Hi Dave and all, I also find the breeding distribution of Black-throated Green Warbler perplexing.
It is common and widespread over what strikes me as an unusually broad array of forest types, giving absolutely no indication to my eye of any kind of specialized preference. Yet it is absent from many places that look superficially as good (or better, in terms of the density of conifers) as places where they are numerous. For example, in southern Rhode Island both this species and also Hermit Thrush breed quite commonly in extremely unimpressive-looking* oak woods with just a few pitch or white pines. And in this same area, BT Green Warbler also breeds in Atlantic White Cedar bogs, another southern-style forest type. But on nearby Long Island, these very same habitats (along the very same moraines) are completely shunned by Black-throated Green Warblers (and support just a very few Hermit Thrushes, which here are restricted to the very "best" Pitch Pine forests). Even more striking is the scarcity of both of these species in near-upstate New York (e.g., Westchester and Orange Counties, and elsewhere) in nice-looking Transition Zone woods. This disparity takes a lot of getting used to for anyone who has seen the kind of sterile and depauperate woods* they like in RI, but now that I get it, David's observations from Chenango County seem just a more extreme example of a pattern I see in a lot of places. I've always wondered if the limiting factor was not so much the vegetation type but some combination of temperature and humidity; southern RI probably has lower maximum temps at this time of year, owing to the ocean influence, than do many low-mid elevation places in upstate NY. In addition to these two species, Northern Waterthrush, Canada Warbler, Purple Finch, and other boreal-associated species also co-occur as breeders surprisingly close to the coast in RI, in utterly non-boreal forest types: http://ebird.org/ebird/hotspot/L732767?yr=all&m=6&rank=mrec&hs_sortBy=taxon_order&hs_o=asc http://ebird.org/ebird/hotspot/L335600/all/6 If this temp/humidity explanation is true, the absence/scarcity of these species on similarly ocean-cooled eastern Long Island is more difficult to explain but might be attributable to the very small and highly fragmented nature of its woodlands, in addition to their already emphasized low quality.* Anyway, these were my thoughts when I read this very interesting and inspiring report. I think I'll count some Ovenbirds somewhere tomorrow morning! Shai Mitra Bay Shore *It took me a while to come up with these euphemisms to replace the phrases I would use naturally when speaking . ________________________________________ From: bounce-120574834-3714...@list.cornell.edu [bounce-120574834-3714...@list.cornell.edu] on behalf of David Nicosia [daven102...@gmail.com] Sent: Monday, June 20, 2016 2:28 PM To: NY Birds; Cayuga birds; broomebi...@googlegroups.com Subject: [nysbirds-l] New Michigan State Forest NW Chenango County, NY: Swainson's Thrush and Lots of Warblers. Had a chance to bird New Michigan State Forest from mid to late morning Today, 6/20/16. This forest is a high elevation boreal-type forest which is quite rare in upstate NY outside the Adirondacks and Catskills. There are areas of dense NORWAY SPRUCES planted by the CCC groups back in the 1930s so much of this forest is dense and fairly mature. There are also areas of RED PINE within a more typical northern hardwoods type forest of SUGAR MAPLE, AMERICAN BEECH, CHERRY and other deciduous trees and scattered native BALSAM FIR and to a lesser extent EASTERN HEMLOCK. The deep spruce woods are homes to a large population (locally) of BLACKBURNIAN WARBLERS. In addition, you can find SWAINSON'S THRUSH here too along with WHITE-THROATED SPARROWS which again are quite rare outside our bigger mountains. Once thing that puzzled me was the lack of BLACK-THROATED GREEN WARBLERS and YELLOW-RUMPED WARBLERS. The most common warbler was the OVENBIRD but a close second was the BLACKBURNIAN WARBLER. Do BLACKBURNIANS out-compete BLACK-THROATED GREEN WARBLERS? Or was the lack of hemlock ravines more a factor here? I also was able to record the beautiful song of the SWAINSON'S THRUSH and append to my e-bird list which can be linked below. In any event, I drove for over 9 miles in this beautiful area and carefully counted as many birds as I could hear. My e-bird list is my best effort at an "exact" count. I was conservative and very careful not to double count. I was amazed that I totaled 69 BLACKBURNIAN WARBLERS in 9 miles and a whopping 86 OVENBIRDS with a total of 50 species. I took just under 3 hours. see e-bird list here.... http://ebird.org/ebird/view/checklist/S30317959 Dave Nicosia Johnson City, NY -- NYSbirds-L List Info: Welcome and Basics<http://www.northeastbirding.com/NYSbirdsWELCOME> Rules and Information<http://www.northeastbirding.com/NYSbirdsRULES> Subscribe, Configuration and Leave<http://www.northeastbirding.com/NYSbirdsSubscribeConfigurationLeave.htm> Archives: The Mail Archive<http://www.mail-archive.com/nysbirds-l@cornell.edu/maillist.html> Surfbirds<http://www.surfbirds.com/birdingmail/Group/NYSBirds-L> BirdingOnThe.Net<http://birdingonthe.net/mailinglists/NYSB.html> Please submit your observations to eBird<http://ebird.org/content/ebird/>! -- ________________________________ Take a picture. Write a caption. Win a prize. Where’s Danny the Dolphin today?<http://www.csi.cuny.edu/wheresdanny/> -- NYSbirds-L List Info: http://www.NortheastBirding.com/NYSbirdsWELCOME http://www.NortheastBirding.com/NYSbirdsRULES http://www.NortheastBirding.com/NYSbirdsSubscribeConfigurationLeave.htm ARCHIVES: 1) http://www.mail-archive.com/nysbirds-l@cornell.edu/maillist.html 2) http://www.surfbirds.com/birdingmail/Group/NYSBirds-L 3) http://birdingonthe.net/mailinglists/NYSB.html Please submit your observations to eBird: http://ebird.org/content/ebird/ --
