[CT Birds] Historical data to think about on a rainy day

Christopher Loscalzo closcalz at optonline.net
Sun Jan 10 12:20:32 EST 2016

I was organizing my papers for the New Haven Christmas Bird Count today and
I came across a review of the data from 1901-1974 written by none other than
Fred Sibley.  He talked about the increase in the number of species being
recorded in the latter years, primarily as a result of increased
participation and coverage. He also listed the high counts for the species
being seen in that time period.  A few things jumped out at me as I looked
through the data.  There are a number of species that have gone through a
precipitous decline in the last 40-50 years.  Twelve in particular that have
had a > 90% decrease in their wintering populations are:

American Black Duck (5,000 seen in 1973)

Canvasback (3,000 seen in 1972)

Greater Scaup (13,000 seen in 1969)

White-winged Scoter (2,000 seen in 1971)

American Kestrel (25 seen in 1974)

Ruffed Grouse (34 seen in 1969)

American Coot (930 seen in 1967)

Killdeer (101 seen in 1973)

Purple Sandpiper (115 seen in 1970)

Evening Grosbeak (484 seen in 1969)

American Tree Sparrow (984 seen in 1973)

Field Sparrow (194 seen in 1969)


Some species are being recorded now in greater numbers than that era, and
other species (e.g., Black Vulture and Common Raven) are here now and were
not present at all then.  


Habitat loss, climate change, pollution, and other factors have played a
role in these changes.  More are to come, no doubt.  


Let's hope we can all have a positive impact on bird populations in our area
and elsewhere.   


Best regards and good birding to all.

Chris Loscalzo,





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