Archive for May, 2011
A Great Farewell
Posted by: | CommentsI knew that yesterday would be my last birding day in Vancouver, so Daniel and I set out at dawn to see what we could see. It turned out to be a great day, with excellent looks at six owls of three species: Barn, Great Horned, and Barred, plus a few migrants here and there.
But nothing could match the first notable bird of the day.
On a tip from David, we headed straight to Burnaby Mountain. Within a couple of minutes of leaving the parking lot, we heard it: the almost inaudibly low-pitched hooting of a male Sooty Grouse. Walking along the clifftop, we knew that we were not only close to the bird–close enough to tell when it moved its head–but perhaps even at something like the same elevation; but long minutes passed as we stared into the dark tree tops.
Just as we were about to resign ourselves to yet another purely aural encounter, a rush of wings announced the arrival of the bird on a bare broken branch just yards away. It looked around a couple of times, then started to boom–five, sometimes six deep, owl-like hoots, softer and louder as the bird directed its voice towards us, then away.
It was obviously a matter of great exertion to make such a sound. The bird leaned slightly forward, puffed out its belly, then its breast, and the tail vibrated with each emanation. The combs were visible, but the neck sacs remained almost entirely covered by feathers the entire time.
After nearly half an hour of watching, I muttered something about not even wishing for a better look. The grouse took my speaking as its cue to fly towards and between us, landing on the green lawn and strolling a couple of feet into–get this–a bed of daffodils, where it plucked at the flowers for a few seconds before something, probably an introduced eastern gray squirrel, flushed it; it flew back across the fence and down the cliff, landing somewhere out of sight.
This was the first Sooty Grouse I’d ever actually seen, and to watch it boom and perch and fly and feed was almost overwhelming–and a wonderful way to say goodbye to Vancouver.
Markedness
Posted by: | CommentsAs birders learn to look closer, we more and more detect birds that somehow don’t fit the categories of the birdy books. Individual variation accounts for some of that, but many of the odd birds we encounter are, or at least seem to be, hybrids and intergrades, the products of matings more enthusiastic than accurate.
Some such hybrids are pretty obvious, like this apparent Mallard x Northern Pintail.
In many cases, though, the putative parent species are so similar to begin with, and their offspring so variable, that distinguishing between a “pure” individual and a hybrid can be a real challenge.
This gull at Clover Point this past weekend, for example, showed the mix of Western and Glaucous-winged Gull characters typical of our local “Puget Sound Gull”: a darkish mantle, blackish wingtips above, faintly marked wingtips below, and an orbital ring mixed yellow and red.
And this goose, hanging out in a Tucson park this winter, could easily have been mistaken for a Ross’s Goose without a closer look at the long bill with a slight “grin patch.”
These are old stories and familiar, but lately I’ve been thinking about when birders look for (and find) hybrids. What it comes down to is markedness, or which potential parent taxon is deemed the default. This varies geographically, of course: in the east, a reddish Northern Flicker will be scrutinized, while over much of the west it’s the apparently yellow-shafted birds that draw special attention.
But I don’t think that markedness is always just about rarity and vagrancy. Even in those areas–and there are more and more of them as time goes on–where, say, Snow and Ross’s Geese are equally expected, it’s only the apparent Ross’s that are inspected for signs of hybridization: how often have you heard anyone cautiously report “an apparently pure Snow Goose,” even in places like southeast Arizona where both white geese are uncommonish? Nobody ever objects that a tentative Snow Goose’s bill is a bit short or the head a bit round or the plumage a bit white.
Even more strikingly, here in Vancouver I notice that birders (by which I mean mostly myself) readily pass over the slightly uncommon Myrtle Warblers, while subjecting the more abundant Audubon’s Warblers to a much more thorough examination. Adult male Audubon’s types with white in the throat or lightly marked wing coverts? Probable hybrids! But I simply tick the Myrtles; even when I linger over a particularly snazzy one (they are really very beautiful), I more often than not wind up moving on without checking it over at all as carefully as I do the yellow-throated birds. But surely there are hybrids that more closely resemble Myrtles than Audubon’s, aren’t there?
The lesson that I’ve drawn from these musings? Start to treat all the birds I see as “marked,” as potentially something different and weird–as worth looking at more closely than I already do. Who knows what I’ll find now?
