ajohn

It is a juvenile Whimbrel.

Young shorebirds typically take some time to fully grow the bill. This can often be noticeable with juvenile whimbrels, curlews and godwits during southward migration. Young curlews and whimbrels also have straighter bills than adults, which gradually develop the typical downward curve as they mature.
Your bird appears to be a juvenile, which would explain the relatively short and straight bill. Your photo illustrates this well.