This point count-based protocol appears as a summary chapter in a 1995 US Forest Service technical report. The chapter outlines agreed-upon standards and their applications to point count methodology that resulted from a 1991 workshop to evaluate point counts and to work toward the standardization of methods to monitor bird populations by census. The protocol allows for collection of landbird data in a variety of habitat types for the purposes of conducting inventories, estimating relative abundance, estimating densities, estimating population trends, or determining associations between birds and their habitats. It organizes data collection into temporal and spatial bins and provides guidance on survey point placement, replication and timing of surveys (in relation to time of day, season, and weather). The protocol has been widely adopted by researchers and land managers over the many years since its publication in 1995, and has served to provide a level of standardization in bird point count data collection that was previously missing.
One of the protocol’s greatest strengths is that of providing guidance for implementation of bird surveys based on the stated objectives of the end user. This allows for great flexibility and adaptability of the protocol to a variety of situations, while still maintaining standardization in the manner in which data are collected. Collection of bird abundance data in temporal bins of 3, 2 and 5 minutes allows for comparison with data collected under other protocols (ex. North American Breeding Bird Survey).
In recent years, greater emphasis has been placed on applying detectability-based correction factors to bird abundances to more accurately estimate the number of birds at a site. Detection probabilities can be estimated through the Ralph et al. (1995) protocol through repeated measurements at a point, or by recording distance to individuals through a variable circular plot method. Because the latter technique requires a relatively precise estimation of distances, it is best applied using highly trained observers and only in bird communities with relatively few and conspicuous species (Verner 1985 in Ralph et al. 1995). Enhancement of the protocol to include a greater number of distance bins can also allow calculation of detection probabilities (Rosenstock et al. 2002).
Examples of use
The protocol has enjoyed nearly universal use in landbird surveys and monitoring since its publication. Note that Hamel and others (1996) developed a similar protocol (see below) which was targeted specifically for use in the Mississippi Alluvial Valley and the broader southeastern US region and which has been adopted by the USDA Forest Service Southeast Region.
For more informationLiterature Cited
Ralph, C.J., S. Droege and J.R. Sauer. 1995. Managing and Monitoring Birds Using Point Counts: Standards and Applications. Pages 161-168 in C. J. Ralph, J. R. Sauer, and S. Droege, Eds. Monitoring Bird Populations by Point Counts, USDA Forest Service, Pacific Southwest Research Station, General Technical Report PSW-GTR-149.
Rosenstock, S.S., D.R. Anderson, K.M. Giesen, T. Leukering, and M.F. Carter. 2002. Landbird Counting Techniques: Current Practices and an Alternative. Auk 119(1):46-53.
Verner, J. 1985. Assessment of counting techniques. Current Ornithology 2: 247-302.
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