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| | NPWRC :: Point Counts of Birds: What Are We Estimating? |
 | | Abstract: Point counts of birds are made for many reasons, including estimating local densities, determining population trends, assessing habitat preferences, and exploiting the activities of recreational birdwatchers. |
 | | A point count, or circular-plot survey, involves a series of points or stations at which birds are counted. |
 | | But as the count period is extended, the number of birds present sometime during the count period increases, because of territories that partially overlap the study area (Granholm 1983, Scott and Ramsey 1981). |
| www.npwrc.usgs.gov /resource/birds/ptcounts (3882 words) |
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