I think the conflicting impressions described below by these two highly experienced observers highlight the distinction between two distinct measures of bird occurrence: frequency and abundance.
Although I don't spend a lot of time doing winter birding in the Queens area Steve mentioned, I've participated in close to 100 CBCs from just east of there (Southern Nassau County), elsewhere on Long Island, and in coastal southern New England--and paid fairly close attention along the way to which species are considered tough to find in the various circles. I agree with Ken that Common Grackle is the least frequently encountered during winter of the three common blackbird species--a property that could be measured by the number of distinct entries on an individual observer's field sheets, the number of parties recording the species on a count, or the tendency for the species to be missed entirely on the CBC. But I also agree with Steve that Common Grackle, when present, sometimes occurs in much larger numbers than any of the others--a "feast or famine" pattern of occurrence. To test this, I've pulled the numbers from three regional counts that vary quite a bit in terms of habitat composition, but which average comparable species totals in the 120-130 range: Southern Nassau County, Montauk, and South Kingstown, RI. During the 40 years from 1971 through 2010, the likelihood that a species would be missed entirely was consistent with Ken's impression: Red-winged Blackbird was missed 1/40 NYSN, 0/40 NYMK, 1/40 RISK; Common Grackle was missed 12/40 NYSN, 10/40 NYMK, 5/40 RISK; Brown-headed Cowbird was missed 3/40 NYSN, 6/40 NYMK, 0/40 RISK But maximum abundance was more consistent with Steve's impression: Red-winged Blackbird 316 NYSN, 1540 NYMK, 551 RISK; Common Grackle 264 NYSN, 3399 NYMK, 2753 RISK; Brown-headed Cowbird 504 NYSN, 502 NYMK, 581 RISK Shai Mitra Bay Shore ________________________________ From: bounce-7662358-3714...@list.cornell.edu [bounce-7662358-3714...@list.cornell.edu] on behalf of Steve Walter [swalte...@verizon.net] Sent: Friday, January 14, 2011 8:16 PM To: NYSBIRDS-L@cornell.edu Subject: Re: [nysbirds-l] Connetquot River S.P. and West End/Jones Beach Birds (Suffolk/Nassau Counties) Ken, I just want to make a point about Common Grackle "rarity" in winter, depending on what you meant by "our area". Are you referring to the Captree CBC? There were 3000 of them on the recent Queens count. Most winters, a large flock roams the residential areas of northeastern Queens (rather than places that birders go to -- so they may get missed on the count). They usually stick around until the weather gets extreme -- sometimes well through the winter. This year, I suspect they may have pulled out after the first big snow -- I haven't seen them in a while, and my backyard has been in their crosshairs in the past. The Bronx-Westchester CBC has also seen large numbers in some years. Although local, Common Grackle may actually be the most numerous blackbird overall during the CBC period (sometimes longer into the winter) in downstate New York. Steve Walter From: ken feustel<mailto:feus...@optonline.net> Sent: Friday, January 14, 2011 4:17 PM To: NYSBIRDS-L@cornell.edu<mailto:NYSBIRDS-L@cornell.edu> Subject: [nysbirds-l] Connetquot River S.P. and West End/Jones Beach Birds (Suffolk/Nassau Counties) At a mostly frozen Connetquot River State Park this morning was an adult Bald Eagle. On the river there were 120 Common Mergansers. Behind the park offices there was a Northern Bobwhite feeding on the spillage from the feeders. It is a commentary on the two different directions that these two species population's are trending that I considered the Bobwhite the rarer species. A stop at Bayard Cutting Arboretum in Great River was not particularly productive, partially owing to the fact that the tidal portion of the Connetquot River was mostly frozen. i did however, see my first of season Common Grackle (the rarest blackbird in our area in winter based partially on CBC data). West End 2 did not have many birds but they were interesting ones. At the WE2 marina there were two Lapland Longspurs on the lawn west of the rest rooms. Approx. fifteen Common Repolls were wondering around the median. Eight American Pipits were feeding on the shoulders of the parkway. At JBSP Field 6 there was an adult Lesser Black-backed Gull on the beach with the common gull species. Despite the cold weather this morning, the afternoon was one of the nicer days so far this year (the birds helped, too). Ken Feustel ________________________________ Think green before you print this email. -- NYSbirds-L List Info: http://www.NortheastBirding.com/NYSbirdsWELCOME http://www.NortheastBirding.com/NYSbirdsRULES ARCHIVES: 1) http://www.mail-archive.com/nysbirds-l@cornell.edu/maillist.html 2) http://birdingonthe.net/mailinglists/NYSB.html 3) http://www.surfbirds.com/birdingmail/Group/NYSBirds-L Please submit your observations to eBird: http://ebird.org/content/ebird/ --
