IBG Spotlight: Cape May Warbler

Cape May Warbler – digital art from photo by Greg Miller

What is IBG? It’s the Impatient Birder’s Guide. It’s my own creation from eBird data at eBird.org. The latest iteration is from data collected from 2006-2016 as of September, 2016. I have data from the 299 most eBirded counties in the United States representing all 50 States. Nearly half of all the checklists for the U.S. come from these 299 counties.

Ever want to see a certain species but didn’t know where to look? Yes, you checked the range maps for your target species. But that doesn’t tell you where the best place to go. Often the bird ranges cover very large areas. Maybe you even used eBird and looked at the little purple blocks to find areas of highest concentration. Here is a Species Map for Cape May Warbler from eBird. But you may have found quite a few blocks with the same color and intensity. Which block is best?

Ah. That’s where IBG can help. It can give you a list of the top 10 counties and weeks of the year in which a birder will have the very best probability of adding this species to their checklists. In eBird there are 4 weeks for every month (first three weeks are each 7 days and the last week of the month is the remaining days of the month). So eBird has 48 months in a year (4 weeks per month x 12 months). Each of the 299 counties has 48 weeks of data. This means that to find the best location (county) and week of the year for nearly 1,000 species, one would have to evaluate all 14,352 possibilities for each and every species. And that is what IBG represents.

A Top 10 Listing for Cape May Warbler tells you which county to visit and what week of the year is best for the best 10 places and times out of all 14,352 possibilities.

Ready? Let’s get to the point. Where and when can I find today’s target species, the Cape May Warbler? Here are the 10 best possibilities in the United States:

10. Lucas County, in Northwest Ohio from September 15-21 (see Lucas County overview in eBird)

9. Monroe County, in Southern Florida from April 15-21 (see Monroe County overview in eBird)

8. Cobb County, in Northern Georgia from May 1-7 (see Cobb County overview in eBird)

7. Lucas County, in Northwest Ohio from May 15-21 (see Lucas County overview in eBird)

6. Monroe County, in Southern Florida from May 1-7 (see Monroe County overview in eBird)

5. Marion County, Indianapolis area in Indiana from September 15-21 (see Marion County overview in eBird)

4. Clarke County, in East Central Georgia from April 22-30 (see Clarke County overview in eBird)

3. Monroe County, in Southern Florida from April 22-30 (see Monroe County overview in eBird)

2. Cobb County, in Northern Georgia from April 22-30 (see Cobb County overview in eBird)

1. Lucas County, in Northwest Ohio from May 8-14 (see Lucas County overview in eBird)