I have little to add and nothing to correct in Dave' nice summary. Crows in and around Ithaca usually choose among several modest roosts (500-5,000 crows). Some years the main Ithaca roost is hardly noticeable, and in others it's in your face. The crows typically stage on the Cornell and Ithaca Country Club golf courses before heading to the main roost. Exactly where the final roost is changes between and within seasons. I have not been downtown in the evening, and I do not know where the final roost is at this time.
Kevin J. McGowan, Ph.D. Instructor Home Study Course in Bird Biology Cornell Lab of Ornithology 159 Sapsucker Woods Road Ithaca, NY 14850 k...@cornell.edu<mailto:k...@cornell.edu> 607-254-2452 From: bounce-7531176-3493...@list.cornell.edu [mailto:bounce-7531176-3493...@list.cornell.edu] On Behalf Of Dave Nutter Sent: Thursday, December 16, 2010 7:27 AM To: cayugabirds-l@cornell.edu Subject: Re: [cayugabirds-l] Crows? Andrew, Crows are very social animals. They live in family groups during the breeding season, with a multi-year learning period, and young birds raised the previous year often help their parents to raise their younger siblings. In the non-breeding season crows gather into massive roosting congregations in the late afternoon. In recent years these roosts have been much more conspicuous to people as the birds have chosen urban areas with large trees. In the morning they commute to farm fields to search for waste corn or to dumps (or the Cornell food services composting facility) for waste food. Toward March and the onset of breeding season the roost breaks up and the birds return to their family territories. I think some local birds here retain residency in their territories during winter as well. Those winter roosts are amazing, just to consider all the biomass, and the area over which they must be feeding. Their socializing is noisy and active before and after their actual sleeping time and includes areas outside the actual roost. They are harmless, of course, but people whose knowledge of biology extends only to Alfred Hitchcock movies may be unnerved. And people whose possessions are underneath roost trees with hundreds of birds will be understandably unhappy with the birds' defecation. I like to watch the flocks' swirling flight. Kevin McGowan has been studying crows in this area for years, and I hope he will expand upon (and if necessary correct) this post. His project is responsible for the crows with various colored wing tags, each color representing a different year. Most crows are tagged in the nest before they are old enough to leave. Each bird's tags has a 2-digit code, and if you tell Kevin which bird you have seen when and where, he may return the favor with a brief life history of that individual. --Dave Nutter On Dec 15, 2010, at 07:05 PM, Andrew Roe <andrew.walker....@gmail.com> wrote: This is only my second winter in Ithaca (I'm a grad student, here from the southeast) so I don't really know how normal this is- but there seem to be an ENORMOUS number of crows around downtown Ithaca and Cornell- swirling at dusk, covering roofs, nearly toppling trees, blotting out the sun, etc. Can someone in the know let me know what's going on? Are these all birds passing through, or is there some sort of monumental attack on the Lab of O in the works? Thanks, Andrew -- Cayugabirds-L List Info: http://www.NortheastBirding.com/CayugabirdsWELCOME http://www.NortheastBirding.com/CayugabirdsRULES ARCHIVES: 1) http://www.mail-archive.com/cayugabirds-l@cornell.edu/maillist.html 2) http://birdingonthe.net/mailinglists/CAYU.html 3) http://www.surfbirds.com/birdingmail/Group/Cayugabirds Please submit your observations to eBird: http://ebird.org/content/ebird/ --
