Publications

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The relationship between prairie grouse and land use was studied during the period 1964-71. Prairie chickens (Tympanuchus cupido) declined from 48 males in 1964 to none in 1971. Sharp-tailed grouse (Pedioecetes phasianellus) declined from 166 males in 1964 to 57 in 1971. These declines were related to the decline in vigor and eventual loss of Soil Bank habitat on the study area. Two new...

Livers of 42 pintail hens (Anas acuta) breeding in eastern North Dakota during the spring and early summer of 1969 and 1970 were analyzed for total mercury by the neutron activation technique. Mercury content on a wet weight basis ranged from 0.055 ppm to 9.512 ppm and averaged 0.888 ± 1.796 ppm (SD). Liver mercury levels of hens collected in early spring (prior to planting of crops)...

A method is described that provides a rapid and accurate analysis of habitat used by radio-equipped animals. The digitizer (basically an X-Y plotter in reverse) converts maps into digital form by describing each habitat unit as a polygon that closely approximates the actual shape of the unit. The coordinates of each polygon are then stored on magnetic tape. Habitat classification data...

In the summer of 1970, 648 (329 males and 319 females) hand-reared wild-strain mallards (Anas platyrhynchos) were banded and released at the Arrowwood National Wildlife Refuge, Edmunds, North Dakota. The females were also marked with numbered nasal saddles. Liberation was by the gentle release method, and no special effort was made to isolate or condition the ducklings prior to release...

Tests were conducted to determine whether changes that may occur in the chemical characteristics of stored oligotrophic waters collected on 15 sites in northeastern Minnesota were affected by chloroforming. Chloroform was added on site to one of each pair of samples to stabilize the organic content of the water by preventing biological decomposition. The samples were subsequently stored...

A classification of wetland plant communities was developed for a study area in north-central Minnesota in order to analyze data on waterfowl use of habitat that were gathered by radio telemetry. The classification employs features of several earlier classifications in addition to new classes for bogs and lakeshore communities. Brief descriptions are given for each community, and the...

Abstract has not been submitted

Abstract has not been submitted

Abstract has not been submitted

Long-range shooting at ducks and geese frequently results in a high crippling loss, unretrieved birds and frustrated hunters. A principal problem has been the general inability of hunters or observers to properly judge distance of birds. This paper describes a reasonably accurate method developed to determine shooting distances to geese. Two observers utilized transit-mounted 4X hunting...