Social and Behavioral Sciences Commons^™

The Comparison Of Usage And Availability Measurements For Evaluating Resource Preference, Douglas H. Johnson

USGS Northern Prairie Wildlife Research Center

Modern ecological research often involves the comparison of the usage of habitat types or food items to the availability of those resources to the animal. Widely used methods of determining preference from measurements of usage and availability depend critically on the array of components that the researcher, often with a degree of arbitrariness, deems available to the animal. This paper proposes a new method, based on ranks of components by usage and by availability. A virtue of the rank procedure is that it provides comparable results whether a questionable component is included or excluded from consideration. Statistical tests of significance …

Estimating Nest Success: The Mayfield Method And An Alternative, Douglas H. Johnson

USGS Northern Prairie Wildlife Research Center

Mayfield's method for calculating the success of a group of nests is examined in detail. The standard error of his estimator is developed. Mayfield's assumption that destroyed nests are at risk until the midpoint of the interval between visits leads to bias if nests are visited infrequently. A remedy is suggested, the Mayfield-40% method. I also present a competing model, which recognizes that the actual destruction date of a failed nest is unknown. Estimated daily mortality rates and standard errors are developed under this model. A comparison of the original Mayfield method, the Mayfield-40% method, and the new method, which …

Mathematics And Mallard Management, Lewis M. Cowardin, Douglas H. Johnson

USGS Northern Prairie Wildlife Research Center

Waterfowl managers can effectively use simple population models to aid in making management decisions. We present a basic model of the change in population size as related to survival and recruitment. A management technique designed to increase survival of mallards (Anas platyrhynchos) by limiting harvest on the Chippewa National Forest, Minnesota, is used to illustrate the application of models in decision making. The analysis suggests that the management technique would be of limited effectiveness. In a 2nd example, the change in mallard population in central North Dakota is related to implementing programs to create dense nesting cover with …

Age Determination Of Mallards, Gary L. Krapu, Douglas H. Johnson, Charles W. Dane

USGS Northern Prairie Wildlife Research Center

A technique for distinguishing adult from yearling wild mallards (Anas platyrhynchos), from late winter through the nesting season, was developed by applying discriminant analysis procedures to selected wing feather characters of 126 yearlings and 76 adults (2-year-olds) hand-reared from wild eggs during 1974, 1975, and 1977. Average values for feather characters generally increased as the birds advanced from yearlings to adults. Black-white surface area of greater secondary covert 2 was the single most reliable aging character identified during the study. The error rate was lowest in females (3%) when discriminant functions were used with measurements of primary 1 …

Interpreting The Results Of Nesting Studies, Harvey W. Miller, Douglas H. Johnson

USGS Northern Prairie Wildlife Research Center

Nesting studies are used to assess the production of birds and to evaluate nesting habitats. Most such studies involve finding nests in a given area and subsequently determining the proportion that hatched. Unfortunately, the results are often biased by unrecognized differences in the probabilities of finding successful and unsuccessful nests. The observed hatch rates of 1,900 nests of blue-winged teal (Anas discors) are presented to illustrate the relationship of hatch rates to time remaining until the nests should hatch. The Mayfield method of correcting for these biases is illustrated. Other examples demonstrate the possible effects of sampling procedures …

Foods Of Juvenile, Brood Hen, And Post-Breeding Pintails In North Dakota, Gary Krapu, George Swanson

USGS Northern Prairie Wildlife Research Center

The Pintail (Anas acuta) is a common to abundant nesting species in North Dakota, becoming more numerous during years of favorable water conditions and less so during drought. Stewart and Kantrud (1974) estimated breeding-populations of 304,000, 111,000 and 379,000 pairs in the Prairie Pothole Region of North Dakota during 1967-69, respectively. We studied food habits of juvenile and adult Pintails during the brood-rearing and post-breeding periods in North Dakota to learn their food requirements during these phases of the life cycle. Food habits of flightless juveniles have been studied in Alberta (Sugden 1973) and limited information on downy …

Use Of Natural Basin Wetlands By Breeding Waterfowl In North Dakota, Harold A. Kantrud, Robert E. Stewart

USGS Northern Prairie Wildlife Research Center

Use of basin wetlands by breeding populations of 12 species of waterfowl was investigated in 1965 and during 1967-69 throughout the prairie pothole region of North Dakota. Data were obtained primarily by random sampling techniques. Of the total population occupying natural basin wetlands 55 percent occupied seasonal and 36 percent occupied semipermanent wetlands. Seasonal wetlands contained 60 percent of the population of dabbling ducks, while semipermanent wetlands supported 75 percent of the population of diving ducks. On basins with ponded water, highest concentrations of breeding pairs occurred on temporary, seasonal, and semipermanent wetlands; moderate concentrations were recorded on ephemeral, fen, …

Pintail Reproduction Hampered By Snowfall And Agriculture, Gary Krapu

USGS Northern Prairie Wildlife Research Center

The reproductive strategy of the Pintail (Anas acuta) shows several adaptations to the semi-arid variable climate of the prairie pothole region of north central North America where the species is a common breeder. By nesting early and using temporary and seasonal water areas replenished by snow melt waters or early spring rains, the species has successfully occupied broad areas containing limited permanent and semi-permanent water. The Pintail is prone to select new breeding grounds during periods of drought. Smith (J. Wildl. Manage. 34:9@-946, 19701 has shown that part of the population moves northward from the prairies and parklands …

A Hematologic Survey Of Captive Waterfowl, Hazel Shave, Valeria Howard

USGS Northern Prairie Wildlife Research Center

Hematologic parameters were studied in giant Canada geese (Branta canadensis Maxima), mallard ducks (Anas platyrhynchos platyrhynchos) and various species of diving ducks at seasonal intervals throughout the year. Highest values for packed cell volume, hemoglobin content and erythrocyte counts were found in the winter and pre-nesting periods. Mean corpuscular volume and mean corpuscular hemoglobin varied inversely with these values.

Spring Mortality Of Insectivorous Birds In Southern Manitoba, Jerome R. Serie, Robert E. Jones

USGS Northern Prairie Wildlife Research Center

Migrating passerines frequently encounter adverse weather during their northward movements in early spring. Inclement weather often causes temporary halt of migrating passerines short of their destinations (Curtis 1969). In May 1974, such a grounding of spring migrants occurred in southwestern Manitoba due to unseasonable weather. Many insectivorous birds became weakened or died of starvation as a result of exposure to low temperatures, depletion of fat reserves, and lack of available food.

Arrival of Spring Migrants

The first large influx of insectivorous birds, mainly Myrtle (Dendroica coronado coronata) and Yellow (Dendroica petechia) Warblers, was noted on 19 …

Fatal Pox Infection In A Rough-Legged Hawk, G. L. Pearson, D. A. Pass, E. C. Beggs

USGS Northern Prairie Wildlife Research Center

Natural pox infection occurred in a free-living rough-legged hawk (Buteo lagopus) in northeastern North Dakota. Gross, histological and electron microscopic findings were typical of pox infection, and characteristic lesions developed in red-tailed hawks (Buteo jamaicensis) but not in great horned owls (Bubo virginianus) following inoculation with case material. Death of the rough-legged hawk was attributed to starvation resulting from inability to capture prey and to blood loss from foot lesions.

Age Determination Of Female Redhead Ducks, Charles W. Dane, Douglas H. Johnson

USGS Northern Prairie Wildlife Research Center

Eighty-seven fall-collected wings from female redhead ducks (Aythya americana) were as- signed to the adult or juvenile group based on "tertial" and "tertial covert" shape and wear. To obtain spring age-related characters from these fall-collected groupings, we considered parameters of flight feathers retained until after the first breeding season. Parameters measured included: markings on and width of greater secondary coverts, and length, weight, and diameter of primary feathers. The best age categorization was obtained with discriminant analysis based on a combination of the most accurately measured parameters. This analysis, applied to 81 wings with complete measurements, resulted in …

Breeding Waterfowl Populations In The Prairie Pothole Region Of North Dakota, Robert E. Stewart, Harold A. Kantrud

USGS Northern Prairie Wildlife Research Center

The pothole areas within the glaciated, northern prairies and adjoining parklands of south-central Canada and north-central United States are the principal breeding grounds for many species of North American ducks. Millions of pairs, including dabbling ducks (Anatinae) and diving ducks (Aythyinae and Oxyurinae), resort here for nesting each year. These populations are characterized by instability. In response to the variable climatic conditions of this region and their effect on wetland habitats, the numbers of breeding pairs often fluctuate greatly from year to year. In addition, regional populations are influenced by man. Factors that are especially important in this regard include …

Advantages In Mathematically Weighting Waterfowl Food Habits Data, George A. Swanson, Gary L. Krapu, James C. Bartonek, Jerome R. Serie, Douglas H. Johnson

USGS Northern Prairie Wildlife Research Center

The relative importance of various foods occurring in the diet of blue-winged teal (Anas discors), pintail (A. acuta), and gadwall (A. strepera) breeding in south-central North Dakota and lesser scaup (Aythya affinis) breeding in the vicinity of Great Slave Lake, Northwest Territories, are com- pared by the aggregate volume and aggregate percent methods. Advantages of the aggregate percent method are discussed in relation to the information presented.

Estimating Survival Rates From Banding Of Adult And Juvenile Birds, Douglas H. Johnson

USGS Northern Prairie Wildlife Research Center

The restrictive assumptions required by most available methods for estimating survival prob- abilities render them unsuitable for analyzing real banding data. A model is proposed which allows survival rates and recovery rates to vary with the calendar year, and also allows juveniles to have rates different from adults. In addition to survival rates and recovery rates, the differential vulnerability factors of juveniles relative to adults are estimated. Minimum values of the variances of the estimators are also given. The new procedure is applied to sets of duck and goose data in which reasonably large numbers of adult and juvenile birds …

An Incident Of Fenthion Mosquito Control And Subsequent Avian Mortality, Robert Seabloom, Gary Pearson, Lewis Oring, James Reilly

USGS Northern Prairie Wildlife Research Center

Mass mortality among migratory birds at Grand Forks, North Dakota, was attributed to a mosquito control operation employing the insecticide fenthion. The factors involved may have included the toxicity of the pesticide for birds, the method of application and coincidence with the peak of the spring warbler migration.

Ecological Distribution Of Breeding Waterfowl Populations In North Dakota, Robert E. Stewart, Harold A. Kantrud

USGS Northern Prairie Wildlife Research Center

The distribution of breeding waterfowl populations on various wetland habitat types was investigated in North Dakota during 1967-69. Data were obtained by stratified random sampling techniques. The total wetland acreage in North Dakota was estimated to be about 3.2 million acres. Natural basin wetlands comprised about 77 percent of the acreage and 91 percent of the number of wetlands in the state and were utilized by about 76 percent of the state's breeding duck population. Among the four biotic regions of the state, numerical and areal composition of wetlands varied considerably. Natural basin wetlands varied from a low of about …

Racial Composition Of Migrant Populations Of Sandhill Cranes In The Northern Plains States, Douglas H. Johnson, Robert E. Stewart

USGS Northern Prairie Wildlife Research Center

During recent years, there has been increasing pressure to expand hunting seasons on Sandhill Cranes (Grus canadensis) in the northern plains states. Hunters desire to take advantage of the opportunity presented by the sizable flocks of this large bird in this area. Prior to passage of the Migratory Bird Treaty Act in 1918, the Sandhill Crane was hunted and considered to have high sporting and eating qualities. In addition, complaints have been received from farmers regarding grain crop depredations by cranes. It has been suggested (Boeker et al., 1961:16) that flocks of cranes would be more widely dispersed …

Population Estimates Of Breeding Birds In North Dakota, Robert E. Stewart, Harold A. Kantrud

USGS Northern Prairie Wildlife Research Center

Reasonably accurate measurements of breeding bird populations on large land areas are needed if the overall effects of man's impact on the environment are to be measured and understood. Through use of these data, we will be able to detect the average response of these populations to generalized environmental changes caused by diverse and widespread land-use practices. As this kind of information becomes available, it will serve as the basis for developing appropriate management programs for the purpose of maintaining or increasing breeding bird populations.

Aspergillosis In Wintering Mallards, Gary Pearson

USGS Northern Prairie Wildlife Research Center

Losses among mallards (Anas platyrhynchos ) wintering on a seepage ditch below the Garrison Dam on the Missouri River at Riverdale, North Dakota, were reported on February 24, 1968. In early February, while conducting their annual winter banding operation, personnel of the North Dakota Game and Fish Department observed approximately 1.000 mallards on the ditch. Approximately 200 mallards were banded after being captured in a walk-in trap baited with corn and wheat located on the bank of the ditch. Snow covered the area and caused the ducks to concentrate at the bait site from the time of the banding …