[obol] Re: Calidris ID help (Least vs. Long-toed)
- From: Shawneen Finnegan <shawneenfinnegan@xxxxxxxxx>
- To: "obol@xxxxxxxxxxxxx OBOL" <obol@xxxxxxxxxxxxx>
- Date: Tue, 28 Oct 2014 09:39:51 -0700
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
Other related posts:
