Subject: Re: Western Kingbirds (was: Backyard Birding)
Date: Sep 13 11:29:57 1998
From: Michael Price - mprice at mindlink.bc.ca


Hi Tweets,

Gene Hunn writes:

>re. Mike Price's warning about possible confusion of late Western Kingbirds
>with Tropical/Couch's. Nearly every record of Tropical (presumably) Kingbird
>for the west coast are of birds at or very near the coast, typically after
>mid-October through November. A "Tropical" east of the Cascades might more
>likely prove to be a Couch's!

And Michael rises to the bait for his annual rant on the subject of
identification by assumption and the resultant distortion of the record-base.

Nearly every record of Tropical Kingbird Tyrannus melancholicus is from at
or near the coast because historically every silent kingbird (a majority of
such records) at the coast was assumed to be a Tropical rather than Couch's
Kingbird T. couchii, and recorded as such, instead of, more properly, the
genus-only 'Tyrannus sp.' or 'Tropical/Couch's-type', even in the absence of
species-diagnostic calls, hence the tautological consistency of 'Tropicals'
showing up along the coast. Identification by assumption. In fact, as the
presence of a Couch's Kingbird in California last winter illustrated, they
*can* occur on this coast.

I can't say it often enough: *if you don't hear the calls, you can't tell
the difference.* And if you can't tell the difference between two
nearly-identical species, proper record-keeping requires you to assign a
genus-only, not species, status to your sighting, thus recording a silent
Tropical/Couch's-type Kingbird as either 'Tyrannus sp.' or
'Tropical/Couch's-type Kingbird'. We do that as a matter of course for every
other genus which has closely similar species observed in our region in less
than diagnostic conditions--i.e., Manx-type shearwater, Craveri's/Xantus's
Murrelet, Murphy's/Cook's Petrel, Selasphorus hummingbird and so on--so it
perpetually baffles me why in this instance observers not only continue to
identify by assumption but also to advocate a dispensation for this
particular pair of species from standard record-keeping process.

Michael Price A brave world, Sir,
Vancouver BC Canada full of religion, knavery and change;
mprice at mindlink.net we shall shortly see better days.
Aphra Behn (1640-1689)