Dowitchers

There are two common dowitchers in the Bay Area:  The Long-billed Dowitcher, and the caurinus subspecies of the Short-billed Dowitcher.  Thus, our challenge is narrowed down to separating these two taxons, and we can pretty much ignore the other two subspecies of Short-billed Dowitchers.

Seasonal Variation

The first dowitchers arriving in July and August are adult female Short-billed Dowitchers in breeding plumage.  Most of the  Long-billed Dowitchers don't arrive until October, although a few trickle in earlier.  Most of the adult dowitchers have molted into alternate plumage by October.  Juveniles arrive in September - October, and some don't lose their colorful juvenile plumage until December.   For explanations of characteristics below, see references to left.

Characteristic	Long-billed	Short-billed
Bill length to head length	avg 1.9	avg. 1.6
Base of bill vs height after nostril	about 1.1	about 1.6
Loral Angle	about 5 deg.	about 15 deg.
Color of breeding plumage belly	Red-orange	White
Juvenile tertials	Gray with narrow edging	Broad cinnamon edging and internal marks

 

Helpful Info

For me, dowitchers are one of the most difficult shorebird ID challenges.   Here is some useful material.

References

Cin-Ty Lee and Andrew Birch, Birding 2006.
LA Audubon Talk, 2007

Greg Gillson, The Bird Guide, 1995 (updated).

Pekka Sarvela, Dowitcher Bills 1995 (a discussion that shows the longest bills belong to LB Dowitchers, and the shortest to SB Dowitchers).

Photographs