Things got a bit tense for a moment when a Northern Harrier made a half-hearted swipe at the curlew and caused it to make itself small in the grass. The harrier then went after a pair of Upland Sandpipers that were closer to the runway where the Western Meadowlark was perched and singing.
After a few more pics I grabbed the scope and attempted to get a video of the bird for ID purposes. I watched it for several minutes foraging and eating large night crawlers in the stubble. I cranked the Zeiss 85T*FL Diascope and 20-75X Zoom eyepiece to full 75X magnification in order to get the bird large enough to view. With the Nikon 1 V3 and 10-30mm PD lens zoomed to 30mm, I was getting an EFL of 75x30x2.7 = 6075mm! Heat shimmer at this magnification and distance was intense, but did not interfere with me being able to verify the lack of head striping associated with Whimbrels, and to see the clean brown/white feather barring and dark-centered coverts that is more distinct than the softer brown back feathers of Whimbrel. Note also that this curlew has pale lores (area between eye and bill), as opposed to the dark lores that are part of the streaking that goes through the eye on Whimbrel. Head is finely streaked white and neck shows fine streaking. During the video you can even see some of the cinnamon coloration in the flanks and underwing when it fluffs up.
Images below are reference images of a Long-billed Curlew I photographed in Florida a few years ago. Compare with the Whimbrel images taken in similar lighting.