterfowl and shorebirds, the Copper River Delta is the most important. Species diversity and the number of shorebirds wintering in the Gulf are low; however, water- fowl wintering in the Gulf number at least in the low millions. These birds concentrated in sheltered, near-shore regions where their epibenthic and infaunal prey are accessible. Over nine million seabirds (twenty-six species) nest in the Gulf of Alaska at more than 800 sites. Seabird productivity varies markedly. Food availability seems to have a large influence on reproductive success, especially for surface-feeding species such as the black-legged kittiwake. Seabird densities are highest over shelf and shelf-break habitats during spring migration and in summer. Sooty and short-tailed shearwaters dominate the pelagic avifauna both numerically and in terms of biomass. Seabird densities are generally lower in winter than in summer as a result of both a southward migration of some species and offshore dispersal of others. A variety of prey species are used by seabirds in the Gulf; of these, capelin, sand lance, and euphausiids are of greatest importance. Trophically, seabirds in the Gulf range from near primary con- sumers to third-order carnivores, ingesting an estimated 1,120,000 mt during the 120-day summer period.

Alaska↗
USGS1979

Tufted Puffins nesting in estuarine habitat

The Tufted Puffin ( Lunda cirrhata ) apparently has the most extensive breeding distribution of any North Pacific seabird, extending in the western North Pacific from Hokkaido to the north Chukotsk Peninsula on the Chukchi Sea, and in North America from Cape Lisburne on the Chukchi Sea, south to the Farallon Islands off central California (Udvardy 1963). Despite this wide breeding distribution, the reported nesting habitat is generally restricted to steep, rocky islands and continental headlands (see Dement’ev and Gladkov 1951, Kozlova 1957, Gabrielson and Lincoln 1959, Portenko 1973, Sealy 1973, and Sowls et al. 1978). Nests are typically excavated in steep slopes and/or on vegetated plateaus, well above normal tidal influence but occasionally within the spray or storm-wash zone. Nowhere has L. cirrhata or any other puffin species been reported to nest in a flat, estuarine habitat in substrate normally affected by tides during the breeding season. Portenko (1973: 137) refers to Tufted Puffins breeding on Alyumka Island in the Anadyr "estuary" (64°40'N, 177°37'E), but Alyumka Island is a rocky coastal island having immediate offshore waters between 3-18 m deep (A.A. Kistchinski, The Ringing Center, Moscow, and George Tyner, U.S. Defense Mapping Agency, pers. comm.). During the summers of 1976, 1977, and 1978, we found 14-18 pairs of Tufted Puffins nesting on 4 narrow sand islands (5-7 ha each) along the northcentral Alaska Peninsula at Nelson Lagoon (56°00'N, 161°10'W). As of June 1979, 25 active burrows had been reported there (Margaret R. Petersen, pers. comm.). The islands lie approximately 1.3 km from the Bering Sea coast and are protected from the sea by a long, narrow (0.5 kin) sand peninsula. The main deepwater channel in the lagoon, 3-7 m deep and 100-300 m wide at mean low water (MLW), separates the islands from the peninsula. The islands, which are free of permafrost, have a uniformly low profile with the highest elevation 1-2 m above mean high water (MHW) (Fig. 1). Each island is circumscribed by a gently sloping (<5°), narrow (5-15 m) sand/gravel beach that graduates at MLW to intertidal mud- and sandflats. These are extensive on the south and southeast sides (several hundred m) and relatively narrow (10-20 m) on the north and northwest or channel sides. The banks of each island are moderate to near vertical in slope. Puffin burrows face the channel, are located at or near the vegetation/beach interface, and extend into the bank horizontally or slightly downward. Beach rye ( Elymus arenarius mollis ) grows over most of each island and is used as nesting cover by several hundred Glaucous-winged Gulls ( Larus glaucescens ) and lesser numbers of Common Eiders ( Somateria mollissima v-nigra ). Predation by gulls on puffin eggs or chicks was not observed, nor did we see gulls rob food from adult puffins returning to their burrows from foraging in the Bering Sea (cf. Nettleship 1972). Puffins were never observed feeding in the lagoon.

Alaska↗