[obol] Re: Calidris ID help (Least vs. Long-toed)
- From: "Wayne Hoffman" <whoffman@xxxxxxxx>
- To: <shawneenfinnegan@xxxxxxxxx>, <obol@xxxxxxxxxxxxx>
- Date: Tue, 28 Oct 2014 10:56:15 -0700
Hi –
One of the difficult lessons here is that when we really examine them
carefully, Least Sandpipers are incredibly variable. They vary in posture,
head pattern, leg and toe proportions, bill size and shape – you name it. I
bet if we look long enough we’ll find some birds with pale bill bases that
otherwise look more like Leasts then Long-toes.
I have no personal experience with conclusively identified Long-toed Stints,
but from examination of photos, I suspect the same is true for them – highly
variable as well.
I often imagine the difficulty a birder in Thailand, say might have poring over
flocks of peeps trying to pick out a vagrant Least Sandpiper, and periodically
finding birds that look “different” from Long-toes, but not able to nail down
any as definite Leasts.
Wayne
From: obol-bounce@xxxxxxxxxxxxx [mailto:obol-bounce@xxxxxxxxxxxxx] On Behalf Of
Shawneen Finnegan
Sent: Tuesday, October 28, 2014 9:40 AM
To: obol@xxxxxxxxxxxxx OBOL
Subject: [obol] Re: Calidris ID help (Least vs. Long-toed)
All:
I would say this is a Least Sandpiper, but this is a very difficult ID that has
stumped the best, particularly in basic plumage. Leasts can stretch up
regularly and look tall and upright which throws people off. Bob Archer brings
up some interesting points, but doesn't mention face pattern and lower bill
base color, which is the first thing I look for.
Long-toed Stints, particularly juveniles, have a different face pattern that
differs from Least in that the dark crown extends to the base of the bill and
connects with the dark eyeline, such that the white supercilium doesn't reach
the base of the bill. It creates a "J". This is less pronounced in basic
plumage. The supercilium on Least extends to the base of the bill. This bird
shows a faint facial pattern with some duskiness at the base of the bill at the
forward part of the supercilium.
The other thing is that Long-toeds usually, but not always, have a pale base to
the bill, which this bird does not and vice versa with Leasts. There is mud at
the base of this bird's bill on its right side, but not on the left which shows
the bill to be very black.
Leg length can be hard to determine because of Least's propensity to crouch.
Unless they stand up and look alert like the bird in question, seeing how long
the upper half of their legs are can be difficult to see.
The first thing I always do is hit the books and internet search for photos of
both species.
Monte Taylor has a number of photos of LTST on his website at:
http://www.tsuru-bird.net/a_species/stint_long-toed/
Years ago Rich Stallcup thought he had found a Long-toed in Marin County, CA,
which was finally deemed a Least Sandpiper. See video/blog by Keith Hansen who
took lots of video of it below. The record was never submitted as I believe it
was finally deemed to be a Least Sandpiper. But it shows just how hard these
can be.
http://thebloggerhead.wordpress.com/2009/10/27/interesting-sandpiper-has-birders-talking-learning-considering/
Off to work. No more time to contemplate this.
Shawneen Finnegan
Portland, OR
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