In a previous post I mentioned that I mainly bird only my local area. So how does one define one’s local area?
My definition is based on the fact that I work Monday through Friday and have a family. Not that unusual. But it puts limits on my birding time. So I define my birding area as the area closest to my residence that I can see the most species with the least amount of driving.
Think of it as concentric circles around your house. How many species can you see in a circle 100 yards around your house? One-mile? 10 miles? etc. Looking at a status and distribution chart (like eBird) and knowing the local habitat, one can make some educated guesses. If I would bird within a mile or two of my house, i.e. walking distance, I could probably see 40 to 50 species. Increase the circle to 10 miles which includes a state fish and wildlife area and the total jumps to approximately 190 species.
So adding 10 to 20 miles to my circle wouldn’t offer many benefits. But I occasionally jump over the “dead zone” from 10 to 30 miles and bird a large lake which expands the list by 15 to 20 species. The next leap would be to 75 miles (Goose Pond) and maybe get me close to 230. From there I would have to jump the circle to 175 miles (Lake Michigan and Southern Indiana) to add another 10 species. You get the idea. There are layers of “dead zones”, like from 10 to 30 miles and 35 to 75, that if I bird would not greatly increase my chances of seeing additional species.
So I don’t waste my limited birding time driving any farther than 10 to 12 miles from my house since I will probably end up seeing approximately 95% of the birds that normally occur in my state away from Lake Michigan. All I have to do is throw in a couple of trips and I’ll see most of the birds that do regularly occur in the state.
To illustrate my point I’ll use my residence in Illinois since I haven’t completed a full year in Indiana. The usual count in my 15 mile circle was 220 species per year. Driving 40 miles to a large marshy lake added another 10 per year. Driving a few times in the fall the 75 minutes to a larger lake would add another five or six species, mainly loons, grebes, and scooters. And a couple of times per year I’d travel to Southern Illinois and see an additional 5 to 10 species. So I would usually see 240 to 250 species per year in my home state. A number I find personally satisfying without driving great distances.
Have you downloaded your eBird data?