San Diego Natural History Museum--Your Nature Connection[San Diego County Bird Atlas Project]

WRENDERINGS
Reports from the Field
Winter 2000

A Murder Mystery
You Never Know...the Story of San Diego County's First Family of Brown-crested Flycatchers


A Murder Mystery

On 9 June of this year I was walking my property line (middle of square G9 in the Merriam Mountains north of San Marcos), listening and looking for resident summer birds. I heard a familiar "chuck, chuck." Looking across a hillside of recently cut curly willow plantings I found a single California Thrasher foraging in the leaf litter. I looked away for a moment, and when I returned to viewing there were two thrashers locked in combat. They jabbed bills at each other, wings slightly outspread and wingtips dropped to the ground. Becoming a single ball of feathers and dust, they rolled down the hillside into a clump of upturned roots. Meanwhile, a third California Thrasher appeared as the battle was raging. I assumed it was the mate of one of these birds. She (?) paced and followed at a short distance from the fray.

I soon realized I was viewing the demise of one of the thrashers. The bird on top kept plunging head and beak into the body of the other. Its bill glistened with tissue and blood. The third bird became aware of something and scurried up the hill, disappearing into the brush. The victor finally left the dead victim and climbed onto a pile of brush. It spent a good deal of time rubbing and cleaning its bill on the branches. With feathers still rumpled from the battle it climbed atop the tallest branch and continued calling "chuck, chuck."

I retrieved the carcass and froze it, and later delivered it to Phil Unitt at the museum. Dissection revealed that it was a male, but, interestingly, not in breeding condition. Its testes were only slightly enlarged, and its annual molt was just beginning with replacement of the innermost primary. Was its fatal mistake wandering into the territory of a male still pumped up with hormones? How much more respect does the California Thrasher's sickle now command!

--Carol McKie Manning


Brown-crested Flycatcher, sketch by Nicole Perretta
Brown-crested Flycatcher
sketch by Nicole Perretta

You Never Know ... the Story of San Diego County's First Family of Brown-crested Flycatchers

Funny how things work out: I was supposed to go to a wedding on the 26th of August, but I didn't get an invitation (there are several ways to interpret that...). So I was freed up to do a dry run for a Point Reyes Bird Observatory Birdathon into which Roy Poucher talked first me, then Geoff Rogers and Phil Unitt. We had figured out a tentative route, so I volunteered to try it out and time everything since I'd be driving anyway. My part of the dry run began at Old Springs Road (southwest corner of square F26) at sunrise, where the LeConte's Thrashers were still singing, and not in response to a tape.

From there I headed over to the Roadrunner Club in Borrego Springs (F24), pulling in across from "Swan Lake" about 6:30 AM. (I have since discovered that one must park in the visitors' parking area.) I dutifully checked my time as I started toward the lake. Little did I know that my timing would be screwed up royally when I heard a sharp pik pik pik pik! from the eucalyptus trees, followed by a harsh breeeer! The more I listened, the more I thought, "Naaa—that can't be a Brown-crested Flycatcher!" But as I hunted the calls down and caught sight of a Myiarchus flycatcher flying back and forth between the tall eucs (and there were at least two chattering at each other), I knew something was different. I debated running back to the car for the camera. Normally I never leave the car without it, but this time I figured there wasn't enough sun yet to photograph anything and nothing unusual will show up—right! But before I could return for the camera, one of the birds flew into one of the shorter, thicker eucs right by the road, and I was able to get a smashing view of the bird: it initially had its back to me, and the first thing to strike me was its big, bushy crest that gave its head a somewhat elongated look, then that honker of a bill with a good-sized hook on it: much bigger than anything I've ever seen on an Ash-throated. It looked as though it had just a touch of flesh at the base of the lower mandible, and the wing bars were quite pale and distinctly marked, making me think "juvenile", but I put that out of my mind right away, thinking that one miracle was plenty. How soon would I be proved wrong on that! The bird then turned around and showed me the underside of its tail, where, sure enough, the rufous webbing went straight down to the tip. I knew that didn't rule out a juvenile Ash-throated Flycatcher, but between that crest, that schnozz, and most importantly that voice, there was no doubt in my mind we had a Brown-crested on our hands!

A note on vocalizations: the Myiarchus flycatchers are definitely a group where it pays to be familiar with their language. Actually, in my opinion, having only one common Myiarchus in San Diego County, the Ash-throated Flycatcher, makes the problem easy, because it offers the opportunity for birders to become intimately familiar with one species' calls. That way, when you travel to southeast Arizona (where the Brown-crested is supposed to be) and hear these birds vocalize, you notice the difference! To my ears, the Brown-crested's calls are a median between the soft-spoken pips and burrs of the Ash-throated and the loud, far-carrying wheeps and harsh, obnoxious reeeps of the Great Crested Flycatcher from the east. Compared to the Ash-throated's, the Brown-crested's calls are much stronger, harsher, and often (for the musician out there) come in a rhythmic pattern of an eighth note followed by two sixteenth notes, followed by another eighth, with the accent on the first note (WHEER didi do!). In the Rio Grande Valley, however, one must be careful, because both the Brown-crested and Great Crested show up there, and both can have very strong wheeep calls.

At any rate, to make the rest of the story short, I called Guy McCaskie, who came out the next morning with Paul Jorgensen, and they confirmed the identification, finding the fledglings, their tails not yet fully grown, as well as the adults. The following day, Jack Schlotte took photographs of them, and several people saw the adults ferrying insects to the fledglings and thrusting them down their throats. So there had been a second miracle: not only a county record for the bird but for breeding as well, and at an amazingly late date. Had the two adults been wandering alone most of the summer outside of their normal range before finding each other—and some yet unidentified nest site—at the Roadrunner Club? It just goes to show that you never know what you'll run into, even in the Anza-Borrego in the heat of the summer.

--Mary Beth Stowe

Brown-crested Flycatcher sketch by Nicole Perretta

birdatlas@sdnhm.org

Winter 2000 Wrenderings | Wrenderings Archive | Bird Atlas Introduction