North American Breeding Bird Survey

1966 - 1998 Trend Analysis Form


This part of the Home Page allows you to access a summary list of trends for either a species or a region.

Simply select the sort of summary you want (by species or region), then select the region (or species) of interest.

These results are based on the Route-regression, estimating equations method.

Note: You can also access the annual indices from from the lists- Just click on the links for the regions (or species). I have not yet put in checks for missing data, so some of these will be missing (low sample size results, for example).


Cautions regarding BBS data: 3 December 1999:
1. We live and learn. The database has been extensively edited between 1996 and 1998, but these changes have not been peer-reviewed. Please remember that all results should be viewed with a critical eye.
2. Taxonomic changes have been implemented in data base, but not yet reviewed.
3. Data quality codes were also revised in data base, eliminating ca 10% of data used in earlier analysis.
Need help in figuring out what the numbers mean?

Please enter type of results requested:

Trends for a species Trends for a region

If Species, please select the species name:

If Region, please enter the region of interest:

Do you want stars or exact P values to denote significance?:

P values Stars
Note: if you choose stars: *=P less than 0.20; **=P less than 0.10; ***=P less than 0.05; ****=P less than 0.01. If you choose P values, the exact P value is listed.



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BRD Data Liability Disclaimer

Although these data have been processed successfully on a computer system at the Biological Resource Division, no warranty expressed or implied is made regarding the accuracy or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. This disclaimer applies both to individual use of the data and aggregate use with other data. It is strongly recommended that these data are directly acquired from a Biological Resource Division server, and not indirectly through other sources which may have changed the data in some way. It is also strongly recommended that careful attention be paid to the contents of the metadata file associated with these data. The Biological Resource Division shall not be held liable for improper or incorrect use of the data described and/or contained herein.

So, these data are provided "as is" and without any express or implied warranties, including, without limitation, the implied warranties of merchantability and fitness for a particular purpose. Also, use of trade names or commercial products in this home page is solely for the purpose of providing specific information, and does not imply recommendation or endorsement by the U.S. Government.