Date: Mon, 11 Dec 2000 15:30:15 EST Reply-To: Maryland Birds & Birding Sender: Maryland Birds & Birding From: Marshall Iliff Subject: CBC season rarity pitfalls MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit MDOspreyers, With Christmas Bird Count season only days away (first counts will be this weekend) I wanted to send a quick post to raise the general consciousness about some common CBC errors. Often the best bird of the count season goes unidentified because the observers reported the bird as the "expected" species, without knowledge of which of several similar species is more expected! Often in winter, the common summer breeder is far less likely than a rare western vagrant. One of the most frustrating things to read about in the CBC results is an extraordinary unseasonal rarity that was poorly documented or probably misidentified as the "more expected" species. Below is a short list of potential pitfalls. If anyone sees one of these groups during a CBC, or is on a CBC where one is reported, PLEASE PLEASE PLEASE send a post to MDOsprey. Even if it doesn't turn out to be a mega-rarity, it is worth fully-documenting late records of any of these species. * Hummingbirds - I think we all know by now that a November-February hummingbird is exciting. If it isn't a mango, it may very well be a Rufous. The three November Ruby-throateds this year were unprecedented. * Swifts - I can't imagine what species of swift would be most likely, but suffice it to say that from November to March, any reports of Chimney Swift should at least rule out Vaux's and White-collared, both of which are known from Gulf Coast states during CBC season (while Chimney is unknown during that time). * Empidonax - Any Empidonax flycatcher should be thoroughly documented as the western species (Hammond's, "Western", Gray, Dusky) are at least as likely as eastern species (only Least is known from winter in this area, Acadian, Yellow-bellied or Traill's would be astounding!). Any Empidonax has an extraordinarily good chance of being a VERY rare bird - Maryland's three winter reports were all not differentiated to species, but with today's field guides, cameras, video-recorders, and tape-recorders, any "sp." would very likely get nailed down to species. I recall an "Empidonax sp." that was reported on the Salisbury CBC a few years ago, which was not reported.There has recently been a Hammond's Flycatcher in Pennsylvania... * Myiarchus flycatchers - Our only regular Myiarchuis flycatcher is the Great Crested Flycatcher, but Great Cresteds are virtually unknown in winter in the mid-Atlantic. In fact, after late October ANY flycatcher in that genus is far more likely to be ASH-THROATED than Great Crested. Brown-crested and Dusky-capped are still not confirmed from the East Coast, but might be posible as well. That said, ANY flycatcher in this group should be carefully documented (with attention to call and tail pattern) even if it is the "common" species. *Wood-Pewees - Pewees are essentially unknown in the Northeast between October and late April. Some rpeorts may pertain to Empidonax, but any claims should be thoroughly documented. It is anyone's guess which specie smight be most likely. *Swallows - Any martin would be extraordinary and may more likely be a South American species than our summer Purple Martin (my November martin in Kent County was frustrating!). A swallow that looks like a Cliff Swallow would probably more likely be a Cave Swallow, at least until April. Otherwise, our summer swallows do sometimes linger, with Tree being most common b7y far, followed by Barn and Rough-winged. Bank, along with martins, are unknown in this area by December. * Warblers - Black-throated Green Warbler reports should be checked for the possibility of similar Townsend's (on at Cape Charles, VA last winter) and Hermit. Any reports of Mourning or Connecticut Warblers should be checked for the possibility of the very similar MacGillivray's. * Tanagers - Western Tanager is at least as likely in December as Scarlet or Summer, and Hepatic Tanager is known from Indiana! * Buntings - Any Indigo Bunting reported should be checked for Lazuli, and even Varied, as there is a record of the latter from Ontario. * Orioles - While Baltimore Oriole lingers in the area every year, often at feeders. We should still take pains to examine each and every oriole as carefully as possible. Though identification is difficult, recent winter records from the East have included Hooded Oriole in Quebec, Scott's Oriole in Illinois (I think...), and STREAK-BACKED ORIOLE in Wisconsin!! * A few other species are perennially reported on CBCs but require excellent documentation before acceptance. Examples are Common Tern (several reports from OCean City CBC - NONE are well-documented); Semipalmated Sandpiper (Western and Least Sandpipers are regular in winter - Semis are almost unknown); Red-necked Grebe (possible but definitely over-reported on some counts); Broad-winged Hawk (almost unknown on the East Coast in witner and a prime candidate for confusion with Red-shouldered); Chipping Sparrow (over-reported on some Piedmont and Mountain counts where birders confuse them with American Tree Sparrows); and American Tree Sparrow (which, conversely, is over-reported on many Eastern Shore counts where they may be confused with Chippings or Fields). Worst of all are spotted thrushes. Every CBC season sees multiple reports of Veery, Swainson's, Gray-cheeked, and Wood Thrushes although virutally NONE are well-documented. Obviously most are the result of confusion with Hermit Thrushes, which are regular in winter. Any claim of any of the other species needs exceedingly good documentation to convince the skeptics such as myself. Don't let this call for documentation be discouraging and by all means go out and have fun - but please do let MDOsprey know if you find any whacky out of season birds on your counts. With so many people afield each CBC-seaosn rare birds ALWAYS turn up somewhere, and many of us would like to share in the excitement and insure that the birds are well-documented for posterity. Good CBCing, Marshall Iliff miliff@aol.com Ocean City, MD ======================================================================= To leave the MDOsprey list, send e-mail to listserv@home.ease.lsoft.com with the following message in line 1: signoff mdosprey ======================================================================= =========================================================================