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Sussex Christmas Bird Count Review

by Brian Elliot

    The questions started after seeing the results of the 1997 and 1998 counts side by side. I noticed that some birds had increased 4 fold, (Ravens jumped from 205 to 878), others dropped dramatically, (European Starlings dropped from 1087 to 660). I wondered if these changes were significant trends or if they were isolated occurrences. The search for answers was on.

    Thanks to Gart Bishop, Jim Brown and David Christie I was able to locate Sussex Christmas Bird Count records for 26 years - 1971 to 1998, (with the exception of 1972 and 1973). Now I've got lots of data but how can I make sense of it with sheets scattered everywhere. I can't, so I enlist the help of Irene to read the count numbers as I entered it them on a spreadsheet on our computer.

    Patterns start to emerge. Some species are seen every year, others only one or twice in the 26 years. The following chart shows the top of the frequency list as well as the average number of sightings per year. Although the numbers of Woodpeckers and Grouse are lower, they do get spotted most years. Three species that have higher average sighting numbers the years they are seen, but are not seen as frequently, if that makes sense ..., are Snow Bunting, (21 years, 150 ave. per year), American Goldfinch, (22 years, 119 ave. per year), and Mourning Dove, (20 years, 87 ave. per year).

Species	# of years spotted	Average per year
House Sparrow	26	217
European Starling	26	471
Rock Dove	26	428
Bk. Capped Chickadee	25	177
Common Raven	25	147
Blue Jay	25	93
Hairy Woodpecker	25	8
Downy Woodpecker	25	10
American Crow	24	165
Evening Grosbeak	24	184
Ruffed Grouse	24	6
Dark-eyed Junco	24	54

    Those seen only once or twice over the 26 years are :

Northern Harrier	2
Common Snipe	2
Eastern Meadowlark	2
Hoary Redpoll	2
American Kestral	2
Eastern Towhee	1
Hermit Thrush	1
Logger-head Shrike	1
Merlin	1
White-winged Scoter	1
Cedar Waxwing	1
Black-backed(3toed)Wood	1
Common Goldeneye	1
Barred Owl	1
(N) Three-toed Woodpecker	1
Red-bellied Woodpecker	1
Ring-billed Gull	1
Fox Sparrow	1
Field Sparrow ?	1
Baltimore Oriole	1
Monk Parakeet	1
White-crown Sparrow	1
Broad-winged Hawk	1
Red-winged Crossbill	1
Black Scoter	1
Northern Pintail	1
Golden Eagle	1
Gray Partridge	1
Hooded Merganser	1
European Goldfinch	1
Red-breasted Merganser	1
Cooper's Hawk	1

    It seems the frequency and numbers make some sense. Those species in the first list are those we expect to see in the Sussex area in the winter months. Those in the second are the rare treats we all look forward to each year as stragglers stay a little late, or weather patterns bring unusual visitors. But look at the numbers more closely and other questions come to mind.

    Consider the total number of birds counted each year. That number ranges from 654, (in 1982), to 8,746, (in 1995), with an average of 2,638. The number of species counted ranges from 11, (in 1975), to 51, (in 1994 and 1995), with an average of 32.