I have read with interest recent posts relating to early migration and questions on populations this year. While these are different issues it is possible there is an interrelationship unknown to us at this time. While the subjects are much more complicated than space allows here, I wish to get some thought processes started in bird behavior and their conservation needs. Bird numbers were down considerably this spring along the Lake Erie coast, nearly 40% from average. This appears to have been widespread with migration stations from Minnesota to the east coast indicating similar reductions. The cause isn't as easy to ascertain unfortunately. While there is always some variation in where birds pass through and in what volume, this across the board reduction is reason for concern. We will be watching fall age ratios as we begin the fall migration banding program here at Black Swamp Bird Observatory. A major increase in young to adult ratios may indicate low breeder numbers as suggested by spring passage numbers and the expected high productivity associated with a rebounding population. Time may allow us to look back for the answers we seek. While we have spring migration down to a fine art in timing (you name the species of passerine and we can give you the time frame most likely to encounter it) fall migration has remained a bit more difficult. Different environmental parameters and species motivators are in action during the southward migration than what we see in the spring. Spring is governed by day length and reproductive behavior. For fall, there is the primary driver of day length, but a host of other factors such as age, sex, actual breeding timing, food resources, post-breeding condition, and several actions that could be considered forms of "migration". The biggest complications for observers of theses "migration movements" is post-breeding dispersal and fledgling dispersal movements or "migration". These may represent a staging of local birds or an actual migration. This "migration" is generally northward in direction. In most locales this isn't noticeable, maybe a sudden influx of birds or of an individual not known to breed in an area. Along the Lake Erie coast these "dispersal migrations" are quite evident. These northward movements of young of year birds are observed in almost all bird groups. All recoveries of banded Ring-billed Gulls (RBGU) following fledging near Maumee Bay colonies were in the Saginaw Bay area of Michigan until late summer when birds retuned to Lake Erie and continued their "true migration" to the Atlantic Coast. Color-marked Purple Martins (PUMA) from over 40 colonies in east-central Ohio were recorded moving northward through the colonies and then at the large roost at Presque Isle, PA in the early fall before heading in a "true migration' to South America. Large influxes of passerines from Yellow Warbler (YWAR), Baltimore Orioles (BAOR), Eastern Phoebes (EAPH), and swallows can be observed each August along the Lake Erie coast. Understanding the different movements birds have increases our understanding of their behaviors and can lead to a greater understanding of their needs and hence improved conservation. While not all, much of the threads I have read on this list-serve appear to represent this local or northward dispersal migration common for late July and early August. Identification of these concentration or "staging" areas are an important part of their life cycle needs and can be extremely important in bird conservation now and into the future. Mark Shieldcastle Research Director Black Swamp Bird Observatory 13551 W SR 2 Oak Harbor, Ohio 43449 419-898-4070 <http://www.bsbobird.org/> www.bsbobird.org <http://www.ohioyoungbirders.org/> www.ohioyoungbirders.org <http://www.biggestweekinamericanbirding.com/> www.biggestweekinamericanbirding.com Follow BSBO on Facebook! <http://www.facebook.com/bsbobird> www.facebook.com/bsbobird Follow BSBO on Twitter - www.twitter.com/bsbobird ______________________________________________________________________ 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]