Distance sampling survey effort to improve density estimates of northern bobwhite

Sampling of Bobwhite Populations Estimating Sample Sizes for Distance Sampling of Autumn Northern Bobwhite Calling Coveys

Point transect sampling of calling coveys has been advocated for estimating autumn abundance of northern bobwhite (Colinus virginianus; hereafter bobwhite). We conducted power analysis, over a range of expected bobwhite calling covey densities to determine levels of sampling required to obtain density estimates for calling coveys over a wide range of precision. We used distance/detection inform...

Modifying distance methods to improve estimates of historical tree density from General Land Office survey records

ANDERSON, R. C., S. L. JONES, AND R. SWIGART (Department of Biological Sciences-4120, Illinois State University, Normal, IL 61790-4120). Modifying distance methods to improve estimates of historical tree density from General Land Office survey records. J. Torrey Bot. Soc. 133: 449–459. 2006.—Distance sampling methods are widely applied to witness tree data from General Land Office (GLO) survey ...

Adjusting count period strategies to improve the accuracy of forest bird abundance estimates from point transect distance sampling surveys

Although point transect distance sampling methods have become widely used in surveys of forest birds, there has been no attempt to tailor field methods to maximize the accuracy of abundance estimates by minimizing the effects of violations of the method’s critical assumptions, which are: (1) birds at distance 0 m are detected with certainty, (2) birds are detected at their initial location and ...

A Density-Biased Sampling Technique to Improve Cluster Representativeness

Can we improve estimates of juvenile dispersal distance and survival?

Estimates of distributions of natal dispersal distances and juvenile recruitment rates in open populations are strongly influenced by the extent and shape of the areas sampled. Techniques to improve biased dispersal and survival estimates include area-ratio methods based on weighting observations by sampling effort, the extent and shape of the area sampled, and the amount and distribution of pr...