SEARCH · USGS Science

Results for “Waterfowl”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,099 records · Page 61Linked to original sources

USGS2010

Evaluation of an aerial survey to estimate abundance of wintering ducks in Mississippi

Researchers have successfully designed aerial surveys that provided precise estimates of wintering populations of ducks over large physiographic regions, yet few conservation agencies have adopted these probability-based sampling designs for their surveys. We designed and evaluated an aerial survey to estimate abundance of wintering mallards ( Anas platyrhynchos ), dabbling ducks (tribe Anatini) other than mallards, diving ducks (tribes Aythini, Mergini, and Oxyurini), and total ducks in western Mississippi, USA. We used design-based sampling of fixed width transects to estimate population indices ( Î ), and we used model-based methods to correct population indices for visibility bias and estimate population abundance ( N̂ ) for 14 surveys during winters 2002–2004. Correcting for bias increased estimates of mallards, other dabbling ducks, and diving ducks by an average of 40–48% among all surveys and contributed 48–61% of the estimated variance of N̂ . However, mean-squared errors were consistently less for N̂ than Î . Estimates of N̂ met our goals for precision (CV ≤ 15%) in 7 of 14 surveys for mallards, 5 surveys for other dabbling ducks, no surveys for diving ducks, and 10 surveys for total ducks. Generally, we estimated more mallards and other dabbling ducks in mid- and late winter (Jan–Feb) than early winter (Nov–Dec) and determined that population indices from the late 1980s were nearly 3 times greater than those from our study. We developed a method to display relative densities of ducks spatially as an additional application of survey data. Our study advanced methods of estimating abundance of wintering waterfowl, and we recommend this design for continued monitoring of wintering ducks in western Mississippi and similar physiographic regions.

Mississippi↗

USGS1978

Changes in submerged aquatic macrophyte populations at the head of Chesapeake Bay, 1958-1975

Submerged aquatic plant populations in the Susquehanna Flats of the Chesapeake Bay were followed for 18 years. An exotic species, eurasian water milfoil, Myriophyllum spicatum , increased dramatically from 1958 to 1962; at the same time the dominant native species declined. After 1962, milfoil populations declined and the native rooted aquatics gradually began to return to their former levels. In the late 1960's all species declined and in 1972 almost disappeared from the Susquehanna Flats. These fluctuations may have been related to several interrelated environmental factors in the Chesapeake Bay, including tropical storms, turbidity, salinity and disease. The utilization of the Susquehanna Flats by waterfowl appears to be related to the abundance and species composition of the submerged macrophytes present.

Maryland, Virginia↗

USGS2000

Geographic signatures of North American West Coast estuaries

West Coast estuaries are geologically young and composed of a variety of geomorphological types. These estuaries range from large fjords to shallow lagoons; from large to low freshwater flows. Natural hazards include E1 Niños, strong Pacific storms, and active tectonic activity. West Coast estuaries support a wide range of living resources: five salmon species, harvestable shellfish, waterfowl and marine birds, marine mammals, and a variety of algae and plants. Although populations of many of these living resources have declined (salmonids), others have increased (marine mammals). West Coast estuaries are also centers of commerce and increasingly large shipping traffic. The West Coast human population is rising faster than most other areas of the U.S. and Canada, and is distributed heavily in southern California, the San Francisco Bay area, around Puget Sound, and the Fraser River estuary. While water pollution is a problem in many of the urbanized estuaries, most estuaries do not suffer from poor water quality. Primary estuarine problems include habitat alterations, degradation, and loss; diverted freshwater flows; marine sediment contamination; and exotic species introductions. The growing West Coast economy and population are in part related to the quality of life, which is dependent on the use and enjoyment of abundant coastal natural resources.

British Columbia;California;Oregon;Washington↗

USGS1990

Extra-pair copulations in Black Brant

Monogamy is the primary mating system among waterfowl, but extra-pair copulations (EPCs) have been documented in at least 39 species (McKinney et al. 1983). Extra-pair copulations occur in most Holarctic species of dabbling ducks ( Anas spp.), but have been recorded in only three species of geese: Lesser Snow Geese, Chen caerulescens caerulescens (Mineau and Cooke 1979a), Ross’ Geese, C. rossii (J. Ryder in McKinney et al. 1984), and Greater White-fronted Geese, Anser albifrons frontalis (C.R. Ely, pers. comm.). In colonial Lesser Snow Geese, the close proximity of nesting conspecifics may enable males to pursue EPCs as a secondary reproductive strategy (Mineau and Cooke, 1979a, 1979b). Copulatory behavior of other geese has not been studied in sufficient detail to permit comparison with Lesser Sone Geese. Here we report on timing and rates of pair copulations (PCs) and EPCs, and describe behaviors associated with EPCs in colonially nesting Black Brant ( Branta bernicla nigricans ).

The Condor↗

USGS1987

Aggressive encounters between tundra swans and greater white-fronted geese during brood rearing

Interspecific aggression in waterfowl (Anatidae) is relatively common (McKinney 1965; Kear 1972; Savard 1982, 1984), but interactions leading to mortality of one of the combatants are rarely-observed in the wild. A recent debate (Livezey and Humphrey 1985a, 1985b; Nuechterlein and Storer 1985a, 1985b; Murray 1985) has centered on the proximate and ultimate causes of interspecific territoriality and killing in steamer-ducks ( Tachyeres spp.), a group of large-bodies antids. We report here aggressive encounters between Greater White-fronted Geese ( Anser albifrons ) and Tundra Swans ( Cygnus columbianus ) during brood rearing on the Yukon-Kuskokwim Delta, Alaska, which on two occasions resulted in the death of a White-fronted Goose gosling.

Alaska↗

USGS1997

Relative costs of prebasic and prealternate molts for male blue-winged teal

We compared masses of definitive basic and alternate plumages of male Blue-winged Teal ( Anas discors ) to evaluate the hypothesis that nutritional investments in basic and alternate plumages are related to the duration that plumages are worn and to assess the relative costs of prebasic and prealternate molts. Because these plumages are worn by males for approximately equal durations, we predicted that masses of the basic and alternate body plumages would be similar. To assess nutritional stress ( demands greater than available resources ) associated with molt, we examined the relation between remigial length and structural size and compared predicted and observed plum-age masses of Blue-winged Teal and other ducks. If birds were nutritionally challenged during remigial molt, then we predicted remigial length would be influenced by nutrition rather than size, and remigial length and size would be unrelated. Alternate body plumage of male Blue-winged Teal weighed about 10% more than the basic body plumage; however, masses of both plumages were less than that predicted on the basis of lean body mass. We argue that deviations between observed and predicted plumage masses were related to factors other than nutrition. Further, remigial lengths were significantly, albeit weakly, related to structural size. We therefore concluded that, although the potential for molt-induced stress may be greatest in small-bodied waterfowl species, there was no clear evidence that molting male Blue-winged Teal were nutritionally stressed.

Louisiana↗

USGS1999

Time of day of ovulation by three duck species in subarctic Alaska

I examined variation in ovulation times of Northern Pintails (Anas acuta), American Wigeon (A. americana), and Lesser Scaup (Aythya affinis) breeding in subarctic Alaskan wetlands. Ovulation times and, by extension, egg-laying times were highly variable in all three species, with ovulations occurring during all hours of the day. Only Lesser Scaup demonstrated a morning peak in ovulations, within a broad range of ovulation times. Lack of a distinct time of day of ovulation suggests that fitness is not related to egg-laying time for these species, particularly at subarctic latitudes with nearly perpetual daylight. Egg-laying interval may have more adaptive significance than egg-laying time for these species. Ovulation intervals were estimated to be approximately 24 hr, which is short relative to the range of intervals documented in birds, despite high energetic and nutritional costs of egg formation in these species. Evidence of approximately 24-hr ovulation intervals, particularly in the absence of a distinct time of day for egg laying, supports hypotheses that a shortened period of egg production in waterfowl may have selective advantage due to reduction in the period of nest exposure to predation, earlier hatch dates, reduced hatch asynchrony, or improved viability of early-laid eggs.

Condor↗

USGS1980

Epizootic of coccidiosis in free-flying lesser scaup (Aythya affinis)

A coccidiosis epizootic has occurred in lesser scaup ( Aythya affinis ) at Bluestem Reservoir in eastern Nebraska during the spring in each of three recent years: 1976-1978. Losses peaked during the period from mid-March through April. As much as 29% of the peak population of scaup using the reservoir died. Necropsies of 72 of the nearly 1390 scaup that died revealed destruction and sloughing of the intestinal mucosa and associated hemorrhaging. Fibrinonecrotic cores were frequently found in the intestinal lumens. Scrapings from the intestinal mucosal contained massive numbers of oocysts of the coccidian Eimeria aythyae . This is the first report of recurrent epizootics of coccidiosis in freeflying waterfowl.

Nebraska↗

USGS1988

Characterization of an avian cholera epizootic in wild birds in western Nebraska

Avian cholera killed an estimated 2500 birds in western Nebraska and eastern Wyoming from 28 November 1985 to late January 1986. Wild mallards (Anas platyrhynchos) suffered the most losses. Other wild waterfowl, wild turkeys (Meleagris gallopavo), a few domestic fowl, and a bald eagle (Haliaeetus leucocephalus) also died. Pasteurella multocida serotype 1 was the predominant isolate from these carcasses. Cold, wet weather persisted throughout the outbreak, but daily losses in the flock of 50,000 mallards using the area were low. Pasteurella multocida was isolated from nasal swabs of 35 of 37 cattle from a feedlot in which many of these mallards were feeding. Eighty percent of the cattle isolates had antigenic characteristics of serotype 3 or serotype 3 with cross-reactivity. Isolates from wild mallards, wild turkeys, and the bald eagle were virulent to game-farm mallards when inoculated subcutaneously, but P. multocida isolates from cattle were not.

Nebraska, Wyoming↗

USGS1978

A log-linear model approach to estimation of population size using the line-transect sampling method

The technique of estimating wildlife population size and density using the belt or line-transect sampling method has been used in many past projects, such as the estimation of density of waterfowl nestling sites in marshes, and is being used currently in such areas as the assessment of Pacific porpoise stocks in regions of tuna fishing activity. A mathematical framework for line-transect methodology has only emerged in the last 5 yr. In the present article, we extend this mathematical framework to a line-transect estimator based upon a log-linear model approach.

Ecology↗

USGS1966

Insecticide contaminations in wetland habitats and their effects on fish- eating birds

An unusual mortality of fish-eating birds occurred at the Tule Lake National Wildlife Refuge in California between 1960 and 1962. Over 1100 dead birds of ten species were found during that period. Investigations of the mortality indicated that birds died as a result of their exposure to toxaphene, which was applied to adjoining agricultural areas, transported to the refuge in waste irrigation water, and accumulated in fish eaten by the birds. Toxaphene was used in agriculture for only 3 years, 1958-60, and by 1962 residues were no longer found in the marsh habitat. However, results also showed that a potentially hazardous contamination of DDT and its metabolites was present in the birds and the environment. Studies were, therefore, continued to determine the food-chain relationships of DDT in marsh ecosystems, and the effects of the insecticide on birds. Sampling for insecticide residues was undertaken at four waterfowl refuges, each representing a somewhat different set of environmental conditions. DDT residues in water at each refuge were found to be relatively low, but filtered samples showed that residues in suspended material were 10 000 to 20 000 times as great as those in the filtrate. Much of the suspended material was organic matter, which is an important source of energy for the ecosystems. In environments with invertebrates, DDT residues were relatively low in sediments and high in fish, while residues in vegetation were highest where invertebrates were absent. Results suggest that organic materials and invertebrates can be important factors in determining the fate and involvement of insecticides in aquatic environments. Studies of the movements, exposure to pesticides, productivity, and longevity of individuals in three nesting colonies of White Pelicans were begun in 1962 to depict the relationships of pesticides to a migratory population of birds dependent upon wetland habitats. To date there is no evidence that the exposure of pelicans to DDT is influencing the population dynamics of the birds.

California, Oregon↗

USGS2007

The R3/R5 impoundment study: A large-scale management experiment

Managed wetlands provide a broad spectrum of resources to migratory waterbirds (shorebirds, wading birds, and waterfowl) throughout the annual cycle. Successful conservation and management of waterbirds depends on integrated approaches that (1) incorporate larger spatial and temporal scales than traditional approaches to wetland management, and (2) use experimental designs to reduce uncertainty about the response of the systems to management. In a previous experiment on USFWS National Wildlife Refuges in the Northeast, we explored the effects of water-level management on migratory shorebirds in spring. We documented regional patterns of shorebird use of Refuge wetlands and showed that across the region, a slow drawdown was superior to 2 alternatives. USGS and USFWS have now cooperatively undertaken an expanded study focusing on 3 waterbird guilds in the context of the complete annual cycle and over a larger spatial extent. For this 3-yr study, now in its first year, 2 impoundments were selected at each of 23 NWRs across the Northeast and Upper Midwest Regions. Two experimental treatments (annual water regimes focused on early-season or late-season drawdowns) are being applied each year in a cross-over design. This experimental design will increase our understanding of cross-seasonal interactions which result from specific hydrologic regimes aimed at a particular waterbird guild. Monitoring will allow waterbird responses to be linked with direct effects of water management on plant and invertebrate populations. Results of this large-scale experiment will be used to motivate formal adaptive management of wetlands and waterbirds at refuges following completion of this experiment.

Conference Paper↗

USGS1989

Model-based estimates of annual survival rate are preferable to observed maximum lifespan statistics for use in comparative life-history studies

Estimates of longevity are available for many animals, and are commonly used in comparative life-history analyses. We suggest that annual survival rate is a more appropriate life history parameter for most comparative life history analyses. Observed maximum lifespans estimate complicated functions of survival and sampling probabilities. Annual survival rate estimates derived from modern band-recovery statistical procedures are becoming available for a variety of organisms. We compiled annual survival rate estimates and observed maximum longevities derived from band recovery data for North American waterfowl. Observed maximum longevities were not correlated with the annual survival rate estimates and appear to be unstable over time. We recommend that observed maximum lifespans not be used in life history analyses.

Oikos↗

USGS1967

Stump and tree nesting by mallards and black ducks

Studies conducted 1961-65 at the Montezuma National Wildlife Refuge in New York demonstrated that mallards ( Anas platyrhynchos ) and black ducks ( Anas rubripes ) make extensive use of stumps and dead snags for nest sites. Nest densities in timbered habitats compared favorably with those in untimbered habitats. Nest success was generally higher in timbered than in untimbered areas, except for a newly flooded impoundment where nest success was poor. A simple artificial nest structure was used to increase the number of available nest sites in some of the timbered habitats. Development of stump-nesting populations of ducks may furnish a means of increasing waterfowl production in forested areas.

New York↗

USGS1966

Fall food habits of ducks near Santee Refuge, South Carolina

During the 1961 waterfowl hunting season, 360 stomachs of 10 duck species were collected from hunters near the Santee National Wildlife Refuge, Lake Marion, South Carolina. Based on percentage of total volume, 20 of the most important foods are listed. The six most important duck species in the kill were: mallard ( Anas platyrhynchos ), wood duck ( Aix sponsa ), widgeon ( Mareca americam ), pintail ( Anas acuta ) , black duck ( Anas rubripes ) , and green-winged teal ( Anas carolinensis ). Six plant species made up 5 percent or more of the total volume of food items found in the stomachs of all ducks. Only seeds of oaks ( Quercus sp.), corn, sweet gum ( Liquidambar Styraciflua ), and buttonbush ( Cephalanthus occidentalis ) were consumed. Some seed, but mostly the vegetative portions of hydrochloa ( Hydrochloa carolinensis ) and only the vegetative portions of southern rice cutgrass ( Leersia hexandra ) were taken. The more important game ducks concentrated on the refuge farmlands when water levels were below 72 feet mean sea level (msl). When levels reached 75 feet msl, natural foods became available, ducks dispersed from refuge areas, and hunting success increased greatly.

South Carolina↗

USGS1972

Some effects of aldrin-treated rice on Gulf Coast wildlife

Wildlife casualties from aldrin-dieldrin poisoning are associated with the planting of aldrin-treated rice seed along the Texas Gulf Coast. The fulvous tree duck ( Dendrocygna bicolor ), which depends on the rice field habitats and is highly susceptible to aldrin-dieldrin poisoning, is suffering a serious population decline in that area. Dead waterfowl, shorebirds, and passerines were collected on study areas in Wharton, Brazoria, and Chambers counties, Texas, from 1967 through 1971. Residues of aldrin or dieldrin were found in all samples of bird casualties and in all eggs, scavengers, predators, fish, frogs, invertebrates, and soils. Fulvous tree ducks appeared to be less resistant to aldrin than other ducks. Dieldrin residues in brains of dead fulvous tree ducks were low, but whole-body residues were as high as 16 ppm. Brains of other dead ducks and geese averaged 10 ppm dieldrin. Some dead birds were exposed by eating treated rice seed, but many dead birds with high dieldrin residues were species that feed largely on invertebrates. Although soil residues were low, snails and crayfish contained enough aldrin and dieldrin (average 9.5 ppm) to account for deaths in birds that fed heavily on these invertebrates over a period of time. When fulvous tree ducks were penned for 3 days in fields aerially planted with treated seed, 3 of 10 birds died with brain residues of 2.5, 2.9, and 6.8 ppm dieldrin, and others were intoxicated. None of eight died, and some gained weight, when penned in fields planted with untreated seed. This study adds further evidence for the suspected lethal effects of aldrin-treated rice seed on wild birds and other wildlife in rice field habitats.

Texas↗

USGS1970

Correction of bias in belt transect studies of immotile objects

Unless a correction is made, population estimates derived from a sample of belt transects will be biased if a fraction of, the individuals on the sample transects are not counted. An approach, useful for correcting this bias when sampling immotile populations using transects of a fixed width, is presented. The method assumes that a searcher's ability to find objects near the center of the transect is nearly perfect. The method utilizes a mathematical equation, estimated from the data, to represent the searcher's inability to find all objects at increasing distances from the center of the transect. An example of the analysis of data, formation of the equation, and application is presented using waterfowl nesting data collected in Colorado.

Colorado↗

USGS1975

Some nutritional aspects of reproduction in prairie nesting pintails

The nutritional significance of invertebrate foods in the diet of breeding hen waterfowl during the period of egg formation is discussed. Proximate, elemental, and amino acid analyses of the principal foods consumed by hen pintails ( Anas acut ) during the nesting season indicate the animal foods selected are rich sources of protein and calcium, whereas plant foods tested were low in protein, particularly in the essential amino acids lysine and methionine. Calcium content in major plant foods was far below needs considered adequate for egg production. Studies with penned, hand-reared pintails indicated the inadequacy of wheat as the dietary staple during breeding. Egg production among pairs on the control diet differed significantly from that of the wheat plus oystershell (P < 0.05) and wheat (P < 0.01) diets. Pairs fed wheat during the breeding period experienced nearly complete reproductive failure. The poor reproductive response among hens on the diet of wheat plus oystershell suggested that calcium availability was not the only factor limiting productivity.

Journal of Wildlife Management↗