For readers who have been concerned with birds feeding on other birds,
as nature has demanded for millenia, here is news that our species has
been killing birds in a misguided attempt to thwart nature. The folks at
USDA have provided final numbers of cormorants killed during 2007 in an
effort to control damage alleged to other bird species and vegetation in
Ohio.
        The cumulative take for 2007 was 3,689 double-crested cormorants in
Ohio, during 13 "damage control activities," eleven conducted by our
Division of Wildlife, with two others conducted cooperatively by ODOW,
the USF&WS (Ottawa NWR), and the USDA's Wildlife Services. This compares
with 5,868 taken in 2006.
        The report mentions the culling's effects on other species. We are
invited to rejoice that 41% of other waterbirds stayed on their nests
while cormorants were being shot. The DOW estimated that disturbed birds
were absent from nests for approximately 7.4 +/- 0.7 minutes on average
during these absences. A number I'd like to see documented.
        Authorities estimated that decreases in nest numbers for cormorants,
great egrets, and great blue herons decreased ~25% this year because of
severe thunderstorms with high winds, not because of cormorants;
black-crowned night-herons, which nest later, were less affected, and
suffered deficits of only 4%. Still, the numbers of great egret and
great blue heron nests counted in 2007 were said to be within 10% of the
mean estimates for the previous five years. Great egret nest numbers
remained stable at Turning Point Island in Sandusky, where BCNH nests,
after increasing 50% in 2006, decreased by 40% in 2007, "perhaps
demonstrating the variability of Night-heron nest numers at that
location." GBH numbers at Green Island fell by 30% in 2006, but
increased by 50% in 2007.
        The report is said to demonstrate that the cumulative impact of
cormorant culling is "biologically insignificant to nonexistent" on
non-target species. It does not mention that culling has not
benefited co-nesters' populations, either; i.e., the numbers of great
blue herons, great egrets, black-crowned night-herons, and the small
numbers of other allied species has not increased with culling of DCCO,
but has rather remained more or less stable for many years. In other
words, our wildlife professionals have killed thousands of cormorants
over the past three years, but have nothing to show for it in terms of
increased populations of co-nesters. In fact, in spite of growing
cormorant numbers, no diminution of co-nesters has been demonstrated
over the past 12 years, except for the storm-related numbers of both
cormorants and their co-nesters last year.
        You may draw your own conclusions by asking for the "Monitoring Report
for Environmental Assessment for Reducing Double-crested Cormorant
Damage in Ohio" from USDA/APHIS, 6929 American Parkway, Reynoldsburg, OH
43068.
Bill Whan
Columbus

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