Cormorants rarely seen in lakes until recent years
January 10, 2002
BY ERIC SHARP
Detroit Free Press
Mostly because of the effects of the pesticide DDT,
cormorant numbers fell dramatically throughout their range
until the federal government decided to protect them in
1972. But the feds ignored the fact that on the Great
Lakes, cormorants are an exotic species that arrived only
within the memory of people still living here.
Twenty-five years ago, cormorants were rare
enough on the Great Lakes that people would point out the
bird if they saw one while they were out fishing.
Today, there are so many cormorants in some places that
they have to take a number to find a piling to sit on
and dry their wings. They also are showing up in increasing
numbers on smaller inland lakes where they were never
seen 10 years ago.
Archaeologists have learned from examining Indian rubbish
dumps that cormorants weren't common on the Great Lakes
in prehistoric times. Indians made use of every part of
an animal, including hollow bird bones for whistles, and
there's no indication cormorants were used for anything.
The U.S. Fish and Wildlife Service says cormorants came
to the Great Lakes around World War I, and their numbers
increased steadily until they were nearly wiped out by
DDT after World War II. Older commercial fishermen say
that even before World War II they kept cormorants under
control by freeing pigs on the islands where cormorants
nested. The pigs' diet included cormorant eggs and baby
Pollution reduced cormorant numbers so much that by
1970 only 89 nests were found in the region. The Fish
and Wildlife Service blamed the cormorant decline on "use
of the pesticide DDT, killings by humans and the overall
declining health of many ecosystems, especially that of
the Great Lakes."
But the cormorant decline stemmed almost entirely from
DDT and other severe pollution problems. Humans directly
killed only a small number of the birds.
By Eric Sharp