Date: Wed, 24 May 2000 18:10:19 -0400 Reply-To: Maryland Birds & Birding Sender: Maryland Birds & Birding From: Pete Webb Subject: RFI Bicknell's vs. Gray-cheeked flight calls Comments: To: marvadel@egroups.com MIME-Version: 1.0 Content-type: text/plain; charset=us-ascii RFI Bicknell's vs (Nominate) Gray-cheeked Thrush flight calls The last few days, I've been hearing numerous Swainson's thrushes (with the flight call a clear, rising "werp" reminiscent of spring peeper= s) and a number of Gray-cheeked type thrushes calling a burry "veer" which, unlike the Veery's call, is about a half-octave higher pitched than the Swainson's thrushes' calls. I have the misfortune of being without the software to use my sound card (lost the driver and don't remember the brand and model and don't care to spend the time disassembling my computer to find out) and have resorted to some old LP records to try to get the calls; I found numerous recorded Bicknell's calls on the Borror Thrushes record from the 80's and some additional ones on the Peterson East record (second edition, 1983) along with songs of both Gray-cheeked and Bicknell's thrushes (Borror record only). As mentioned earlier by others, the obvious difference in the song is the descending trill ending the song by Gray-cheeked versus the steady or rising trill on the final note of the Bicknell's. The song is on the Borror Thrush record, recorded in New York as were all the "Gray-cheeked"= , actually Bicknell's, calls on that record. I've found the song difference to be quite distinctive and in fact have heard the Bicknell's song only o= n that one record and never yet in the field. The recorded Bicknell's calls could be represented "veery" or "vry", a very brief call with equal emphasis on the fall and the rise, and "speer" or "veer", descending calls often with a chuff of some sort a= t the very beginning of the calls. The only call I found on record for the Gray-cheeked was in the beginning of some of the songs and was a similar "speer" call. I've listened to a local migrant Gray-cheeked Thrush across the street and in addition to its typical Gray-cheeked song the bird rendered calls which I thought to be an almost two-syllable "vee-eer" with the SECOND syllable lower in pitch and steady, rather than rising or falling in pitch. Like the recorded Bicknell calls, it's about a half-octave higher in pitc= h than the Swainsons call. Just to fill out the species, Veery calls are about the same pitch as the Swainson's (which are numerous enough to serve as a standard) and often a bit longer in duration with strong emphasized falling pitch, "veeeeer". Wood Thrush call notes, which I haven't heard the last few evenings, are a shorter, falling pitch, very abrupt "yert" in the same pitch range as the Swainson's. The veery note falls much further in pitch; the wood thrush "yert" doesn't last long enough to fall very far in pitch. I haven't ever heard any flight calls of Hermit Thrushes; I've heard a catbird-like twin-pitch squeal and a "churk" like a distant Red-winged Blackbird on records and in person in the field during daylight hours when the birds seemed to be using the calls to complain or scold (especially the "churk" call). In th= e field I've heard a third call similar to the squeal with only one pitch but haven't found that call on recordings. What I'd like someone with more information to share is a description, if possible, of what (if any) difference might be heard between the flight calls of Bicknell's and Gray-cheeked Thrushes. My selfish motivation: hopefully be able to detect= a Bicknell's flying by my yard at night and add it to my yard list. Pete Webb Baltimore, MD (USA) pwebb@bcpl.net (home, after 6) pew@niroinc.com (work, M-F 830-5) ========================================================================= To leave the MDOsprey list, send e-mail to listserv@home.ease.lsoft.com with the following message in line 1: signoff mdosprey ========================================================================= ===========================================================================