Date: Sat, 29 Jul 2000 06:52:30 -0500 Reply-To: Maryland Birds & Birding Sender: Maryland Birds & Birding From: rick Subject: Re: Black-Billed Cuckoo, Soldiers Delight Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" I agree with Bob Ringler's statement in his post about Black-billed Cuckoos in Maryland: "Black-bills are rare breeders outside of Western Maryland but could occur anywhere." The situation this year may be slightly more complicated. I subscribe to most of the state birding listservs and there are reports of Black-billeds from unexpected areas on many of them this year. It seems like a year in which they are appearing out of normal range in out of normal numbers. I say out of normal range because the edge of the range for cuckoos has always been a bit plastic, but there is another factor at work as well. There is growing evidence that both cuckoos are at least partly nomadic in the breeding season. The emerging view is that they arrive on the breeding grounds, assess the quality of the habitat (the abundance of tent caterpillars is thought to be the key), and if they do not find sufficient resource, start wandering. In most cases this means shifts in abundance within the known range, so it is hard to quantify. It has been common for more than fifty years, however, for observers to make comments like "Cuckoos were especially common this year, after being notably scarce last year." If most of the shifting occurs within the core of the range it is likely to pass uncommented on except for a few anecdotal stories. If there is an abundance, or a shortage, at the edge of the range, it is more likely to be noticed because the birds are normally scarce there and because there is a greater likelihood of birds pushing beyond the normal boundaries. On the basis of scattered, anecdotal, and incomplete evidence so far it seems possible that this is one of those years for Black-billed Cuckoo. It may also be one of those years for Yellow-billed, but we are not likely to notice it unless folks who are out a lot get the impression that Yellow-billeds are a little more common this year. Whether or not this theory holds up over time, a lot of people just beyond the southern limit of the expected range are finding Black-billed Cuckoos this year. Rick A human being is just a computer's way of building another computer: usually a better one. That is why computers will never replace human beings. We are their sex organs. - David Gerrold Rick Blom rblom@blazie.com 4318 Cowan Place Belcamp, Maryland 21017 (410)575-6086 Editor: BWD Skimmer (www.birdwatchersdigest.com) ======================================================================= To leave the MDOsprey list, send e-mail to listserv@home.ease.lsoft.com with the following message in line 1: signoff mdosprey ======================================================================= =========================================================================