See Mackenzie, John P.S. "Birds of the World: Wading Birds" (p.119) 1997
Key Porter Books. ISBN 1-55013-279-2 (hard)This is a pictorial book.

Photo is a Long-billed curlew in flight, backlit by the sun. This is much
more contrast than one would normally see. Maybe this would be helpful to
your inquiry.

Other option is a marbled godwit.