The effect of time period on point count methodology for monitoring breeding birds

Abstract

The traditional time period to survey breeding birds in low elevation forests of western Montana is from the middle of May through early July. There are some bird species, however, that begin their breeding cycle before these surveys begin and, therefore, may not be as vocal or active during the traditional survey period. To study the impact of survey timing on our understanding of the breeding bird community, we undertook a two year study of breeding birds in old-growth ponderosa pine (Pinus ponderosa) habitat in western Montana in 1996 and 1997. We chose eight sites and sampled each site with a transect of 5 points, 200 meters apart using standard bird point count methodology (Ralph and others 1995). Observers visited each site a total of ten times each year from mid- to late April until the end of June and recorded the number of each species seen or heard at each point on the transect. Over the two years, a total of 52 species and 6,730 individuals were detected within 100 meters of the counting points. The highest numbers of individuals and species were generally detected during the traditional survey period, confirming this time period as the best for surveying breeding birds in this habitat in western Montana. However, some resident and short distance migratory species were detected more frequently during the first five visits, indicating that they may be underrepresented in point count surveys beginning in mid-May. We also demonstrate that the use of habitat by flocking species may not be represented accurately in a single year’s survey.

Parent Publication

• The Bitterroot Ecosystem Management Research Project: What we have learned

Citation

Hejl, Sallie J.; Thompson, Thomas G. 2000. The effect of time period on point count methodology for monitoring breeding birds. In: Smith, Helen Y., ed. 2000. The Bitterroot Ecosystem Management Research Project: What we have learned: symposium proceedings; 1999 May 18-20; Missoula, MT. Proc. RMRS-P-17. Ogden, UT: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. p. 48-52