john@nmtsun.nmt.edu (John Shipman) (12/01/88)
David Mostardi (mostardi@ux1.lbl.gov) writes: > ...on Sunday I am going to Stockton to search for a bird > called a Tundra swan, but said swan is not in my N. Amer. field > guide. Your field guide will probably call this bird a Whistling Swan. This species was lumped with the far-north Bewick's Swan recently, and Tundra Swan is the name for the new, combined form. If you got this information off the N. Cal. Rare Bird Alert, the bird is probably correctly identified. However, if you see a swan that hasn't been worked over by the experts, watch out for Trumpeter Swan! If you see *any* swan in the west, take pictures if possible, and also note carefully the exact configuration of the bill and head. The characters that separate Tundra from Trumpeter swans involve the extent and position of light colors on the bill and also the extent of feathering near where the base of the upper mandible joins the forehead. Sketch the entire head if possible. Don't rely on field guides to make this distinction; even the new National Geographic guide has some problems here. Submit your records to experts, and even then they may not be able to tell. -- John Shipman/Zoological Data Processing/Socorro, New Mexico USENET: ucbvax!unmvax!nmtsun!john CSNET: john@nmtsun.nmt.edu ``A lesson from past over-machined societies...the devices themselves condition the users to employ each other the way they employ machines.'' --Frank Herbert