Biology Reference
In-Depth Information
and state birding organizations. Depending on how rare the sighting is, you may need all
those notes you took!
Q I've read about places in the United States where more than a hundred thousand
hawks fly past in a single day, and about a place in Mexico where more than a milli-
on birds may fly past in a single day. How is it possible to count so many?
A
I can give you an example of a count I witnessed on September 15, 2003, at Hawk
RidgeBirdObservatoryinDuluth,Minnesota,whenatotalof102,329hawkswerecoun-
ted. Fully 101,698 of them were Broad-winged Hawks. There were also 445 Sharp-
shinned Hawks and 83 American Kestrels. No more than 35 individuals were counted of
any other species. How did they count them all and keep the species straight?
That day there were several counters, each in charge of one area of the sky, and each
counterhadavolunteerassistantrecordingbirds.HawkRidgeisabluffamilefromLake
Superior.Onecounterwasinchargeofcountingbirdsflyingabovethelake,withskyand
water in the background. Another counted birds below the ridge, with houses and trees in
the background. One took the birds flying overhead, and one took the birds along the far
sideoftheridge,oppositethelake.Thebirdsweren'tcrossingpathsbecausetheywereall
moving parallel to the lake, but other experienced birders at the count station were keep-
ing track of the overall movement patterns to alert the counters if there were any shifting
paths so birds wouldn't be counted twice.
The counters counted Broad-winged Hawks, sometimes by tens and sometimes even
by hundreds, and then called out the final number for each
kettle
(a swirling mass of
hawks numbering anywhere from about five to many thousands) to the assistant who
wrote down the number. Meanwhile, as Sharp-shinned Hawks passed by, the counters
clickedthemonamechanicalclicker.Everyhourthatnumberwasrecordedandtheclick-
erresettozero.Asthecounterwascountingthesetwospecies,ifabirdofanotherspecies
went by, the counter called it out for the assistant to record individually.
That was, as of the end of the 2008 hawk-counting season, the biggest day ever
at Hawk Ridge. The second largest flight was recorded on September 18, 1993, when
49,548 were counted. Hawk Ridge averages about 100,000 or so hawks through an
entire season from August until November. The Hazel Bazemore Hawk Watch in Corpus
Christi, Texas, pretty much directly south of there, often reports single day totals of more
than 100,000 hawks — sometimes as many as 400,000 — and averages about 720,000
hawks a year. The record flight there happened on September 28, 2004, with a total day's
count of 520,267 raptors including 13 species. Of that day's count, 519,948 were Broad-
winged Hawks.
