"Pine siskins can temporarily store seeds totaling as much as 20% of their body mass in an enlarged part of their esophagus called a crop. They often fill their crop with seeds prior to nightfall, as the energy in this amount of food can sustain them through 5-6 hours of sub-zero temperatures." Naturally Curious Day by Day -Mary Holland Sar P.S. I've read the same thing about other species having these "elastic" crops including redpolls, doves, ruffed grouse, some raptors etc.
-- Cayugabirds-L List Info: Visit: http://LISTS.cornell.edu for more information Posting Address: [email protected] Archives: The Mail Archive: https://www.mail-archive.com/[email protected]/maillist.html Sightings: Please submit your observations to eBird at http://www.ebird.org. --
