[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: DNA and Willow Flycatcher




On Sun, 8 Jul 2001, Jack Peachey wrote:

[snip]
> 	I'm wondering if such characteristics are indeed subtle, couldn't they
> really be the same species.  If I see a Willow/Alder type that doesn't
> sing, its a "Traill's Flycatcher" to me. And who knows, perhaps that's what
> it really is even if it does sing!

I guess what's important is whether the differences which are so subtle to
us are subtle to the birds, too.  Can they tell each other apart (and do
they care) when it's time to breed?  Although Robert Zink might disagree
with me, that's still probably the most widely accepted definition of a
bird species.

> 	With regard to your comment
> "Claiming that a single bird sang both Willow and Alder songs is sort of
> like claiming to have seen a Shy Albatross on the back 40." 
>  True the bird I saw was not tape recorded. However I think that your
> comment is irresponsibly dismissive and doesn't apply in my case. I'll
> relate the incident. 
> 	 I was birding solo at Conasconk Point, Union Township, Monmouth County in
> early May in the early 80's. I found an empidonax on a snag of a bush. As I
> watched, it sang the "fetz-beuw, Willow song and the "fee-bee-o" Alder
> song. I want to emphasize I saw it sing both songs. Head thrown back, bill
> open, throat vibrate. It sang more Willow than Alder type songs, so I
> counted it as a Willow.   

Well, I have great respect for your powers of observation, and I was
probably more than usually awkward in phrasing my point.  I wasn't trying
to pass judgement on any particular observation, but more to argue that
when it comes to evaluating and making records of bird songs, especially
when dealing with something that "shouldn't" happen, none of us humans are
very good at it without mechanical assistance.

The shy albatross analogy was admittedly farfetched (although New Mexico
got it's first red-billed tropicbird record when someone picked one up in
a parched agricultural field, so never say never).  But I'd consider one
Empidonax singing songs of two "species" very unlikely, given that the
Flycatchers that have been tested show no song learning at all - unlike
most passerines, what tyrant flycatchers sing sing is what they were born
with.  I could much more easily believe an indigo bunting singing a
warbler song or a robin singing a whippoorwill song.  My assumptions about
flycatchers may be wrong - perhaps singing behavior in flycatchers is more
plastic than we realize, and observations like the bird in NJ will help
document that.

But consider that weak albatross analogy further - if someone did see an
albatross out of place, given a good enough look, he or she could describe
all kinds of objective details - color of the wing linings, patterning of
the coloration around the head, proportions, soft part colors, and so on.  
But when dealing with bird sounds we humans don't have that facility.  We
can use words like buzzy, thin, rich and syruppy, and so on. But fine
details, the kind you can see on a sonogram and that birds themselves can
perceive, are mostly lost on us, and the description by necessity usually
falls back on "sounds like an X" or "doesn't sound like a Y."  I think
it's too easy to miss important distinctions that way.  It may sound
*more* like an X than any other bird the observer knows well, but that
doesn't always mean it sounds exactly like an X.

Yankee that I am, I know (or used to know) northern warbler songs probably
as thoroughly as anyone - put me in the Maine woods and I'll identify
literally every song quite easily, including little known variants of
Blackburnian Warbler songs, dawn songs of Chestnut-sided Warblers, and all
sorts of other oddball stuff.  I spent a summer counting breeding birds
there, after extensive training from a specially made tutor tape the
spring before, and all summer, I was never fooled by a warbler song (but
please don't bring up the Boreal Owl/Snipe incident :-).  But back to my
point, if you had stuck a vagrant Hooded Warbler in with the locals, I'd
probably have passed it off as a Magnolia or Redstart or something.  As
well as I thought I knew those songs, I'm sure I wasn't really hearing all
the details of the songs - all that training was just enough to lump songs
into categories - thin, repeated on one high pitch = Cape May.  Thin,
repeated, trailing off slightly at end = Bay-breasted.  High, rising
kachee kachee kachee kachee = Blackburnian variant.  I was picking up on
one or two characteristics of the songs, and missing most of the
characteristics.

When I look at a sonogram of a species whose song I know well (like Yellow
Warbler, or Carolina Wren), I'm always just amazed at all that's going on
in there.  I'd never know it without a sonogram.

So I won't be drummed off the list for wanton offtopicness, Gary Phillips
took me birding in lowland forest near Conway, SC this morning and many of
those southern warblers were still singing, including Hooded, Parula,
Black and White, and Swainson's, which Gary produced, essentially
immediately and on demand.  I was very impressed, with both the birds and
the ease with which Gary rounded up some Swainson's.

Chris Hill
Coastal Carolina University
Conway, SC