No, Common Ravens have never been recorded having helpers. Pairs are intensely territorial and their offspring leave in their first summer.
American Crows are odd in being cooperative breeders. None of the other crows or raven are, except for a few populations of the Carrion Crow (in Spain). Many of the New World jays are cooperative breeders, as are some of the Asian green and blue "magpies" (but not THE magpie). Kevin From: Richard Guthrie [mailto:[email protected]] Sent: Friday, April 27, 2012 5:44 AM To: Kevin J. McGowan; 'Jack Rothman'; NYSBIRDS-L Subject: RE: [nysbirds-l] Successful Raven Fledge in Bronx Good Morning; As with other corvids, do ravens sometimes find extended family (or outsiders?) joining a nesting pair to "help" during the fledgling nest stages? If so, the third bird may be a visiting "parent". Rich Guthrie New Baltimore, The Greening County New York [email protected]<mailto:[email protected]> From: [email protected]<mailto:[email protected]> [mailto:[email protected]] On Behalf Of Kevin J. McGowan Sent: Wednesday, April 25, 2012 6:11 PM To: Jack Rothman; NYSBIRDS-L Subject: RE: [nysbirds-l] Successful Raven Fledge in Bronx Very cool observations. But, the timing doesn't sound quite right. Richard wrote that he thought the nest was compete around 24 February. If we assume that the clutch was being laid then, an incubation start on 28 Feb is reasonable, and pretty close to the very few New York raven pairs for which I've seen data. An incubation period of about 19 days would put hatch at 18 March, and chicks should be 38 days old today. That's about a week shy of a normal fledging, and about a month or two before a fledgling would look like a raven or be able to fly overhead. They should be awkward and have tails only half-grown at this point. Did the third raven have a full tail? IF so, I wonder if it was another adult checking out the pair. Keep watching! Best, Kevin From: [email protected]<mailto:[email protected]> [mailto:[email protected]]<mailto:[mailto:[email protected]]> On Behalf Of Jack Rothman Sent: Wednesday, April 25, 2012 5:52 PM To: NYSBIRDS-L Subject: [nysbirds-l] Successful Raven Fledge in Bronx I went over to check on the raven's nest discovered by Richard Aracil today at 4PM today and first saw no activity at the nest. I scanned the surrounding areas looking for the birds after standing around craning my neck, watching the enclosure that houses the water tank, for close to an hour. When I looked up again, I saw three ravens fly over the building that houses the nest. I was not able to get a photo but I definitely saw 3 ravens. I tried to locate the birds but they probably landed on one of the areas on the building that was not visible. The buildings in Coop City are quite high and the angle from the ground to the top are sharp, so visibility on the top is difficult. I believe this fledge is a record for the Bronx. The building is located at 120 Elgar Place, building 34 Jack Rothman Bronx, NY www.cityislandbirds.com<http://www.cityislandbirds.com> -- NYSbirds-L List Info: Welcome and Basics<http://www.northeastbirding.com/NYSbirdsWELCOME> Rules and Information<http://www.northeastbirding.com/NYSbirdsRULES> Subscribe, Configuration and Leave<http://www.northeastbirding.com/NYSbirdsSubscribeConfigurationLeave.htm> Archives: The Mail Archive<http://www.mail-archive.com/[email protected]/maillist.html> Surfbirds<http://www.surfbirds.com/birdingmail/Group/NYSBirds-L> BirdingOnThe.Net<http://birdingonthe.net/mailinglists/NYSB.html> Please submit your observations to eBird<http://ebird.org/content/ebird/>! -- -- NYSbirds-L List Info: Welcome and Basics<http://www.northeastbirding.com/NYSbirdsWELCOME> Rules and Information<http://www.northeastbirding.com/NYSbirdsRULES> Subscribe, Configuration and Leave<http://www.northeastbirding.com/NYSbirdsSubscribeConfigurationLeave.htm> Archives: The Mail Archive<http://www.mail-archive.com/[email protected]/maillist.html> Surfbirds<http://www.surfbirds.com/birdingmail/Group/NYSBirds-L> BirdingOnThe.Net<http://birdingonthe.net/mailinglists/NYSB.html> Please submit your observations to eBird<http://ebird.org/content/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/[email protected]/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/ --
