Hi Tom, Peter Jordan at the U Dept of FWCB forwarded your message.
I too find the band sighting and data enigmatic but for reasons other then your's. First I'll address your concerns then present mine. As you and other bird enthusiasts know, Canada goose taxonomy is also enigmatic with--depending on the authority--8 to more than 40 subspecies. Recently DNA analysis suggests that there may be two species (large and small) and large and small subspecies for each! However, the occurrence of a "smaller" goose banded as a gosling in Illinios can be explained without referring to confusing subspecific details. Geese attain about 90% of their adult morphology during the 8-10 week pre-fleging period. While not well documented, warm dry summers with poor grazing or rearing habitat with too many geese competing for limited forage results in "smaller" geese compared to those reared in cool wet summers. Flightless goslings with injuries are also often smaller then their cohorts and while we assume that most die (per BBL policy, I've alway released them unbanded) prior to fledging some likely survive and remain small "runts" throughout life. It's presence in Minnesota in winter is not unusual. In addition to the normal spring and fall migrations, geese have a third migration call the molt migration. Sexually immature geese, many unsuccessful breeding pairs, and in some year up to 50% of the successful breeding pairs (they abandon their young) leave the breeding area and fly north sometime from mid-May through June. The Minnesota molt migrants typically travel 800+ km north to the shores of subarctic rivers and lakes, or Hudson Bay. There they molt and regrow their flight feathers and fly south in fall. Research on Canada goose molt migrants show that Twin Cities geese are spread along the shore of Hudson Bay from Norway House to the Manitoba-Nunavat border with some found further north on the Thelon River. When Bob Fashingbauer did his MS thesis work on Canada goose molt migrants at Grand Marais, he retrapped 24 birds banded elsewhere. Most were from Wisconsin and Illinios. Bob found that 90% of the geese he neckbanded had left Grand Marais by mid-October. This means some could have stayed in late fall or early winter. Canada geese are also weak fall-spring migrants and many remain in northern areas during mild falls and winters. While this winter has been cold since mid-January, it was relatively mild and snowless until then. Thus the small goose was most likely a molt migrant from Illinios that stayed on the North Shore because of the mild fall. What puzzles me is the fact that you could read a 20-old legband. The aluminium legbands used for geese are relatively soft, wear quickly, and are frequently lost within 10 years. Over the past 30 years, I've encountered only two banded geese over 20 years of age and both worn color-coded plexiglass bands. One of these, a female breeding at 20 and 21 years, retained an unreadable aluminium legband that slipped easily into the plexiglass band below it. The oldest readable aluminium band I've encountered was on an 18-year female. I would appreciate hearing about the circumstance under which you read the band. Thanks, Jim Cooper -- Dr. Jim Cooper Professor Emeritus Department of Fisheries, Wildlife, and Conservation Biology University of Minnesota 1980 Folwell Ave. St. Paul, MN 55108 Voice: 651-644-6206 Fax: 612-625-5299 on 2/23/05 16:35, Peter A Jordan at [email protected] wrote: > > ----- Original Message ----- > From: "Tom Auer" <[email protected]> > To: <[email protected]> > Sent: Tuesday, February 22, 2005 4:42 PM > Subject: [mou] Banded Canada Goose Recovery Data > > >> I submitted data to the Bird Banding Lab in Maryland for a banded >> Canada Goose that I (and others) saw in Two Harbors on 1/1/8/2005. >> Today, I received a certificate from the lab, reporting the initial >> banding data. This bird was 20 years old!!!!! >> >> Banded: 06/27/1985 >> Age: Was too young to fly when banded in 1985. >> Location: Ledford, IL (just east of Carbondale, IL) >> Bander: Illinois DNR >> Recovered: Two Harbors, MN >> Date: 01/18/2005 >> >> This is a very enigmatic record in my opinion. First of this was a >> "smaller" goose, I'm not calling this bird a Cackler by any stretch, >> but this was one of the smaller Canada Geese, which was fully aged at >> 20 years. Second, what is it doing wintering NORTH of where it was >> born??? Very interesting. >> >> Tom Auer, >> Duluth >> -- >> www.d.umn.edu/~auer0009 >> _______________________________________________ >> mou-net mailing list >> [email protected] >> http://cbs.umn.edu/mailman/listinfo/mou-net >> >
