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H.K. Nelson

Publications and source records attributed to H.K. Nelson.

10 recordsLinked to original sources
USGS1973

Mercury residues in pintails breeding in North Dakota

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) were significantly lower than those of hens taken late in the nesting season ( P < 0.01). Mercury residues among prelaying, laying, and postlaying groups collected following the onset of spring planting did not differ significantly ( P > 0.05). Albumen mercury residue was correlated with liver mercury content (r = 0.756, P < 0.05). Mercury content in livers of five wild juveniles averaged 0.123 ± 0.074 ppm.

North Dakota↗
USGS1968

Effect of predator reduction on waterfowl nesting success

A 6-year study to determine the effect of nest-predator removal on waterfowl nesting success was conducted at the Agassiz National Wildlife Refuge in northwestern Minnesota from 1959 through 1964. Predators were removed from the west side of the Refuge while the east side served as a control area. At the end of 3 years, these areas were reversed to reduce the effects of environmental influences. The effect of predator removal was measured by a simulated nest study to determine predation pressure, a check of natural nest success, and weekly breeding pair and brood counts. Results indicated that 60 percent more Class I ducklings were produced on the units where predator control was conducted. Until more is known, reduction of predators to increase waterfowl nesting success should be limited to intensively managed production areas where substantial nest losses are demonstrated.

Minnesota↗
USGS1952

Hybridization of Canada geese with blue geese in the wild

While carrying out hunter bag checks in the vicinity of Sand Lake National Wildlife Refuge, Columbia, South Dakota, during the 1950 waterfowl hunting season, the author examined two adult male geese which proved to be crosses between one of the smaller Canada Geese (possibly Richardson's Goose, Branta canadensis hutchinsi ) and the Blue Goose, Chen caerulescens .

South Dakota↗