DISTANCE- software program that provides an analysis of distance sampling data to estimate density and abundance of a population

Distance is a software program that provides an analysis of distance sampling data to estimate density and abundance of a population. Distance evolved from program TRANSECT- a DOS-based program that was written to analyze line transect data (Burnham, K.P., Anderson, D.R., and Laake, J.L. 1980. Estimation of density from line transect sampling of biological populations. Wildlife Monograph No. 72.). However, Distance is quite different from its predecessor as a result of changes in analysis methods and expanded capabilities. Distance versions 1.0 - 2.2 were DOS-based applications that were programmed using a relatively simple command language. Version 3.0 was a windows console application, but retained the command language structure. All of these versions were principally programmed by Jeff Laake of the National Marine Mammal Laboratory, US Fisheries Service. In 1997, Steve Buckland and David Borchers, from the University of St Andrews, obtained funding from two British research councils to proceed with an ambitious three-year project to develop new distance sampling software. The new software, which became known as Distance 4, was designed to be fully windows-based, and be capable of incorporating new features such as geographic survey design, multiple covariate detection function models, spatial estimation of abundance, and dual observer mark-recapture line transect methods. A Distance 4 project development team was assembled, coordinated by Len Thomas. In autumn1997, we decided to produce an intermediate version of Distance: fully windows based, but with the same analysis capabilities as the current version 3.0. This new program, Distance 3.5, took one full year to develop, and was released in November 1998, with various updates through to February 1999. Distance 3.5 has been downloaded by over 2000 users, from over 100 countries. Extension of Distance 3.5 to become Distance 4 began in 1999, and the software was first previewed at training workshops in summer 2000. A beta version has now been released, containing the survey design and multiple covariate enhancements. We are currently working on finalizing this version, and are planning on incorporating the other new features as time and funding permits.