Gary Krapu, PhD
Dr. Gary Krapu is a Wildlife Biologist (Emeritus) at the USGS Northern Prairie Wildlife Research Center in Jamestown, North Dakota.
Science and Products
Filter Total Items: 105
Effects of weather on habitat selection and behavior of mallards wintering in Nebraska
Sex and age ratios, habitat selection, spatial characteristics, and time budgets of Mallards (Anas platyrhynchos) wintering on the Platte River in south central Nebraska were studied from mid-December to early April 1978-1980. The proportion of females and subadults in the population increased substantially from a cold to a mild winter. Radio-tagged Mallards shifted from riverine to canal roost si
Authors
Dennis G. Jorde, G.L. Krapu, R.D. Crawford, M.A. Hay
Feeding ecology of mallards wintering in Nebraska
Food use by mallards (Anas platyrhynchos) wintering on the Platte River in south central Nebraska was determined from mid-December to early March 1978-80. Mallards foraged in river channels, irrigation drainage canals, and agricultural areas. Plant matter formed 97% of the diet (dry weight) and diets did not vary between sexes (P > 0.05). Waste corn was the principal food consumed and formed 46 an
Authors
Dennis G. Jorde, G.L. Krapu, R.D. Crawford
The effect of variable spring water conditions on mallard reproduction
Mallard (Anas platyrhynchos) breeding densities in the prairie pothole habitat of eastern North Dakota during 1961-1980 varied from 2.28 birds/km2 in 1977 to 9.47 birds/km2 in 1963 and were correlated with pond abundance (r = 0.543, P < 0.05). The number of basins used by pairs declined with drought, as did home-range size. Nesting activity also varied with the number of ponds holding water/km2, r
Authors
Gary L. Krapu, A.T. Klett, Dennis G. Jorde
[Book review] Waterfowl ecology and management: Selected readings
This book is a compilation of papers from the extensive and varied published literature on the ecology and management of waterfowl. The 125 technical papers reprinted in this book are arranged in eight major sections and are from 21 journals, government reports, several books, and proceedings of symposia and annual conferences. The most frequent sources of papers are The Journal of Wildlife Manage
Authors
Gary L. Krapu
[Book review] Ducks, geese and swans of North America
This is the 3rd edition of the classic work "The Ducks, Geese and Swans of North America," which was first published in December 1942. The original edition was authored by Francis C. Kortright with color plates by T. M. Shortt. An authoritative reference on North American waterfowl for many years, the book had become outdated as a result of major advances in the field of waterfowl biology. The ne
Authors
Gary L. Krapu
The role of nutrient reserves in mallard reproduction
Mallard (Anas platyrhynchos) populations breeding in temperate North America obtain a significant part of the energy and lipid requirements of reproduction at sites occupied prior to arrival on the breeding grounds. Protein for egg formation, however, is obtained principally from the diet during the nesting period. Both sexes arrive heavy and fat in North Dakota but experience substantial weight l
Authors
Gary L. Krapu
The importance of shallow wetlands to waterfowl production
Abstract has not been submitted
Authors
G.L. Krapu
Marsh nesting by mallards
Nest-site selection by mallard (Anas platyrhynchos) hens was studied on a 52-km2, privately owned area in the Missouri Coteau of south-central North Dakota during 1974-77. Sixty-six percent of 53 nests initiated by radio-marked and unmarked hens were in wetlands in dense stands of emergent vegetation and usually within 50 m of the wetland edge. These findings and other sources of information sugge
Authors
G.L. Krapu, L.G. Talent, T.J. Dwyer
Use of prairie pothole habitat by breeding mallards
Abstract has not been submitted
Authors
T.J. Dwyer, G.L. Krapu, D.M. Janke
Science and Products
Filter Total Items: 105
Effects of weather on habitat selection and behavior of mallards wintering in Nebraska
Sex and age ratios, habitat selection, spatial characteristics, and time budgets of Mallards (Anas platyrhynchos) wintering on the Platte River in south central Nebraska were studied from mid-December to early April 1978-1980. The proportion of females and subadults in the population increased substantially from a cold to a mild winter. Radio-tagged Mallards shifted from riverine to canal roost si
Authors
Dennis G. Jorde, G.L. Krapu, R.D. Crawford, M.A. Hay
Feeding ecology of mallards wintering in Nebraska
Food use by mallards (Anas platyrhynchos) wintering on the Platte River in south central Nebraska was determined from mid-December to early March 1978-80. Mallards foraged in river channels, irrigation drainage canals, and agricultural areas. Plant matter formed 97% of the diet (dry weight) and diets did not vary between sexes (P > 0.05). Waste corn was the principal food consumed and formed 46 an
Authors
Dennis G. Jorde, G.L. Krapu, R.D. Crawford
The effect of variable spring water conditions on mallard reproduction
Mallard (Anas platyrhynchos) breeding densities in the prairie pothole habitat of eastern North Dakota during 1961-1980 varied from 2.28 birds/km2 in 1977 to 9.47 birds/km2 in 1963 and were correlated with pond abundance (r = 0.543, P < 0.05). The number of basins used by pairs declined with drought, as did home-range size. Nesting activity also varied with the number of ponds holding water/km2, r
Authors
Gary L. Krapu, A.T. Klett, Dennis G. Jorde
[Book review] Waterfowl ecology and management: Selected readings
This book is a compilation of papers from the extensive and varied published literature on the ecology and management of waterfowl. The 125 technical papers reprinted in this book are arranged in eight major sections and are from 21 journals, government reports, several books, and proceedings of symposia and annual conferences. The most frequent sources of papers are The Journal of Wildlife Manage
Authors
Gary L. Krapu
[Book review] Ducks, geese and swans of North America
This is the 3rd edition of the classic work "The Ducks, Geese and Swans of North America," which was first published in December 1942. The original edition was authored by Francis C. Kortright with color plates by T. M. Shortt. An authoritative reference on North American waterfowl for many years, the book had become outdated as a result of major advances in the field of waterfowl biology. The ne
Authors
Gary L. Krapu
The role of nutrient reserves in mallard reproduction
Mallard (Anas platyrhynchos) populations breeding in temperate North America obtain a significant part of the energy and lipid requirements of reproduction at sites occupied prior to arrival on the breeding grounds. Protein for egg formation, however, is obtained principally from the diet during the nesting period. Both sexes arrive heavy and fat in North Dakota but experience substantial weight l
Authors
Gary L. Krapu
The importance of shallow wetlands to waterfowl production
Abstract has not been submitted
Authors
G.L. Krapu
Marsh nesting by mallards
Nest-site selection by mallard (Anas platyrhynchos) hens was studied on a 52-km2, privately owned area in the Missouri Coteau of south-central North Dakota during 1974-77. Sixty-six percent of 53 nests initiated by radio-marked and unmarked hens were in wetlands in dense stands of emergent vegetation and usually within 50 m of the wetland edge. These findings and other sources of information sugge
Authors
G.L. Krapu, L.G. Talent, T.J. Dwyer
Use of prairie pothole habitat by breeding mallards
Abstract has not been submitted
Authors
T.J. Dwyer, G.L. Krapu, D.M. Janke