Wednesday, July 6, 2011
Two, Four, Six, Eight, Try To Estimate!
“How many [Ruby-crowned] kinglets?” I asked, notebook in hand, pen poised to record the official tally.
“At least a couple dozen…maybe twenty-six?” responded my girlfriend Alison, behind the wheel as we pulled away from Floral Lane, an alleged hotspot that I have thus far found to be positively underwhelming.
“Don’t be ludicrous,” I scolded. “Fourteen.”
“Come on. They were ALL over the place. I saw six in one bush.”
Seeing the validity of both statements, I conceded. “All right, fine. Sixteen.”
Both of us are notoriously strong-willed people. The debate nearly dissolved into blows, but eventually we peacefully agreed that we had, indeed, seen sixteen Ruby-crowned Kinglets on our walk. He who wields the pen holds power.
It’s a time-honored tradition of mine. Go birding, have a good time. Then, afterwards, estimate the numbers of birds you saw and punch them into eBird. How representational are these estimates—often little more than wild guesses—of the true number of birds present? Some situations offer challenges, like…
A cloud of swallows swirling back and forth over a field…thousands upon thousands of gulls blanketing the center dike at Muskegon Wastewater…a chorus of unseen Wrentits trilling from hill cloaked in chaparral…ubiquitous Black Phoebes, one standing guard over seemingly every trash can in the neighborhood.
An even greater challenge faces birders entering eBird checklists from memory: whether a species was even present or not. Did I hear any Song Sparrows on my evening walk around the evening? Well, surely I did—must have just forgotten to write it down on my little pad. How many? Well, I don’t know, but usually there seem to be about three singing males in the neighborhood, so I’ll put down three. Yeah, three, I remember them all now…
I’ve become halfway diligent at jotting down all the species I detect in a pocket notebook that I feel naked without. Recording numbers, however, is another story. Leaving the estimations to the end frequently leads to intense personal frustration (when I bird with myself) or verbal, possibly even physical conflict (when I bird with others). In addition to these negative side effects of estimation, is it even accurate? I decided to test the accuracy of my estimation on a recent evening ramble to Irvine Regional Park by carefully tallying numbers of several species.
The first thing I noticed: Black Phoebes are freaking everywhere. I encountered eleven in less than a mile of walking. On my previous four visits of comparable effort, I estimated three, six, one, and seven birds, respectively. Second observation: Cliff Swallows are impossible to count, screw this. Third observation: Mourning Doves, that’s better. Fly in a straight line, one or two at a time. I can handle this. I ended up with seventeen, compared with forty, twenty-six, eighteen, and thirty-eight on previous visits. Fourth observation: Shoot, eight-thirty, almost my bedtime...better head back.
These two case studies might suggest that my estimation powers are reasonably accurate. I do not, however, flatter myself to be convinced so easily. Oftentimes, when confronted with a species scrawled on my notepad, I am completely at loss as to how many I saw. This challenge is two-pronged. It involves memory, sometimes over hours, and it also requires synthesizing a total of birds seen over a period of time—when out birding, you see those Yellow-rumped Warblers a few at a time, not all at once. Out of curiosity, I googled “estimation games” and blew an enjoyable few minutes testing myself (http://tinyurl.com/3re74py). Embarrassingly, I nearly scored negatively on the “Count 50-99” level, but then I promptly dominated the “Count 20-50” level. It seems that I am forever doomed to be ignorant of my level of estimation skill…
One of my goals for the remainder of the summer is to be more aggressive in keeping track of bird numbers while birding and not saving the estimation for the end. It requires considerable time and diligence, both of which I seem to perpetually lack. But who knows? Perhaps, by the end of the summer, my eBird account will be spewing forth data that are slightly more accurate.