Archive for July, 2010
Peña Blanca Monsoon
Posted by: | CommentsToday was scouting day for my Southwest Wings field trip to California Gulch–but Lori and I didn’t make it nearly that far. Early, early we drove south past mountains wrapped in thick monsoon skies, over moraines of rain-driven gravel and cobbles, and around tangles of flotsam left on the roads by last night’s storm.
And then, just a few hundred yards in on Ruby Road, we encountered this.
It may not look like a lot of water, but it was moving fast and hard, and probably carrying more than enough sediment to wash even the squattest of Subarus off the sharp edge of the road and downstream.
I hemmed, I hawed, I chickened out.
After a few minutes of admiring the torrent, we turned around and drove back to Peña Blanca Lake, where the water was flowing just as furious. But the parking lot was still accessible, and a narrow, instable spit of land still protruded into the west end of the lake where the boat ramp once was. We walked out, and walked into a feeding frenzy.
Dragonflies big and small were skimming the waters where they calmed, and they were hunted in turn by a good dozen Cassin’s Kingbirds and half that many Brown-crested Flycatchers, noisy even over the roar of the flowing wash. A couple of Vermilion Flycatchers and a family of Black Phoebes, the kids still sporting their bright brown wingbars and yellow gap flanges, sought smaller prey, while a Northern Beardless-Tyrannulet seemed to spend almost as much time singing as it did picking through the leaves. Summer Tanagers, Yellow Warblers, and Northern Cardinals added color to the scene, and drama was provided by two Black Vultures that took off from their clifftop roost above us. A juvenile Gray Hawk screamed and squawked, but its stunning parent was obviously “weaning” it, flying in with prey in its feet to land close to the still keening, still hungry juvenile, then taking off without sharing whatever unfortunate frog or lizard had crossed its path.
Just as we were thinking about leaving this lively scene, we cast another glance at the two Spotted Sandpipers that had been bobbing on the flotsam–and this time we picked up another movement in the water. It was the pair of Least Grebes that Cliff had discovered last week, and for a good quarter of an hour they plied the muddy waters in front of us, diving frequently and staying under long.
Common and familiar in Mexico and Central America, and easy enough to find along the lower Rio Grande, this is a very rare bird in Arizona, and with the apparent demise of the long-faithful individuals that frequented two Tucson sites, these are the only Least Grebes known in the entire US outside of Texas.
Since their discovery last week, these two are reported to have built a nest, copulated, and laid eggs in front of the ornithovoyeurs. We couldn’t see the nest this morning; it may well have fallen victim to the same storm that kept us out of California Gulch. But the pair did stick close together, in obvious conjugal fondness, and once we heard them sing, a loud trilled duet like silver under the monsoon skies.
Shorebirds: Quality, Not Quantity
Posted by: | CommentsShorebirders are never satisfied: one day the water’s too low, the next day it’s too high. This morning was definitely one of the latter days, with the past couple of days of rain raising water levels at Avra Valley to a point that nothing but Black-necked Stilts could use most of the pools.
In fact, even counting the stilts and the Killdeer and the thirty or so Least Sandpipers cringing on the edges, there weren’t a hundred shorebirds out there this morning. But among them were a couple of minor prizes: an adult Stilt Sandpiper (a species that will be more and more common over the next weeks) and two adult hendersoni Short-billed Dowitchers, scarce birds in Arizona and usually detected only as juveniles.
The best time of year!
Like Avocets to Water
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American Avocet breeds in variable numbers on the Willcox Playa, about 80 miles east of Tucson, and July is a great time of year to see the thick-legged chicks on the shores of Lake Cochise. Survival rates seem to be low, no doubt a reflection of the happily high populations of coyotes and bobcats in the area, but still a few young avocets seem to come off every year.
The surviving chicks grow longer-billed and warier every day. While their parents are always anxious on the approach of a vehicle, very young avocets tend to just run slowly along the shore–but as they get older, the adults’ loud kluuiting seems to be contagious, and the chicks start to evade intruders, first by running more quickly, then by taking to the water with their parents.
It’s as if it took the little ones a few days to figure out what those webs between their toes were for.
The Fifty-first Supplement to The AOU Check-list
Posted by: | CommentsIt’s that season, and the new Supplement to the AOU Check-list (still so quaintly spelled a century and a quarter after the first edition!) appeared at BioOne yesterday.
The news of a few species “splits” affecting birders in the US and Canada was not unexpected–the only thing surprising, and perhaps a little disappointing to a resolute non-scientist, was that there weren’t more. In any event, we now officially have two whip-poor-wills, Mexican Whip-poor-will and Eastern Whip-poor-will, and the old “winter” wren is now recognized as three species, two of which–Pacific Wren and the remarkably poorly named Winter Wren sensu novo strictoque–occur in North America. “Our” black scoter is split from the Old World species and renamed Melanitta americana, vindicating good old Swainson a hundred seventy-five years after he described it; its English name is apparently uncertain at the moment, though the copy of the Supplement I printed out today calls it, logically and straightforwardly, “American Scoter.”
While species determinations speak only to identity, genera are all about relationships, and this Supplement is full of new views about what belongs with what. Canyon, California, and Abert’s Towhees are moved over to Melozone, which they’ll be sharing with the tropical ground-sparrows; only the three rufous-sided and Green-tailed Towhees remain in the cheerful-sounding genus Pipilo.
There are some significant innovations in the warblers, too, both Old World and New. Here in North America, Vermivora is greatly diminished, now including, if I count right, only Blue-winged, Golden-winged, and the ghost of Bachman’s Warblers. The handsome old genus Oreothlypis is resurrected to contain all the other erstwhile vermies and two tropical “parulas,” Flame-throated and Crescent-chested Warblers; visually and intuitively, those latter two have always been thought of as intermediate between the parulas and the old-style Vermivora, so it’s nice to see them sharing a taxonomic drawer. I just wish that we could change their English names, too, to echo the genus name: wouldn’t it be nice to go out and see some Orange-crowned Mountain-Chats? And just imagine what high school football teams in Tennessee could do with it.
Another pair of warblers, the waterthrushes, have now got their own genus, Parkesia, bearing the name of one of the last century’s greatest museum men and warbler experts. Ovenbird stays behind to brandish its tail in Seiurus, no doubt to the posthumous frustration of Eliot Coues, who argued long and hard that it should by rights have been spelled Siurus.
I tremble to report it, but it’s official now: Aimophila, that wonderful ragbag genus of wonderful ragbag sparrows, has been dismantled. Here in Arizona, only Rufous-crowned Sparrow is still an Aimophila, our others moved into the revived genus Peucaea. Five-striped Sparrow, always an uncomfortable nomenclatural fit, has gone back to Amphispiza, joining once again the visually similar Sage and Black-throated Sparrows. (No action on the possible split of Sage into Interior Sage and Bell’s Sage Sparrows.)
These changes, of course, I take personal: my favorite bird in the world, Rufous-winged Sparrow, can no longer serve as the eponym for this b-log or my drowsy little guide service. What shall I do? Kenn suggested renaming it “Peucaea Perambulations,” but I think maybe I’ll just let people think that I can’t identify Rufous-crowned Sparrow and leave it at that.
The revisions don’t stop at the level of genus, either. There are eleven new families recognized, including the re-elevation of Osprey and the gnatcatchers to family status; the longspurs and white buntings also get their own family, Calcariidae (and McCown’s Longspur goes its own way generically once again).
The Old World “warblers,” a miscellaneous bunch if ever there was one, are broken into many families: Cettiidae includes the bush warblers, Phylloscopidae the leaf warblers, Sylviidae the round-headed chattering warblers (now including Wrentit), and Acrocephalidae the reed warblers. Those new Eurasian families are followed in sequence by an American one, Donacobiidae: hurray for Donacobius, sometimes a wren, sometimes a thrasher, now confident enough to simply be itself.
Most far-reaching of all is the re-organization of a couple of non-passerine orders. Sunbittern and Kagu, two of the most extravagantly plumed birds anywhere, now get their own order, Eurypygiformes; I doubt that this particular innovation will last–higher categories generally want to be more densely populated–but that’s the solution of the moment. The falcons and the other diurnal raptors are split into two orders, falcons and caracaras keeping hold of the old Falconiformes and the rest inserted into a new Accipitriformes.
And then there are the storks and pelicans. Ciconiiformes relinquishes everything but the storks themselves; the herons and ibises are now part of the order Pelecaniformes, where they sit alongside the pelicans and form the suborders Ardeae (herons and bitterns) and Threskiornithes (ibises and spoonbills).
The committee giveth and the committee taketh away, and the old totipalmate swimmers are now split up into three orders: the pelicans and herons (that phrase will take some getting used to!), the Phaethontiformes (tropicbirds), and the Suliformes (frigatebirds, boobies, and cormorants). When I was a boy, back before they’d invented DNA and chemistry and all that, we learned that orders were defined by foot characters: we’ve come a long ways!
And changes will continue. The committee rejected proposals to split the scrub-jays and the curve-billed thrashers, but watch the “pending” section of the committee’s web page for new proposals–and look forward to next July when the next Supplement will be published.
Tyrants of the Desert
Posted by: | CommentsOne of the great morning sounds of the Sonoran Desert is the rolling growls of Brown-crested Flycatchers, common summer birds in our scrubby neighborhood.
This species is a late arrival in the spring and a correspondingly early departure in the fall; they’ll certainly be gone from our yard by the time I am at the end of the month.
For now, though, their whoops and hollers wake me up in the morning, and every once in a while we catch a glimpse of their long brown trails chasing through the trees.
