What Willet Be?

The Willet, although incredibly abundant and widespread, is still in many ways a mysterious bird.  Although it's been known for over a century that there are two distinct populations of willets (one which breeds coastally in eastern North America, and another that breeds in the western interior), much remains to be sorted out about the two populations.  Certainly a lot of the popular information on the species and its two populations is streamlined to such a degree that it promotes misunderstanding and bad science.  In the case of this species, a little knowledge can be a dangerous thing.  Overzealous birders often confuse the material in soft identification articles with hard, reliable data, and take it into the field.  As a result, myth has been mixed with the canon of knowledge about this species.  Thus, some birders today believe that any and all willets can be identified as either the Eastern or Western subspecies based on morphology or seasonal distribution.

Most authoritative works on Willets, shorebird guides, and even the above-mentioned soft ID articles try to caution readers against being too hasty in attempting to identify all willets to subspecies.  However, reckless birders often fail to heed those caveats.  For instance, although most western and eastern willets show a difference in size, some birders ignore the hard, quantitative data showing that size overlap does indeed exist.  Many birds are simply in the middle.  As well, not every fieldmark is waterproof.  Judging between the two subspecies can boil down to subjective interpretation of characters.  Again, many birds are obvious; however, it's the middle of the spectrum that kills good science.

The timing of migration is also used by some as a means of separating the two subspecies, a fact which in itself is dangerous.  The popular mantra is that eastern adults are gone by the end of July, while juveniles sometimes stay until mid-August, rarely into September.  When this information was first published, it was acknowledged to be tentative.  However, with each subsequent retelling in popular birding literature, this suggested window of passage has assumed more of an aura of established fact.

Whatever the case, the juvenile above was photographed last Sunday (August 14) as it loafed in the open with several others like it on the muddy banks of the highway-side canal between the Cameron ferry and Holly Beach.  It seems pretty safely on the Eastern side of the spectrum.  It might have been interesting to see how many such Eastern Willets a stretch of this canal contained, but I was more interested in investigating the beach.  Luckily, this bird and its companions were impossible to miss from the road even at highway speed and I was able to back up to take its picture.  

Once on the beach, several other interesting Willets were seen.  One was a very large, "Western"-sized bird with very dense markings below that called the plumage of Eastern Willet to mind.  Another was the bird below, another Eastern which appeared to be well on the way to basic plumage.  I spent a good while examining this bird, as did a few other curious birders that seemed to be wondering what the big deal was.  I would have liked to have studied it more closely; however, traffic on the beach compelled me to move on.  Given the cooperative nature of this bird and the great looks available, I'm sure the other birders present were also able to identify this bird to subspecies by size and bill shape.                                                                                                                                                                      

    

Eastern Willet, Ruddy Turnstone, Black-bellied Plover, 2 presumed  Western Willets.   Note size difference between willet on left and willets on right.  

Some birders might debate the identification of the birds above as "Eastern" Willets.  I welcome the discussion and the chance to explore the question of Willet ID in greater detail.

Hopefully good science will replace the need for conjecture soon.  It will be nice when a reliable picture of the Willet's presence emerges.