If you Google "shorebirds" + "failed breeders" you'll get a lot of hits, and you'll see the word 'presumed' again and again. The Ontario Field Ornithologists website offers a more cautious assessment:
"Failed Breeders: Most adult shorebirds do not stay long on the breeding grounds after nest failure or loss of chicks. Some very early or earlier than normal first migrants in full alternate (breeding) plumage may be failed breeders. However, adults of most species appear at the same time every year suggesting that the “failed breeders” explanation is questionable in many cases." http://www.ofo.ca/reportsandarticles/southboundshorebirds.php When deciding how early is early enough in the Cayuga Basin to risk floating the "failed breeder" explanation, Steve Kelling's shorebird bar chart might be useful: http://www.birds.cornell.edu/cayugabirdclub/firstrecords/shorebirds.htm -Geo Geo Kloppel Bowmaker & Restorer 227 Tupper Road Spencer NY 14883 607 564 7026 g...@cornell.edu geoklop...@gmail.com -- Cayugabirds-L List Info: http://www.NortheastBirding.com/CayugabirdsWELCOME http://www.NortheastBirding.com/CayugabirdsRULES http://www.NortheastBirding.com/CayugabirdsSubscribeConfigurationLeave.htm ARCHIVES: 1) http://www.mail-archive.com/cayugabirds-l@cornell.edu/maillist.html 2) http://www.surfbirds.com/birdingmail/Group/Cayugabirds 3) http://birdingonthe.net/mailinglists/CAYU.html Please submit your observations to eBird: http://ebird.org/content/ebird/ --