There is a great deal of random variation in bird population and range. What this means is as with all things in nature there are changes that occur within the natural system which effect populations and ranges. These changes are normal and not due to an outside assignable cause. It is impossible to draw any valid conclusions without a large data set which should include 30 years worth of data for a particular location. While there is no dispute about this, it is unpopular, even among some who claim to be doing science, because it does not support the desired conclusion, and cannot be quickly confirmed using regression based analysis, which is ill suited to population based studies, nor can it be done within the time frame of studying for an advanced degree. That said there is no dispute about anthroprogenic global warming, but it is not clear how that overall change is effecting the local climate in the Cleveland region. A rather long winded introduction to my own anecdotal observation of no decline and perhaps an increase in Rose-brested Gosbeak numbers this year in the forests on the Allegheny plateau to the east of Cleveland. In forest habitat they are, along with the Wood Thush, very common to abundant. I mention the Wood Thrush, because this species has allegedly declined by 50% in the past 30-40 years. I see no evidence of this, and as Peterjohn reported, they are to be found anywhere there is complete canopy. One has to wonder what happened to these woodland species in the mid 19th century when much of the eastern US was deforested for agriculture and commercial exploitation of timber resources? Haans On Tue, May 27, 2014 at 12:34 AM, Laura Peskin <[log in to unmask]>wrote: > Though I am a less-than-stellar birder, it seems that I have not heard or > seen a rose-breasted grosbeak around Cleveland in a great while. At the > same time I have seen all the other common birds. Are rose-breasted's > nesting populations shifting northward due to warming trends ? I single > out the grosbeak because until recently it was a constant May/ June singer > around the yard. > > Laura > > ______________________________________________________________________ > > Ohio-birds mailing list, a service of the Ohio Ornithological Society. > Please consider joining our Society, at > www.ohiobirds.org/site/membership.php. > Our thanks to Miami University for hosting this mailing list. > > > You can join or leave the list, or change your options, at: > listserv.miamioh.edu/scripts/wa.exe?LIST=OHIO-BIRDS > Send questions or comments about the list to: [log in to unmask] > ______________________________________________________________________ Ohio-birds mailing list, a service of the Ohio Ornithological Society. Please consider joining our Society, at www.ohiobirds.org/site/membership.php. Our thanks to Miami University for hosting this mailing list. You can join or leave the list, or change your options, at: listserv.miamioh.edu/scripts/wa.exe?LIST=OHIO-BIRDS Send questions or comments about the list to: [log in to unmask]