Christmas Bird Count history report system

Show the complete history of a single count circle, two or more overlapping circles, an entire state, or even the entire database.

In addition to a conventional XHTML tabular display, this system will also generate a report in PDF or spreadsheet format.

Because many of the names in the database are obsolete, in many cases a circle report will show the data for what is clearly the same kind of bird scattered across two or more rows of the table. For example, what was called Holboell's Grebe became Red-necked Grebe in about 1950. There must be a mechanism for collapsing these rows into one that more clearly shows the population trend.

The user can select or exclude any number of years or ranges of years.