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D.R. Anderson

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A nonparametric, robust density estimation method is explored for the analysis of right-angle distances from a transect line to the objects sighted. The method is based on the FOURIER series expansion of a probability density function over an interval. With only mild assumptions, a general population density estimator of wide applicability is obtained.
Categories: Publication; Types: Citation; Tags: Biometrical Journal
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A general mathematical theory of line transects is developed which supplies a framework for nonparametric density estimation based on either right angle or sighting distances. The probability of observing a point given its right angle distance (y) from the line is generalized to an arbitrary function g(y). Given only that g(0) = 1, it is shown there are nonparametric approaches to density estimation using the observed right angle distances. The model is then generalized to include sighting distances (r). Let f(y I r) be the conditional distribution of right angle distance given sighting distance. It is shown that nonparametric estimation based only on sighting distances requires we know the transformation of r given...
Categories: Publication; Types: Citation; Tags: Biometrics
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(1) The life table model is frequently employed in the analysis of ringer samples of young in bird populations. The basic model is biologically unrealistic and of little use in making inferences concerning age-specific survival probabilities. (2) This model rests on a number of restrictive assumptions, the failure of which causes serious biases. Several important assumptions are not met with real data and the estimators of age-specific survival are not robust enough to these failures. (3) Five major problems in the use of the life table method are reviewed. Examples are provided to illustrate several of the problems involved in using this method in making inferences about survival rates and its age-specific nature....
Categories: Publication; Types: Citation; Tags: Journal of Animal Ecology
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Basic information obtained from the July Waterfowl Production Survey is presented in 32 Appendix tables for the period 1955-71. The discussion of the data is minimized because the report is designed primarily to make the data available to waterfowl biologists and other interested individuals. Data presented include: (1) the number of July ponds, (2) the brood index, (3) the average size forClass II and Cia s s !II broods, and (4) the late nesting index. These statistics are presented for each stratum surveyed. A few of the obvious correlations are discussed, although more refined analyses of the data will be presented in the Mallard Study reports. Furthermore, additional supporting information will be available...
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