Hi Greg/All,
Very observant! It is not 50-50, at least for White-winged Crossbill. Info from the Birds of North America White-winged Crossbill account: "Lower mandible crosses to right approximately 3 times more often than to left (Benkman 1988c <http://bna.birds.cornell.edu/bna/species/027/articles/biblio/bib008> )." Here is the info from the Birds of North American Red Crossbill account: "Lower mandible crosses to right as often as to left." Joan Collins Long Lake, NY From: bounce-74921622-13418...@list.cornell.edu [mailto:bounce-74921622-13418...@list.cornell.edu] On Behalf Of greg prelich Sent: Thursday, February 21, 2013 9:19 AM To: NYSBIRDS-L@cornell.edu Subject: [nysbirds-l] Crossbill question I've been looking at some photos I took recently of Crossbills and noticed that on one bird the upper mandible crosses over the right side of the lower mandible and on another bird it crosses on the left. Does anybody out there know if there is a preference either way, or is it a 50% proposition? Greg Prelich New Rochelle -- NYSbirds-L List Info: <http://www.northeastbirding.com/NYSbirdsWELCOME> Welcome and Basics <http://www.northeastbirding.com/NYSbirdsRULES> Rules and Information <http://www.northeastbirding.com/NYSbirdsSubscribeConfigurationLeave.htm> Subscribe, Configuration and Leave Archives: The Mail Archive <http://www.mail-archive.com/nysbirds-l@cornell.edu/maillist.html> <http://www.surfbirds.com/birdingmail/Group/NYSBirds-L> Surfbirds BirdingOnThe.Net <http://birdingonthe.net/mailinglists/NYSB.html> Please submit your observations to <http://ebird.org/content/ebird/> eBird! -- -- NYSbirds-L List Info: http://www.NortheastBirding.com/NYSbirdsWELCOME http://www.NortheastBirding.com/NYSbirdsRULES http://www.NortheastBirding.com/NYSbirdsSubscribeConfigurationLeave.htm ARCHIVES: 1) http://www.mail-archive.com/nysbirds-l@cornell.edu/maillist.html 2) http://www.surfbirds.com/birdingmail/Group/NYSBirds-L 3) http://birdingonthe.net/mailinglists/NYSB.html Please submit your observations to eBird: http://ebird.org/content/ebird/ --
