[CT Birds] Winter High Species Totals (Preliminary CBC Results)

[Linda & Steve Broker]

 From Steve Broker (Cheshire):

Several recent listserv posts have called attention to high numbers  
of bird species including Yellow-bellied Sapsucker, Blue Jay,  
American Robin, and White-throated Sparrow.  While cold fronts and  
snowstorms may account for the current high numbers of some species,  
it may be useful to look at Christmas Bird Count data for 2009-2010  
for further evidence of this winter’s high and low species totals.   
I’ll post comments on this year’s CBC high species totals here and  
will follow with a post on low species totals.

Each year, Connecticut conducts 18 Christmas Bird Counts (6 northern,  
5 mid-state, and 7 coastal), several of which cross over into New  
York and Rhode Island.  Ten of these counts now have posted results  
on National Audubon Society’s BirdSource website, and two additional  
count compilers have sent me their results.  With 6 count circles yet  
to report their results, the following generalizations are  
tentative.  They are based on a comparison of this year’s current  
species totals with the last 30 years of CBC data.

A dozen or so bird species were recorded during the 2009-2010 CBC  
season in high or record high numbers.  They are:  Brant; Wood Duck;  
Bufflehead; Northern Gannet; Merlin; Peregrine Falcon; Yellow-bellied  
Sapsucker; American Robin; Savannah Sparrow; White-throated Sparrow;  
Dark-eyed Junco; Red-winged Blackbird; Common Grackle.

Brant has been counted in much higher numbers over the last decade  
than it had been in the twenty previous years.  Fourteen Merlin  
reported are well short of the record high of 27 in 2005-06, and 17  
Peregrine Falcons approach the record high of 20 in 2008-09.  Merlin  
and Peregrine numbers have been on steady increase for the last 15  
years or so.  The Yellow-bellied Sapsucker total in submitted CBC  
results stands at 120, continuing a 12-year trend in increasing  
numbers of this woodpecker species, greatly accelerated in the last  
several years.  The record high is 196 in 2007-08, with last year’s  
total being 129.  American Robins have achieved their second highest  
total in 30 years, with 27,959 reported thus far.  However, the  
record CBC total for robins is 40,798 in 2001-02.  As noted in  
“Connecticut Birds By the Season, by Greg Hanisek (The Connecticut  
Warbler, January 2005; also available from COA as a reprint), “[a]  
few species that are common to abundant breeders become generally  
less common in winter, but can occur in large flocks at that season.   
Most notable are American Robin, Red-winged Blackbird, Common  
Grackle, and Brown-headed Cowbird.”

The 10,158 White-throated Sparrows recorded on 12 CBCs this year  
already constitute a 30-year record high total for Connecticut CBCs,  
surpassing the 9,989 counted on all 18 counts in 2007-08.  Juncos  
have appeared to be abundant this winter, with 12,892 reported on  
CBCs to date, but there are six other years in the last 30 in which  
juncos were counted in higher numbers.  The record total is 16,571 in  
1998-99.  Finally, two of the species of flocking birds mentioned  
above, Red-winged Blackbird and Common Grackle, were in high numbers  
this early winter.  The 11,425 blackbirds are the second highest  
total in 30 years, still well below the 26,298 of 1996-97.  The  
32,207 Common Grackles also are second highest, trailing 42,133  
counted in the same 1996-97 CBC season.  Brown-headed Cowbird numbers  
appear to be below average this winter.

Interestingly, the Blue Jay numbers submitted to date for this year’s  
statewide CBC also are average or below average.  The 3,782 jays  
reported in the previous (2008-09) CBC were the lowest total in 26  
years.  This is a species that does not exhibit quite such extreme  
swings in flock sizes as do robins, blackbirds, grackles, and cowbirds.