Hi Tom & Greg (and other interested parties),

If you are asking whether a Black-billed Cuckoo can give an accelerating
clatter-call similar to a Yellow-billed the answer is yes. The
Black-billed's clatter-call is faster and more liquid sounding than the
wooden-block clatter of a Yellow-billed but it is also very similar. The
individual notes of the Yellow-billed's clatter are more discrete and sound
more hollow, the clatter at the end is also much less musical than the
Black-billed's and thus more gutteral. The coo calls are quite different and
are well-recorded on standard bird song source-recordings. Black-bills give
the familiar rapid triplets "cu-cu-cu" whereas Yellow-billeds give a slow,
well-separated series of low moaning "coou" notes. Also check out "Flight
Calls of Migratory Birds" (by William R. Evans and Michael O'Brien,
available from www.oldbird.org) for cuckoo flight calls (often given by
nocturnal migrants). If you are already aware of the vocal similarities and
differences I discuss I hope others on VTBird might be able to use my
comments.

Any hybrid should show intermediate plumage between its parent species. If
your bird looks pretty much like a Black-billed Cuckoo, I'd wager it is a
Black-billed.

Good Birding,

Walter Ellison
MD-DC Atlas Coordinator - MOS
23460 Clarissa Road
Chestertown, MD 21620
phone: 410-778-9568
e-mail: [log in to unmask]

"A person who is looking for something doesn't travel very fast" - E. B.
White (in "Stuart Little")

"Are there *ever* enough birds?" - Connie Hagar as quoted by Edwin Way Teale
in "Wandering through Winter"

----- Original Message -----
From: <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, June 10, 2005 11:31 AM
Subject: Re: [VTBIRD]


> Did a brief Google and found an alleged hybrid written up in The Wilson
Quarterly a quarter century ago. ID was done from a skin so the burning
question Greg and I are faced with - can a bird with largely Black-billed
field marks sing the song of a Yellow-billed?
>
> Tom Barber