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The Stewardship Lectures 2006
February 23rd, 2006
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 On
February 23rd, 2006 Dr. Noel Snyder presented
a talk entitled “Extinct and Vanishing Birds of North
America: Their Causes of Decline”.
Dr. Snyder
gave many examples of extinct and endangered bird species (with
causes of decline mainly due to human depredation) in an
engaging slide show presentation.
Some noted
examples of extinct and highly endangered birds included:
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Painted Vulture
(extinct by 1800s)
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Labrador Duck
(last seen in 1875)
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Passenger Pigeon
(extinct in early 1900s, used to be the most abundant bird
in North America)
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Eskimo
Curlew
(extremely rare for many decades, last accepted sightings in
late 20th century)
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Great
Auk
(extinct in 1844)
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Thick-billed Parrot
(numerous in Mexico, but extinct in USA)
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Trumpeter Swan
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Whooping Crane
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Dusky
Seaside Sparrow
(Suggested resource: “Shadow
and a Song - the Struggle to Save an Endangered Species"
by Mark Walters)
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Bachman’s Warbler
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Snail
Kite
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Carolina Parakeet
(To read about possible hypotheses for extinction in the
U.S.A., click here to
read Noel Snyder’s book)
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 Dr.
Snyder discussed the research surrounding the California Condor,
once on the brink of extinction and still highly endangered today.
Initial beliefs on the decline of the California Condor included
habitat destruction and DDT in the environment causing thinness in
bird shells. In the 1980s, when scientific advances allowed for
radio-tracking of birds, scientists made an interesting and
unexpected discovery. The condor population was actually declining
due to lead poisoning resulting from bullets lodged in the carcasses
of hunted animals. The story of California Condor is a powerful
example of how necessary it is for a thorough scientific
investigation when examining causes of wildlife population decline,
since causes for endangerment of one species are not necessarily
applicable to other species.
Dr. Snyder
also talked briefly about the extinction of the Ivory-Billed
Woodpecker. Despite a wide-spread belief that the extinction of this
large bird was caused by loss of habitat, Dr. Snyder believes
another more possible explanation can be high predation by humans.
As with so many birds that are extinct, however, there is not
sufficient data available to scientifically verify either
hypothesis.
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As a field
biologist working mainly with the US Fish and
Wildlife Service, Dr. Snyder has conducted research
and written extensively on some of North America's
most highly endangered birds, including the
California Condor, the Everglade Kite, the Puerto
Rican Parrot, and the Thick-billed Parrot. His
efforts have been focused on the process of
determining causes of endangerment and devising
recovery strategies. His recent research interests
have centered on the extinct Carolina Parakeet and
perhaps not extinct Ivory-billed Woodpecker,
re-examining traditional explanations for their
declines. In addition, he maintains an active career
as a cellist, giving regular concerts in Arizona and
New England. To see books written and edited by Dr.
Snyder,
click here.
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