Date: Tue, 22 Feb 2000 16:02:10 -0500 Reply-To: Maryland Birds & Birding Sender: Maryland Birds & Birding From: "Rob (Robert) Hilton" Subject: Re: Ruddy Shelduck In-Reply-To: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" For what it's worth, there are three Ruddy Shelducks reported from Ambler Reservoir, Ambler, Montgomery County, Pennsylvania: one male and two females. They were reported there yesterday. A recent article in British Birds (the May 1999 issue with the Ruddy Shelduck on the cover) made a case for natural British occurrence in 1994. An irruption in Fenno-Scandia coincided with the occurrence of flocks in Britain in the summer 1994. The Greenland birds were the westernmost individuals of a massive irruption in 1892, over a hundred years before. Best, Rob Hilton robert@csa.com At 03:32 PM 2/22/00 EST, you wrote: >From: "Phil Davis" , on 2/20/2000 10:14 PM: >At 03:02 PM 02/20/2000 -0500, Bill Teetz wrote: >(SNIP) >>I am rather new to listing, etc., but I have a question that some may >>consider off topic. Why is the Tufted Duck considered a sighting and the >>Ruddy Shelduck that some have seen at Hains Point thought to be an escapee >>since both are listed as Eurasian Species (at least in my Peterson's?) > > >Bill - > >This is a good question and this will probably generate a good deal of >follow-on discussion. > >First compare the ranges of the two ducks and patterns of vagrancy ... > >Tufted Ducks (_Aythya fuligula_) breed from Iceland east through >Scandinavia and Siberia (Russia) and as far east as the Commander Islands >(about 230 miles from Attu, Alaska). They migrate regularly into southern >Alaska. They also migrate irregularly down the Pacific Coast as far as >southern California and rarely inland into the states. In our hemisphere >in the winter, they are found in Greenland, along the New England and >Mid-Atlantic coasts, and in Bermuda. Inland, records come from the Great >Lakes and southern Canada. In the western hemisphere, they are found in >migration in Southern Africa, the Indian Ocean, and Micronesia. They, >therefore, seem to be quite cosmopolitan and records in the mid-Atlantic >are certainly not unexpected. Some sighting could always be escapes from >private waterfowl collections, and any signs of captivity (bands, clipped >toes, certain behaviors, etc.) would certainly be considered by local >records committees. > >Ruddy Shelducks ( _Tadorna ferruginea_), on the other hand, have a more >limited breeding range ... from southeastern Europe eastward to Turkey, >central Asia, to Mongolia. They also have a more compressed range of >migration, staying pretty much in the same longitudes ... northern Africa, >western Mediterranean, Arabian Gulf, Turkey, India/Pakistan, and to eastern >China. > >Now, the "analysis" ... > >In general, longer distance migrants (such as Tufted Ducks) tend to be >found "out of range" and become vagrants more often. > >The AOU, from whom we rely on for our taxonomy standards, recognizes the >Tufted Duck on the AOU Check-list, while the Ruddy Shelduck is contained in >"Appendix 1" of the Check-list, meaning there are North American records, >but the "natural occurrence ... of the species is disputed". While there >are sightings of these ducks in North America, the AOU presumes they are >escapes. The only accepted "natural" records of Ruddy Shelducks in our >hemisphere are from western Greenland. > >I think that all of these factors go into the general thinking that the >Tufted Duck is "probably" (at least from a percentage standpoint) a natural >vagrant, while the Ruddy Shelduck is likely an escapee. > >I think we should keep track of these Shelduck sightings, since the AOU >does reference such reports in its Check-list. > >Hope this helps ... > >Phil ======================================================================= To leave the MDOsprey list, send e-mail to listserv@home.ease.lsoft.com with the following message in line 1: signoff mdosprey ======================================================================= =========================================================================