Results 261 to 270 of about 4,209,032 (298)

A Robust Line Transect Method

Biometrics, 1992
SUMMARY Standard line transect estimation is not robust to departures from the assumptions that animals do not move in response to the observer before detection and that all animals on or near the trackline are detected. We propose field methodology and analysis methods for which estimates are robust to the first assumption and do not require the ...
Stephen T. Buckland, Benjamin J. Turnock
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Measurement Errors in Line Transect Surveys

Biometrics, 1998
Summary: An important assumption used in the analysis of line transect data for animal abundance estimation is that the perpendicular sighting distances of detected animals to transect lines are measured accurately. However, in many line transect surveys, the sighting distances are likely to be subject to measurement errors.
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Line Transect Sampling from a Curving Path

Biometrics, 2001
Cutting straight line transects through dense forest is time consuming and expensive when large areas need to be surveyed for rare or highly clustered species. We argue that existing paths or game trails may be suitable as transects for line transect sampling even though they will not, in general, run straight.
L, Hiby, M B, Krishna
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Kernel Methods in Line and Point Transect Sampling

Biometrics, 1998
Summary: We consider kernel estimation of population density based on size and distance data in line and point transect sampling. Asymptotic normality of the estimators is established in each setting, with very weak assumptions imposed on the random sample size.
Mack, Y. P., Quang, Pham X.
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Spatial Methods for Line Transect Surveys

Biometrics, 1998
Summary: Line transect surveys have traditionally been used only to estimate the mean intensity of an underlying spatial point process. We propose a test for complete spatial randomness and a method of estimating the clustering parameters in a simplified Neyman-Scott Poisson model, using observations collected in a line transect survey with a Gaussian ...
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Mark-Recapture Models for Line Transect Surveys

Biometrics, 1998
Summary: One of the key assumptions of conventional line transect (LT) theory is that all animals in the observer's path are detected. When this assumption fails, simultaneous survey by two independent observers can be used to estimate detection probabilities and abundance.
Borchers, David L., Zucchini, Walter, Fewster, Rachel M.   +2 more
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Parametric Models for Line Transect Surveys

Biometrika, 1979
SUMMARY With data from line transect surveys, the pattern of distances at which animals are detected provides the information for estimating the area which the observer effectively surveys. This paper suggests a parametric structure for the problem wherein this area is characterized by an effective half-width parameter which appears as a scale ...
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Radial-Distance Models for the Line-Transect Method

Biometrics, 1983
Line-transect estimation of wildlife populations can be based on either right-angle distances or radial distances. Estimation based on radial distances requires more restrictive assumptions about the mechanism by which observations are generated. We examine this mechanism and show that the mean sighting angle may frequently be larger than predicted by ...
Hayes, R. J., Buckland, S. T.
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Perpendicular Distance Models for Line Transect Sampling

Biometrics, 1985
Perpendicular distance line transect models are examined to assess whether any single model can provide a general procedure for analysing line transect data. Of the two-parameter models considered, the hazard-rate model appears promising, whereas the exponential power series and exponential quadratic models do not.
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Some Mathematical Models for Line Transect Sampling

Biometrical Journal, 1985
AbstractANDERSON and POSPAHALA (1970) investigated the estimation of wildlife population size using the belt or line transect sampling method and devised a correction for bias, thus leading to an estimator with interesting characteristics. This work was given a uniform mathematical framework in BURNHAM and ANDERSON (1976).
Anderson, D. R., Burnham, K. P., Crain, B. R.   +2 more
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