The idea of "migration corridors" is a misnomer. It would be so much easier if true but unfortunately it does not appear so. There is a perception (probably true at least in some cases) that major north-south river corridors have a greater concentration of migrants than random chance. But, for most species migration occurs on a broad front. This is different by species, season, and often by sex and age. There is strong evidence that migration does "funnel" into major stopover habitats such as the Lake Erie Marshes. But, there are questions to be answered there as well. How far away does funneling begin; is it more related to remaining habitat and lake effect just to mention a couple. Evidence does indicate "migration routes" by species are and can be influenced by both biological (age/sex) and environmental (weather) factors. Some diurnal migrants (raptors) do exhibit some relationship to wooded corridors such as rivers which provide stronger thermals than the surrounding agricultural environment. Was this true 300 years ago? Waterfowl and shorebirds are known for high migration passage unrelated to local habitat below. Their guidance comes through other means with a destination programmed in. Songbirds migrate from diverse starting points, often in loose flocks to wintering areas that are also diverse in location, primarily at night when land features are minimal in guidance value. There is not one magic answer or map. So many of today's threats to our birds want these simple maps, but sadly it just isn't that simple. There is so much more we need to understand to provide the protection and conservation of the avian world that we are rapidly altering. Mark Shieldcastle Research Director Black Swamp Bird Observatory 13551 W SR 2 Oak Harbor, Ohio 43449 419-898-4070 www.bsbobird.org www.ohioyoungbirders.org www.biggestweekinamericanbirding.com Become a fan of BSBO & Ohio Young Birders Club on facebook at: www.facebook.com/bsbobird www.facebook.com/ohioyoungbirders Follow BSBO on Twitter: www.twitter.com/bsbobird -----Original Message----- From: Ohio birds [mailto:[log in to unmask]] On Behalf Of Hutson, Timothy B Sent: Monday, October 24, 2011 12:42 PM To: [log in to unmask] Subject: [Ohio-birds] major Ohio migration routes Just wondering if there are any resources out there that identify major migration routes throughout Ohio. I'm curious to see if the routes taken by the various species are known and documented. I would assume that shore/water birds have favored routes (perhaps along river corridors) but that temperate migrants may just flood south in the fall. I just don't know. Thanks Tim ______________________________________________________________________ Ohio-birds mailing list, a service of the Ohio Ornithological Society. Our thanks to Miami University for hosting this mailing list. Additional discussions can be found in our forums, at www.ohiobirds.org/forum/. You can join or leave the list, or change your options, at: http://listserv.muohio.edu/scripts/wa.exe?LIST=OHIO-BIRDS Send questions or comments about the list to: [log in to unmask] __________ Information from ESET NOD32 Antivirus, version of virus signature database 6571 (20111024) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __________ Information from ESET NOD32 Antivirus, version of virus signature database 6571 (20111024) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com ______________________________________________________________________ Ohio-birds mailing list, a service of the Ohio Ornithological Society. Our thanks to Miami University for hosting this mailing list. Additional discussions can be found in our forums, at www.ohiobirds.org/forum/. You can join or leave the list, or change your options, at: http://listserv.muohio.edu/scripts/wa.exe?LIST=OHIO-BIRDS Send questions or comments about the list to: [log in to unmask]