Friday, June 13, 2008
I think it would be impossible for any person with a heart to walk past this bird without exclaming "Awwwwww... it's so cute!" There is, in fact, a reason for that. The bird is cute. Majorly so. What defines its cuteness? Those wide, black eyes? The tiny size of the bird? Don't ask. It's just cute. Very unscientific, but it's true.
But... what is it? It wouldn't take very long for the average birder to come to the conclusion that it is a flycatcher, more specifically one of those cursed empidonax. Some of the species in this tribe are olive-gray, and several others are gray-olive. The sensible birder would shrug and turn away. The foolish one would actually attempt to identify it, doomed to eternity of staring at wing bars, tertial fringes, emarginated primaries...
Fortunately, it isn't quite that bad. Subtle differences between the various species exist, but it takes the observant birder to find them. Thankfully, almost all of the species have unique calls. Range can also narrow down the options. In southern California, the default empid in the lowlands is the Pacific-slope Flycatcher (incidentally, I find this a very cool name. I always think of a little flycatcher sliding down the hypotenuse of a 30-60-90 triangle into the Pacific Ocean... I need to take it easy on the geometry!) These diminutive balls of fluff are adorable and harmless in our eyes, but in the eyes of small insects they are terrible predators. In the hand, they try to intimidate the bander by snapping their bill loudly. The only result of this action is usually laughter from the bander.
Right - I banded this bird today at Starr Ranch. Its wing was 59 millimeters long; it weighed 9.4 grams; it had a fat score of one. I aged it as a hatch-year - those wing bars aren't just buff; they're pumpkin buff. This feature, along with the overall fuzziness of the bird (especially around the undertail coverts and belly), the brownish wash over the upperparts, and the slightly swollen gape (dubbed the "baby-gape") aged it as a hatch-year. I wondered how long it will live. Will it make it to the end of the day? A year? Five years? Who knows. That's one reason why we're banding them.