Douglas Johnson (Former Employee)
Science and Products
Filter Total Items: 318
The role of heterogeneity in animal population dynamics The role of heterogeneity in animal population dynamics
No abstract available.
Authors
Douglas H. Johnson, K.P. Burnham, J.D. Nichols
An evaluation of condition indices for birds An evaluation of condition indices for birds
A Lipid Index, the ratio of fat to fat-free dry weight, is proposed as a measure of fat stores in birds. The estimation of the index from field measurements of live birds is illustrated with data on the sandhill crane (Grus canadensis) and greater white-fronted goose (Anser albifrons). Of the various methods of assessing fat stores, lipid extraction is the most accurate but also the most...
Authors
Douglas H. Johnson, Gary L. Krapu, Kenneth J. Reinecke, Dennis G. Jorde
Evaluation of marked-recapture for estimating striped skunk abundance Evaluation of marked-recapture for estimating striped skunk abundance
The mark-recapture method for estimating striped skunk (Mephitis mephitis) abundance was evaluated by systematically livetrapping a radio-equipped population on a 31.4-km2 study area in North Dakota during late April of 1977 and 1978. The study population was 10 females and 13 males in 1977 and 20 females and 8 males in 1978. Skunks were almost exclusively nocturnal. Males traveled...
Authors
Raymond J. Greenwood, Alan B. Sargeant, Douglas H. Johnson
Quick estimates of success rates of duck nests Quick estimates of success rates of duck nests
Abstract has not been submitted
Authors
Douglas H. Johnson, A.T. Klett
The need for accuracy in modelling: An example The need for accuracy in modelling: An example
The need for accurate information in modelling depends on the objectives of the effort, but trustworthy data are essential for a model intended for use in the management of natural resources. This point is illustrated by referring to a recently published model of canvasback ducks. We demonstrate that several key assumptions are not supported by biological evidence, and that inferences...
Authors
Douglas H. Johnson, Michael J. Conroy, James D. Nichols
The need for accuracy in modelling: An example The need for accuracy in modelling: An example
The need for accurate information in modelling depends on the objectives of the effort. but trustworthy data are essential for a model intended for use in the management of natural resources. This point is illustrated by referring to a recently published model of canvasback ducks. We demonstrate that several key assumptions are not supported by biological evidence, and that inferences...
Authors
Douglas H. Johnson, M.J. Conroy, J.D. Nichols
Habitat use by migrant sandhill cranes in Nebraska Habitat use by migrant sandhill cranes in Nebraska
The principal spring staging areas of the midcontinent population of sandhill cranes (Grus canadensis) are along the Platte and North Platte rivers in south-central Nebraska. Most of these lands are privately owned and managed for corn and cattle production. Diurnal habitat use by radio-tagged cranes was primarily in cropland (55%), native grassland (28%), and tame hayland (15%). Ninety...
Authors
Gary L. Krapu, D.E. Facey, E.K. Fritzell, Douglas H. Johnson
Forty-seventh breeding bird census - Kentucky blue grass prairie and Mixed prairie I-V, and VIII Forty-seventh breeding bird census - Kentucky blue grass prairie and Mixed prairie I-V, and VIII
Abstract has not been submitted
Authors
C. A. Faanes, Douglas H. Johnson
[Book review] The youngest science: notes of a medicine-watcher, by Lewis Thomas [Book review] The youngest science: notes of a medicine-watcher, by Lewis Thomas
Review of: The youngest science: notes of a medicine-watcher. Alfred P. Sloan Foundation Series. Lewis Thomas. Penguin Books, 1995. Pennsylvania State University. 270 pp. ISBN: 0140243275, 9780140243277.
Authors
Douglas H. Johnson
Effects of weather on breeding ducks in North Dakota Effects of weather on breeding ducks in North Dakota
The present report quantifies relations between weather and several aspects of the breeding biology of four duck species: mallard (Anas platyrhynchos), gadwall (A. strepera), blue-winged teal (A. discors), and redhead (Aythya americana). Data were obtained from two locations in North Dakota,--the J. Clark Salyer National Wildlife Refuge, intermittently during 1936-68, and the Northern...
Authors
M.C. Hammond, Douglas H. Johnson
Water storage capacity of natural wetland depressions in the Devils Lake basin of North Dakota Water storage capacity of natural wetland depressions in the Devils Lake basin of North Dakota
Photogrammetric mapping techniques were used to derive the water storage capacities of natural wetland depressions other than lakes in the Devils Lake Basin of North Dakota. Results from sample quarter-section areas were expanded to the entire basin. Depressions in the Devils Lake Basin have a maximum storage capacity of nearly 811,000 cubic dekameters (657,000 acre-feet). The...
Authors
A.P. Ludden, D.L. Frink, Douglas H. Johnson
[Book review] Animal population dynamics by R. Moss, A. Watson and J. Ollason [Book review] Animal population dynamics by R. Moss, A. Watson and J. Ollason
No abstract available.
Authors
Douglas H. Johnson, J.W. Grier
Science and Products
Filter Total Items: 318
The role of heterogeneity in animal population dynamics The role of heterogeneity in animal population dynamics
No abstract available.
Authors
Douglas H. Johnson, K.P. Burnham, J.D. Nichols
An evaluation of condition indices for birds An evaluation of condition indices for birds
A Lipid Index, the ratio of fat to fat-free dry weight, is proposed as a measure of fat stores in birds. The estimation of the index from field measurements of live birds is illustrated with data on the sandhill crane (Grus canadensis) and greater white-fronted goose (Anser albifrons). Of the various methods of assessing fat stores, lipid extraction is the most accurate but also the most...
Authors
Douglas H. Johnson, Gary L. Krapu, Kenneth J. Reinecke, Dennis G. Jorde
Evaluation of marked-recapture for estimating striped skunk abundance Evaluation of marked-recapture for estimating striped skunk abundance
The mark-recapture method for estimating striped skunk (Mephitis mephitis) abundance was evaluated by systematically livetrapping a radio-equipped population on a 31.4-km2 study area in North Dakota during late April of 1977 and 1978. The study population was 10 females and 13 males in 1977 and 20 females and 8 males in 1978. Skunks were almost exclusively nocturnal. Males traveled...
Authors
Raymond J. Greenwood, Alan B. Sargeant, Douglas H. Johnson
Quick estimates of success rates of duck nests Quick estimates of success rates of duck nests
Abstract has not been submitted
Authors
Douglas H. Johnson, A.T. Klett
The need for accuracy in modelling: An example The need for accuracy in modelling: An example
The need for accurate information in modelling depends on the objectives of the effort, but trustworthy data are essential for a model intended for use in the management of natural resources. This point is illustrated by referring to a recently published model of canvasback ducks. We demonstrate that several key assumptions are not supported by biological evidence, and that inferences...
Authors
Douglas H. Johnson, Michael J. Conroy, James D. Nichols
The need for accuracy in modelling: An example The need for accuracy in modelling: An example
The need for accurate information in modelling depends on the objectives of the effort. but trustworthy data are essential for a model intended for use in the management of natural resources. This point is illustrated by referring to a recently published model of canvasback ducks. We demonstrate that several key assumptions are not supported by biological evidence, and that inferences...
Authors
Douglas H. Johnson, M.J. Conroy, J.D. Nichols
Habitat use by migrant sandhill cranes in Nebraska Habitat use by migrant sandhill cranes in Nebraska
The principal spring staging areas of the midcontinent population of sandhill cranes (Grus canadensis) are along the Platte and North Platte rivers in south-central Nebraska. Most of these lands are privately owned and managed for corn and cattle production. Diurnal habitat use by radio-tagged cranes was primarily in cropland (55%), native grassland (28%), and tame hayland (15%). Ninety...
Authors
Gary L. Krapu, D.E. Facey, E.K. Fritzell, Douglas H. Johnson
Forty-seventh breeding bird census - Kentucky blue grass prairie and Mixed prairie I-V, and VIII Forty-seventh breeding bird census - Kentucky blue grass prairie and Mixed prairie I-V, and VIII
Abstract has not been submitted
Authors
C. A. Faanes, Douglas H. Johnson
[Book review] The youngest science: notes of a medicine-watcher, by Lewis Thomas [Book review] The youngest science: notes of a medicine-watcher, by Lewis Thomas
Review of: The youngest science: notes of a medicine-watcher. Alfred P. Sloan Foundation Series. Lewis Thomas. Penguin Books, 1995. Pennsylvania State University. 270 pp. ISBN: 0140243275, 9780140243277.
Authors
Douglas H. Johnson
Effects of weather on breeding ducks in North Dakota Effects of weather on breeding ducks in North Dakota
The present report quantifies relations between weather and several aspects of the breeding biology of four duck species: mallard (Anas platyrhynchos), gadwall (A. strepera), blue-winged teal (A. discors), and redhead (Aythya americana). Data were obtained from two locations in North Dakota,--the J. Clark Salyer National Wildlife Refuge, intermittently during 1936-68, and the Northern...
Authors
M.C. Hammond, Douglas H. Johnson
Water storage capacity of natural wetland depressions in the Devils Lake basin of North Dakota Water storage capacity of natural wetland depressions in the Devils Lake basin of North Dakota
Photogrammetric mapping techniques were used to derive the water storage capacities of natural wetland depressions other than lakes in the Devils Lake Basin of North Dakota. Results from sample quarter-section areas were expanded to the entire basin. Depressions in the Devils Lake Basin have a maximum storage capacity of nearly 811,000 cubic dekameters (657,000 acre-feet). The...
Authors
A.P. Ludden, D.L. Frink, Douglas H. Johnson
[Book review] Animal population dynamics by R. Moss, A. Watson and J. Ollason [Book review] Animal population dynamics by R. Moss, A. Watson and J. Ollason
No abstract available.
Authors
Douglas H. Johnson, J.W. Grier