I take a walk over my lunch break at work and while I do that, I keep track of the butterflies. I have done this over a period of time–I have records going back through the summer of 2003.
Initially I just counted all of the butterflies I saw, but after a couple of years I started doing a survey that more closely resembles a “Pollard Transect.” I timed the survey, and only counted the butterflies within a defined distance of where I passed.
The area I walk is at Camp Dodge in the Cantonment Area. Think of it like a suburban habitat–it is surrounded by closely cropped grasses, few flowers, and a few trees.
This graph shows how 2011 stacks up against the average of the previous eight years:
In general, the rates of butterfly observations were slightly lower for 2011 than average, but not by much. Butterfly numbers built up slower than previous years but the populations were comparable by the end of the year.
Below is a pie chart showing the species composition of the surveys. Keep in mind that this is a heavily modified environment. A more natural environment might be expected to have a more uniform distribution of species.
Butterfly surveys are fun and fairly easy to do. I recommend them as a way to enhance the butterfly watching experience.
They should start showing up in another 10 weeks or so.