| Abstract: | Acquiring an accurate picture of the changes in bird populations often involves a tradeoff between the time and effort required to complete the surveys and the number of years spent surveying the bird populations. An alternative approach to long-term monitoring efforts is to collect current data and contrast those with data collected earlier in a similar fashion on the same study site(s). To evaluate changes in bird populations, we repeated two extensive surveys, one in North Dakota (1967 vs. 1992-1993) and the other in the Platte River Valley of Nebraska (1979-1980 vs. 2001), where large areas of native vegetation had been converted to agriculture. We use these examples and others from the literature to illustrate the advantages and disadvantages of using historical data as a frame of reference for population changes. |
| Genre: | Federal Government Series |
| ProdID: | 2000143 |
| Citation Author: | Igl, L. D.; Johnson, D. H. |
| Citation Contributing Office: | Northern Prairie Wildlife Research Center |
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| Citation End Page: | 830 |
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| Citation Language: | English |
| Citation Larger Work Title: | Bird Conservation Implementation and Integration in the Americas: Proceedings of the Third International Partners in Flight Conference |
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| Citation Number Of Pages: | 14 |
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| Citation Phsyical Description: | p. 817-830 |
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| Citation Publisher: | U.S. Forest Service |
| Citation Series: | General Technical Report |
| Citation Series Code: | General Technical Re |
| Citation Series Number: | GTR-PSW-191 |
| Citation Search Results Text: | A retrospective perspective: evaluating population changes by repeating historic bird surveys; 2005; Federal Government Series; General Technical Re; GTR-PSW-191; Bird Conservation Implementation and Integration in the Americas: Proceedings of the Third International Partners in Flight Conference; Igl, L. D.; Johnson, D. H. |
| Citation Start Page: | 817 |
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| Citation Year: | 2005 |
| Type: | citation/reference |
| Text: | A retrospective perspective: evaluating population changes by repeating historic bird surveys; 2005; Federal Government Series; General Technical Re; GTR-PSW-191; Bird Conservation Implementation and Integration in the Americas: Proceedings of the Third International Partners in Flight Conference; Igl, L. D.; Johnson, D. H. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| URL (DOCUMENT): | http://library.npwrc.cr.usgs.gov/diglib/npwrc/npwrc1473.pdf |
| Date Other: | Sat, 1 Jan 2005 01:00 -0600 |
| Publisher: | U.S. Forest Service |
