Friday, August 29, 2014

The Willet Conundrum and SW Florida Shorebird Review

[SW Florida Coastal Hotspots. August 2014]

Shorebird identification presents many challenges to both the initiated and the uninitiated -- Short-billed vs. Long-billed Dowitcher; Black-bellied Plover vs. Golden Plover; Baird's Sandpiper vs. White-rumped Sandpiper; Semipalmated vs. Western Sandpiper; to name but a few identification conundrums.

However, should inter-species identification be insufficiently daunting, the courageous birder is encouraged to test their skills at disambiguating shorebird subspecies. And, a great example of this genre is the one that involves distinguishing between Western Willet and Eastern Willet (both sufficiently different that their future candidacy for full-species status is deemed likely and perhaps even inevitable; see Sibley's Article).


Eastern Willet observed at Tigertail Beach, Marco Island, on 7/9/2008

Both Eastern and Western Willets are observed in SW Florida -- the former only in passage (this blogger has seen them in Fall migration from early July through early August although I have not recorded the dates of their passage in Spring) and the latter as a Fall and Winter visitor.

Looking at the Eastern Willet (in alternate plumage) above, two things stand out: the extensive marking and barring on the back, breast and flanks and the overall brown coloration.


 Western Willet seen at Lucy Evans Baylands Preserve, San Francisco Bay, on 3/29/2013


 Western Willet seen at Laguna Beach, coastal Orange County, on 4/1/2013


In contrast, the Western Willet appears decidedly grey rather than earthy brown and the markings are less extensive (especially on the back and flanks). Of course, when the birds are not in alternate plumage, these clues are insufficient and other diagnostic features must be employed.

Eastern Willet observed at Tigertail Beach, Marco Island, on 7/9/2008

And, these additional features are: the bill (Eastern's is stouter and more compact; Western is longer and tapers to a thin point); the shape of the crown (Eastern's is flatter compared to Western which is rounder); and body structure (Eastern's is slimmer and shorter necked).

With this backdrop, the following Willet, which was observed in early August at Bunche Beach, should not present much of a challenge:


Willet seen at Bunche Beach

And so now the question: which subspecies is it?

More on the differences between the two Willet subspecies may be found here: Aba Article on Willet Subspecies.

Willet seen at Bunche Beach

Lastly -- this Willet in basic plumage also provides a good example -- the bill tapers to a fine point, the crown is nicely rounded -- and therefore, this fits the characteristics expected of the Western subspecies.

Other shorebirds observed included Short-billed Dowitcher:


Short-billed Dowitcher seen at Bunche Beach

Mercifully, Long-billed Dowitchers favor freshwater and are not observed coastally making every Dowitcher observed at Bunche Beach, by default, a Short-billed.

And, Marbled Godwits whose numbers are rising at this venue:


Marbled Godwit seen at Bunche Beach

Spotted Sandpiper at Tigertail was observed with spots rather than sans spots (as in basic plumage):


Spotted Sandpiper seen at Tigertail Lagoon
 
The ubiquitous Semipalmated Plovers were seen scurrying about:


Plus, Black-bellied Plover:



Western Sandpiper:



Non-shorebirds included Burrowing Owl, Roseate Spoonbill and White Ibis:

Burrowing Owls are reliably observed on Marco Island on vacant lots:



Roseate Spoonbill seen at the Lagoon:


Roseate Spoonbill in "Sky Pointing" pose at Tigertail Lagon
 
White Ibis:

And, finally, a bonus reptile -- a Florida Box Turtle:

Florida Box Turtle seen at Tigertail Beach (monochrome)

Willets abound on our beaches and while they are generally overlooked because of their abundance, a closer look at the right time of year can tell which are the 35% of the total population that are classified as Eastern Willets and are just passing through; and, which are the other subspecies -- the more numerous Western Willets that will overwinter here.

2 comments:

  1. At opportune times I have seen both Eastern and Western Willet together at Bunche Beach Preserve, Hemant. The Western Willet, when compared side by side with Eastern Willet, is noticeably larger. The numbers of Marbled Godwit appear to be improving indeed. It is not uncommon to see dozens of them, although over a long stretch of the beach.

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  2. I'd love to get both subspecies in a single frame, Bob -- it would make the differences between them so much clearer.

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