Not to be left out, I also visited the lake with my wife, 
Frances.  Here are some pictures of the goose in question. 
We also came to the conclusion that it was some kind of 
hybrid, but not sure exactly what.  My photos are an 
excellent match for the first picture on the web page Robert 
Ostrowski provided (very useful!): Greylag X Canada.

Pictures here:

    http://www.astro.umd.edu/~dcr/xfer/MysteryGoose/

Full report for the visit:

Report Details
Location name: Greenbelt Lake
Observation date: 2/2/06
Duration: 1 hour(s) 40 minute(s)
# of people in birding party: 2
Are you reporting all the species you identified? Yes
Total # of species: 26
Observation type: Stationary Count
Start time: 12:30 PM
Distance covered: N/A
Area covered: N/A
Weather had a negative effect on my ability to collect 
birding information: No

Checklist diary notes:
A visit to the lake to look for the report Greater 
White-fronted Goose. Instead we found a strange goose that 
may be some kind of domestic hybrid: noticeably larger, 
longer and thicker necked than a Canada Goose, with a 
flattened head, large pink bill with black nail and white 
base, pale cheek patch on dark face and neck, bold pale eye 
ring, dark upperparts over pale underparts (with a wavy 
horizontal margin, not flat like Canada Goose), white 
undertail, and yellowish/pinking legs and feet. I couldn't 
find a convincing match with any domestic species in my 
guides. Weather: warm and sunny, with a light breeze. There 
may have been a second creeper.



Species Details
Species Name Number Reported
Canada Goose 40
Mallard 40
Ring-necked Duck 2
Hooded Merganser 6
Ruddy Duck 3
Great Blue Heron 1
Turkey Vulture 1
Ring-billed Gull 20
Mourning Dove 5
Belted Kingfisher 1
Red-bellied Woodpecker 1
Downy Woodpecker 1
Pileated Woodpecker 1
Blue Jay 3
Fish Crow 6
Carolina Chickadee 3
Tufted Titmouse 2
Brown Creeper 1
Carolina Wren 2
Northern Mockingbird 1
Eastern Towhee 1
Song Sparrow 2
White-throated Sparrow 10
House Finch 2
American Goldfinch 10
House Sparrow 1

-- 
Derek C. Richardson, Ph.D. (CANTAB) ________
Astronomy, U Maryland, College Park MD 20742
Tel: Office 301-405-8786 Fax 301-314-9067 __
Home page: http://www.astro.umd.edu/~dcr/ __