CBC Results from Fermilab

I always find it interesting to see how others have treated CBC data, especially how they have analyzed it for status and trends and how they present the results. In this example, Peter Kasper presents data from the Fermilab, located in Batavia, Illinois, about 45 miles west of Chicago, where Christmas Bird Counts have been conducted annually since 1976. Peter illustrates the 5-10 most numerous species by use of graphs and pie charts; summarizes data for each species by means of tables and graphs, as in this example for Canada Goose; and illustrates annual highlights. 

The 9th (1908) CBC

The following two paragraphs introducing the results of the 9^th (1908) CBC in Bird-Lore, particularly the last one, indicates that the concept of a well-defined “count circle” had not yet been work out, nor had any thought been given to the idea of multiple “parties” working in tandem. The CBC was still truly in its infancy:  

A correspondent asks how it is possible to state with accuracy the number of individuals of a species seen. Where the number is small, no difficulty should arise here, provided one’s route does not bring the same birds under observation more than once; but where birds are abundant, it is not expected that one can ascertain their exact numbers. But an estimate, however, conveys a much more definite idea than the terms, “Common,” “Abundant,” etc.     

            It is also asked whether, when censuses are signed by more than one person, the observers worked together, all seeing practically the same birds, or whether they worked independently of one another, the census being their combined records? We assume in cases of this kind that the observers are more or less closely associated; but in the future it would be well to have an understanding in regard to this matter, so that when observers take different routes, the results will not be combined in one census, when, in fact, two or more censuses have been made.—ED. [=Frank M. Chapman] [Source: Bird-Lore 11:30-31 (1909)]

Following are the results of the four counts reporting from Michigan in 1908:

Detroit, Mich., at Palmer Park.—Dec. 25; 10 A.M. to 12 M. Cloudy, misty, threatening snow; three inches of snow on ground; wind, north; about ten miles; temp., 33°. Junco, 4; Tree Sparrow, 3. Belle Isle Park.—Dec. 27. Conditions much the same as above, except wind blowing twenty miles. Herring Gull, 15; Red-headed Woodpecker, 1; Hairy Woodpecker, 1; Crow, 6; Blue Jay, 1; White-breasted Nuthatch, 4; Tufted Titmouse, 1; Chickadee, 1. Total, for two days, 10 species, 37 individuals [Careful readers will note that this is actually two counts, covering two distinct areas on two different days, masquerading as one].—JEFFERSON BUTLER.

            Kalamazoo, Mich.—Dec. 25; 11 A.M. to 1 P.M. Cloudy; light snow; ground partly bare; wind northwest, moderate; temp., 30°. Blue Jay, 2; Crow, 40; Lapland Longspur, 75; White-breasted Nuthatch, 1. Total, 4 species, 118 individuals.—WM. E. PRAEGER.

            Port Sanilac, Mich.—Dec. 28; 10.30 A.M. to 1 P.M. Bright sunshine; two to fourteen inches snow, crusted; wind west and light, changing to south and stronger; temp., 28° to 36°. Herring Gull,2; American Merganser, 7; Downy Woodpecker, 2; Crossbill (sp.), 10; Junco, 75; Song Sparrow, 4; Chickadee, 25. Total, 7 species, 125 individuals.—ETHEL B. CHASE, MRS. JOHN S. THOMSON, and HARRIET W. THOMSON.

            Benzonia, Benzie Co., Mich.—Dec. 28; 9 A.M. to 12 M. Snow slightly, increasing later; wind northwest, sno ten inches deep; temp. 28°. Herring Gull, flock of 48; Bob-white, flock of 10; Hairy Woodpecker, Downy Woodpecker, Blue Jay, Redpoll, White-breasted Nuthatch, Chickadee [Note that the compiler failed to indicate the number of individuals seen of the last six species, simply implying that they were present on the day of the count. Not knowing how many individuals of each species were seen, but confident that each species was seen on count day, it seems reasonable to record at least one individual of each species. Instead, the CBC database records them as count-week birds]. On the evening of December 27, I heard four Horned Owls.—ELIHU LINKLETTER.

CBC Trends in Berrien County (1962-2012)

The 8th (1907) CBC in Michigan

Michigan was represented in the 8^th (1907) CBC by a single count, as described below:  

Detroit (Belle Isle).—Dec. 25; 8.15 to 11 A.M. Cloudy and hazy; no snow on ground but covered with heavy frost; winter very light and from northeast; temp., 34°. Herring Gull, 3; Hairy Woodpecker, 8; Crow, 9; White-breasted Nuthatch, 26; Chickadee, 12; Brown Creeper, 1. Total, 6 species, 59 individuals.—JEFFERSON BUTLER. Source: Bird-Lore 10:36 (1908).