Double Kernel Method Using Line Transect Sampling

Some Improvements in Kernel Estimation Using Line Transect Sampling

Adaptive line transect sampling.

Adaptive line transect sampling offers the potential of improved population density estimation efficiency over conventional line transect sampling when populations are spatially clustered. In adaptive sampling, survey effort is increased when areas of high animal density are located, thereby increasing the number of observations. Its disadvantage is that the survey effort required is not known ...

Zigzag Survey Designs in Line Transect Sampling

Zigzag survey lines are frequently used in shipboard and aerial line transect surveys of animal populations. Analysis proceeds assuming that coverage probability through the survey region is uniform. We show that the two types of zigzag design that are in wide use do not generally have this property, and explore the degree of bias in abundance estimates that can be anticipated. We construct a z...

Line transect sampling from a curving path.

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. Formulas and software currently used to estimate local density using perpendicular d...

Spatial Models for Line Transect Sampling

This article develops methods for fitting spatial models to line transect data. These allow animal density to be related to topographical, environmental, habitat, and other spatial variables, helping wildlife managers to identify the factors that affect abundance. They also enable estimation of abundance for any subarea of interest within the surveyed region, and potentially yield estimates of ...