LISLE ARBORETUM CHRISTMAS BIRD COUNT
Special Notes for 2008


"Code 4" birds that have been moved to "Code 3". You'll be interested to know that a number of previously "Code 4" birds have been moved up to "Code 3". This means you no longer need to document these birds. This list includes Northern Shoveler, Northern Pintail, Ring-necked Duck, Bufflehead, Hooded Merganser, Red-breatsed Merganser, Pied-billed Grebe, Killdeer, Northern Saw-whet Owl, Eastern Towhee, Lapland Longspur, Snow Bunting, and Common Redpoll. The tally sheets have been updated to reflect these changes.

Participants in the U.S. pre-paying online for their Christmas Bird Counts can participate in four or more CBCs for a flat $20.00 fee. See the Audubon Christmas Bird Count web site for details, and please contact the compiler (Geoff Williamson) at lislecbc@chicagobirder.org if this affects your payment of the Lisle-Arboretum CBC fee.

Trumpeter Swans: Trumpeter Swans have been present in the Palos area, but we always have a chance to get Tundra Swans on the count, too. Don't make assumptions on the species identity of any swans that you see! All swans are "Code 4" and require documentation to be included in the count tally. Some web resources for swan identification that you may find helpful are David Sibley's swan identification page and Kevin McGowan's Swan ID in Upstate New York page.

Cackling Goose: As requested for the last few years, please be careful with your identifications of Cackling Goose! You will need to complete documentation on any Cackling Geese you report. Cackling Geese are smaller than Canada Geese. Make special note of the bill size, shape of the head, size in comparison to nearby birds, relative coloration of the breast, whether or not the black "neck stocking" is separated from the breast by a white collar or pale crescent, the voice, and length of the wings.

Be aware that Canada Geese can look small and short necked in certain postures. Cackling Geese that you can be sure of will be about the size of a Ross's Goose. Note on the individual pictured here (taken on Montrose Beach, Chicago, Cook County on 7 October 2004) that the bill is very stubby and that the forehead is steep. This bird shows a pale frontal crescent (Michael Retter notes that he sees this on about 25% - 30% of the Richardson's Geese -- the subspecies of Cackling Goose most common in Illinois -- that he sees). Note also on this individual that the wingtips extend past the end of the tail. This may be a helpful clue.

Here are some web pages with information about Cackling Goose identification.

Other changes in the bird codes. This year I reviewed the status of all the birds we record on the count, as reflect in the "Code" of the bird. The working definitions for Code 1, Code 2, Code 3, and Code 4 are now the following.

  • Code 1: birds seen in all six areas in all years.
  • Code 2: birds seen on average in at least three of the six areas in all years.
  • Code 3: birds seen in at least four of the last 15 years and at least six of the last 30 years.
  • Code 4: unusual species requiring documentation.

I applied the definitions for Code 1 and Code 2 using the last six years of count data, broken down by area. This has resulted in the following changes.

Species promoted from Code 2 to Code 1: Ring-billed Gull, Red-bellied Woodpecker, Hairy Woodpecker, Blue Jay, White-breasted Nuthatch, American Robin, Cedar Waxwing, Song Sparrow, White-throated Sparrow.

Species promoted from Code 3 to Code 2: Great Blue Heron, Sharp-shinned Hawk, Carolina Wren, Eastern Bluebird, Hermit Thrush, Yellow-rumped Warbler, Fox Sparrow.

Species promoted from Code 3 to Code 1: Cooper's Hawk.

Species demoted from Code 2 to Code 3: Rough-legged Hawk, Red-headed Woodpecker, Red-winged Blackbird, Common Grackle, Purple Finch, Pine Siskin.

Last modified on 7 January 2008
by Geoffrey A. Williamson