Douglas Johnson (Former Employee)
Science and Products
Filter Total Items: 318
Effects of a summer storm on bird populations Effects of a summer storm on bird populations
Abstract has not been submitted
Authors
Douglas H. Johnson
Modeling sandhill crane population dynamics Modeling sandhill crane population dynamics
No abstract available.
Authors
Douglas H. Johnson
Estimating nest success: The Mayfield method and an alternative Estimating nest success: The Mayfield method and an alternative
Mayfield's method for calculating the success of a group of nests is examined in detail. The standard error of his estimator is developed. Mayfield's assumption that destroyed nests are at risk until the midpoint of the interval between visits leads to bias if nests are visited infrequently. A remedy is suggested, the Mayfield-40% method. I also present a competing model, which...
Authors
Douglas H. Johnson
Interpreting the results of nesting studies Interpreting the results of nesting studies
Nesting studies are used to assess the production of birds and to evaluate nesting habitats. Most such studies involve finding nests in a given area and subsequently determining the proportion that hatched. Unfortunately, the results are often biased by unrecognized differences in the probabilities of finding successful and unsuccessful nests. The observed hatch rates of 1,900 nests of...
Authors
H.W. Miller, Douglas H. Johnson
Breeding bird populations of selected grasslands in east central North Dakota -- 1977 - Kentucky blue grass prairie and mixed prairie I-V, VIII Breeding bird populations of selected grasslands in east central North Dakota -- 1977 - Kentucky blue grass prairie and mixed prairie I-V, VIII
Abstract has not been submitted
Authors
Douglas H. Johnson
Some Bayesian statistical techniques useful in estimating frequency and density Some Bayesian statistical techniques useful in estimating frequency and density
This paper presents some elementary applications of Bayesian statistics to problems faced by wildlife biologists. Bayesian confidence limits for frequency of occurrence are shown to be generally superior to classical confidence limits. Population density can be estimated from frequency data if the species is sparsely distributed relative to the size of the sample plot. For other...
Authors
Douglas H. Johnson
Science and Products
Filter Total Items: 318
Effects of a summer storm on bird populations Effects of a summer storm on bird populations
Abstract has not been submitted
Authors
Douglas H. Johnson
Modeling sandhill crane population dynamics Modeling sandhill crane population dynamics
No abstract available.
Authors
Douglas H. Johnson
Estimating nest success: The Mayfield method and an alternative Estimating nest success: The Mayfield method and an alternative
Mayfield's method for calculating the success of a group of nests is examined in detail. The standard error of his estimator is developed. Mayfield's assumption that destroyed nests are at risk until the midpoint of the interval between visits leads to bias if nests are visited infrequently. A remedy is suggested, the Mayfield-40% method. I also present a competing model, which...
Authors
Douglas H. Johnson
Interpreting the results of nesting studies Interpreting the results of nesting studies
Nesting studies are used to assess the production of birds and to evaluate nesting habitats. Most such studies involve finding nests in a given area and subsequently determining the proportion that hatched. Unfortunately, the results are often biased by unrecognized differences in the probabilities of finding successful and unsuccessful nests. The observed hatch rates of 1,900 nests of...
Authors
H.W. Miller, Douglas H. Johnson
Breeding bird populations of selected grasslands in east central North Dakota -- 1977 - Kentucky blue grass prairie and mixed prairie I-V, VIII Breeding bird populations of selected grasslands in east central North Dakota -- 1977 - Kentucky blue grass prairie and mixed prairie I-V, VIII
Abstract has not been submitted
Authors
Douglas H. Johnson
Some Bayesian statistical techniques useful in estimating frequency and density Some Bayesian statistical techniques useful in estimating frequency and density
This paper presents some elementary applications of Bayesian statistics to problems faced by wildlife biologists. Bayesian confidence limits for frequency of occurrence are shown to be generally superior to classical confidence limits. Population density can be estimated from frequency data if the species is sparsely distributed relative to the size of the sample plot. For other...
Authors
Douglas H. Johnson