Thursday, August 18, 2016

Michigan's First Sharp-tailed Sandpiper! - 13 Aug 2016


On 11 Aug 2016 Kevin Vande Vusse photographed a "funny-looking" Pectoral Sandpiper at the Muskegon Wastewater System and posted the image to the Facebook ID page. After several back-and-forths it was realized that he had discovered Michigan's 1st Sharp-tailed Sandpiper (Calidris acuminata). This "Siberian Pectoral Sandpiper" is a vagrant to North America and typically only seen in the Aleutians, Alaska, Hawaiian Islands, and Pacific Coast. To have one appear mid-continent is somewhat astounding. But sure enough, it was here, and birders from all over the midwest started flocking to Muskegon, MI to see the bird.

Robin and I took a day trip and drove 3 hours to Muskegon to look for the bird. Skies were mainly cloudy with high humidity, winds and brief rain showers. We arrived at about 1:30 pm and joined a dozen other birders trying to find the bird, which had disappeared for the previous 30 minutes in the weedy washout of the mid aeration ponds along the NW side of the Wastewater System.  Within 5 minutes we were able to relocate the bird among several Pectoral Sandpipers, Least Sandpipers, Semipalmated Plovers, and Killdeer.

This was not a cooperative bird, at all. No sooner would someone see it the Sharp-tailed Sandpiper would disappear back behind the vegetation patch, or among several of the Pectorals.  I managed to get some brief video captures despite the wind, rain, and distance (>300 ft). Lucky for me that I did, as my digiscoping photos failed to show the key identification marks of the bird, even at full magnification of the scope.

I used a Zeiss 85T*Fl Diascope Spotting Scope w/ a 20-75X Zoom Eyepiece, Sony Alpha a6300 Mirrorless Camera with a Sigma 30mm f/2.8 lens, and Digidapter™. At 75X magnification the equivalent focal length was ~2250 mm. However, when I videotaped the bird using 4K imaging the EFL doubled to ~5500 mm. This was enough to grab some sharp stills and see the characteristic identifiers of the bird, which appears (almost) identical to the Pectoral Sandpipers that are common here.

Take a look at the Pectoral Sandpiper (C. melanomas)  at left. Note the yellow legs, two-toned yellowish-gray bill, and distinct "bib" that stops abruptly at the chest and is bordered by an all-white belly, flanks and underside. The bib is finely-streaked and a white supercillium is visible above the eye. Its reddish-brown cheek patch is similar in color to its reddish-brown cap. White-fringed feathers on the back suggest that this is a juvenile bird that shows just a hint of a buffy wash on the breast.




This is a worn adult Pectoral Sandpiper foraging below the water. Note the uniform gray-brown feather coloration on back and neck.


The Sharp-tailed Sandpiper appears similar in size and shape, with a slightly shorter neck, shorter gray-black bill, and flatter head (Hayman, Marchant, Prater, 1986). Note the distinct "chevrons" along the side that extend below the undersides of the tails.





From this image you can see that the distinct bib of the Pectoral Sandpiper is absent. Instead, the chevrons grow in size as the bib is extended well onto the lower belly.

I had a difficult time seeing the distinct reddish cap on this bird. It could have been lighting, or the wind, or the distance, but the cap did appear darker relative to the Pectoral Sandpipers, but certainly not a distinguishing mark.



These images show the back side of the bird, which has brown-black feathers with cinnamon fringes. Nape, neck and cap all seem continuous in color.

If approved, this will be Michigan's 1st State Record of the species. Congratulations, Kevin on a great find!


Epilogue: Over 40 birders tried and failed to find the Sharp-tailed Sandpiper on Sunday, and apparently it hasn't been refound. Today (17 Aug 2016), an eBird report of a Sharp-tailed Sandpiper was posted from a fish hatchery in Arkansas! Same bird???? Michael Linz sent me an e-mail w/ pics of his bird in Central Arkansas. Congratulations, Mike!

References:

Hayman, P., Marchant, J., Prater, T., 1986, Shorebirds, an Identification Guide, Houghton Mifflin Company, Boston.

O'Brien, M., Crossley, R., Karlson, K., 2006, The Shorebird Guide, Houghton Mifflin Company, Boston.




1 comment:

the dude said...

Looks the adult I found two days later in central Arkansas. link here...

http://goo.gl/K0tj9f