Douglas Johnson (Former Employee)
Science and Products
Filter Total Items: 318
Determinants of breeding distributions of ducks Determinants of breeding distributions of ducks
The settling of breeding habitat by migratory waterfowl is a topic of both theoretical and practical interest. We use the results of surveys conducted annually during 1955-81 in major breeding areas to examine the factors that affect the distributions of 10 common North American duck species. Three patterns of settling are described: homing, opportunistic, and flexible. Homing is...
Authors
Douglas H. Johnson, J.W. Grier
[Book Review] Building Models for Conservation and Wildlife Management, by A. M. Starfield and A. L. Bleloch [Book Review] Building Models for Conservation and Wildlife Management, by A. M. Starfield and A. L. Bleloch
Review of: Building Models for Conservation and Wildlife Management. By Anthony Starfield and A. L. Bleloch. New York: Macmillan; London: Collier Macmillan, 1986. ISBN: 002948040X. xi, 253 p.: ill.; 25 cm.
Authors
Douglas H. Johnson
Some considerations in modeling the mallard life cycle Some considerations in modeling the mallard life cycle
We outline a population model proposed to accommodate the full life cycle of the mallard (Anas platyrhynchos}. Events during the breeding season are better understood than events at other times of the year, but recent findings suggest the importance of phenomena away from the breeding grounds. Several processes are discussed relative to mallard population dynamics. Compensatory mortality...
Authors
Douglas H. Johnson, J.D. Nichols, M.J. Conroy, L.M. Cowardin
Workshop summary: Hunting vulnerability and mortality Workshop summary: Hunting vulnerability and mortality
No abstract available.
Authors
Frank Montalbano, Douglas H. Johnson, M. R. Miller, D. H. Rusch
Some considerations in modeling the mallard life cycle Some considerations in modeling the mallard life cycle
We outline a population model proposed to accommodate the full life cycle of the mallard (Anas platyrhynchos). Events during the breeding season are better understood than events at other times of the year, but recent findings suggest the importance of phenomena away from the breeding grounds. Several processes are discussed relative to mallard population dynamics. Compensatory mortality...
Authors
Douglas H. Johnson, J.D. Nichols, M.J. Conroy, L.M. Cowardin
Applications of a simulation model to decisions in mallard management Applications of a simulation model to decisions in mallard management
A system comprising simulation models and data bases for habitat availability and nest success rates was used to predict results from a mallard (Anas platyrhynchos) management plan and to compare six management methods with a control. Individual treatments in the applications included land purchase for waterfowl production, wetland easement purchase, lease of uplands for waterfowl...
Authors
L.M. Cowardin, Douglas H. Johnson, T.L. Shaffer, D. W. Sparling
Science and Products
Filter Total Items: 318
Determinants of breeding distributions of ducks Determinants of breeding distributions of ducks
The settling of breeding habitat by migratory waterfowl is a topic of both theoretical and practical interest. We use the results of surveys conducted annually during 1955-81 in major breeding areas to examine the factors that affect the distributions of 10 common North American duck species. Three patterns of settling are described: homing, opportunistic, and flexible. Homing is...
Authors
Douglas H. Johnson, J.W. Grier
[Book Review] Building Models for Conservation and Wildlife Management, by A. M. Starfield and A. L. Bleloch [Book Review] Building Models for Conservation and Wildlife Management, by A. M. Starfield and A. L. Bleloch
Review of: Building Models for Conservation and Wildlife Management. By Anthony Starfield and A. L. Bleloch. New York: Macmillan; London: Collier Macmillan, 1986. ISBN: 002948040X. xi, 253 p.: ill.; 25 cm.
Authors
Douglas H. Johnson
Some considerations in modeling the mallard life cycle Some considerations in modeling the mallard life cycle
We outline a population model proposed to accommodate the full life cycle of the mallard (Anas platyrhynchos}. Events during the breeding season are better understood than events at other times of the year, but recent findings suggest the importance of phenomena away from the breeding grounds. Several processes are discussed relative to mallard population dynamics. Compensatory mortality...
Authors
Douglas H. Johnson, J.D. Nichols, M.J. Conroy, L.M. Cowardin
Workshop summary: Hunting vulnerability and mortality Workshop summary: Hunting vulnerability and mortality
No abstract available.
Authors
Frank Montalbano, Douglas H. Johnson, M. R. Miller, D. H. Rusch
Some considerations in modeling the mallard life cycle Some considerations in modeling the mallard life cycle
We outline a population model proposed to accommodate the full life cycle of the mallard (Anas platyrhynchos). Events during the breeding season are better understood than events at other times of the year, but recent findings suggest the importance of phenomena away from the breeding grounds. Several processes are discussed relative to mallard population dynamics. Compensatory mortality...
Authors
Douglas H. Johnson, J.D. Nichols, M.J. Conroy, L.M. Cowardin
Applications of a simulation model to decisions in mallard management Applications of a simulation model to decisions in mallard management
A system comprising simulation models and data bases for habitat availability and nest success rates was used to predict results from a mallard (Anas platyrhynchos) management plan and to compare six management methods with a control. Individual treatments in the applications included land purchase for waterfowl production, wetland easement purchase, lease of uplands for waterfowl...
Authors
L.M. Cowardin, Douglas H. Johnson, T.L. Shaffer, D. W. Sparling