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Over increasingly large areas of the
United States, spring now comes unheralded by the return of
the birds, and the early mornings are strangely silent where
once they were filled with the beauty of bird song.
Rachel Carson; Silent Spring
In 1962, the biologist Rachel Carson
alerted the world to the dangers pesticides pose to wildlife
and humans. DDT had entered the food chain and was being bioaccumulated
(concentrated) in animals. Birds like the Brown Pelican, Peregrine
Falcon, Sparrow Hawk and Osprey were suffering significant
reductions in their populations because DDT caused reproductive
dysfunctions that resulted in thin-shelled eggs. Rachel Carson's
exposé of the effects of chemical pesticides on higher
animals resulted in worldwide concern and generated public
demands for the protection and preservation of the environment.
DDT was banned in the U.S. in 1973, but its effects linger
today; many species still show concentrations of DDT.
The ban on DDT only gave rise to new pesticides; in the words
of Ms. Carson, "Under the philosophy that now seems
to guide our destinies, nothing must get in the way of the
man with the spray gun."
Today, new generations of pesticides like organophosphates
and carbamates are killing wildlife and threatening human
health.
What is a pesticide?
As the word implies, a pesticide is a "pest killer".
A pest is defined as an organism that is a nuisance to humans
or that is unwanted by humans (termites, cutworms, mosquitoes,
tent caterpillars, etc.) Interestingly, a "pest"
has no organic, biological, environmental or genetic definition
- it is simply an annoyance or inconvenience to humans. Insect
pests damage crops and gardens, spread diseases or are simply
annoying. The chemicals used to "control" them,
however, are indiscriminate... they are designed to affect
a bodily organ or disrupt a bodily process, but any other
organism that has that organ or that process is affected,
too. A pesticide can't differentiate between a cutworm or
an aphid or a monarch butterfly - nor can it differentiate
between a cutworm or a shrew or a bird. Pesticides deliver
their payload indiscriminately.
It seems to go unnoticed that pesticides, in spite of their
deadly legacy, do not achieve their objectives - pesticides
have been used to control mosquitoes for a century, yet mosquitoes
are no closer to extinction. Unfortunately, the same cannot
be said for innumerable other species.
How does a pesticide
work?
Environment Canada, Canadian Wildlife Service
Pesticides and Wild Birds
"A pesticide works by disrupting a vital bodily process,
such as photosynthesis in plants, or by destroying a major
organ, such as a caterpillar’s intestine. Organophosphates
and carbamates, the most common insecticides in use today,
are known as "cholinesterase-inhibiting pesticides,"
because they kill by interfering with an enzyme vital for
nerve transmission. Pest populations exposed to repeated applications
of a pesticide may evolve genetic resistance to it, so that
the pesticide no longer works".
How does a bird come into contact with a pesticide?
"A pesticide’s form determines how a bird may come
into contact with it - by mistaking it for food or drink,
absorbing it through the feet, inhaling it, or rubbing against
a contaminated surface and then ingesting it while preening
its feathers. Granular pesticides (mixed with clay, sand,
or dried pieces of corn cob) are especially hazardous to pecking
birds, because the birds may mistake the granules for food
or grit, which they use to grind their food".
Birds ingest pesticides by:
- feeding on insects in an area that has been freshly sprayed
- absorbing the chemical through skin and lungs
- ingesting pesticide runoff in water feeding or swimming,
bathing and preening.
Are some birds
more vulnerable than others?
Environment Canada, Canadian Wildlife Service
Pesticides and Wild Birds
"Some birds are more likely than others to be exposed
to pesticide residues. One group at risk is birds that eat
large quantities of foliage that might have been recently
sprayed, such as waterfowl and game birds. Another group at
risk is seed-eating songbirds, which are attracted to insecticide
granules and pesticide-treated seeds. Species that gorge on
pest insects, such as grasshoppers, are particularly vulnerable
in times of pest outbreak. Finally, scavengers and predators
that take slow or disabled prey are at a high risk of ingesting
other birds or mammals that have been poisoned."
How serious is
this problem?
American Bird Conservancy
"Some pesticides can, and do, kill birds - songbirds,
gamebirds, raptors, sea and shorebirds, among others. 672
million birds are directly exposed each year by pesticides
on farms alone - according to one conservative estimate -
and 10% of these, or roughly 67 million birds, die."
Canadian Wildlife Service
http://www.cws-scf.ec.gc.ca/nwrc/pesticid.htm
"In late 1995 and early 1996, more than 4,000 carcasses
of Swainson's Hawks, some with bands showing that their breeding
grounds were in Canada, were counted in the farm fields of
Argentina. Farmers had sprayed organophosphate insecticides,
including the very toxic monocrotophos, to control a grasshopper
outbreak. Although precise counts were not possible, the total
kill was conservatively estimated at over 20,000 hawks. Such
die-offs may be contributing to a recent decline of this species".
National Wildife Federation
"A biologist with the U.S. Forest Service in Yreka,
California, Woodbridge has been studying Swainson's hawks
for 15 years and watching them decline by an estimated 90
percent today from their numbers in the late 1940s. Researchers
in western Canada have noticed a similar trend".
McGill University
"Well documented bird kills have been caused by the organophosphates
diazinon, isofenphos, and chlorpyrifos with one kill involving
thirty to forty thousand birds".
Canadian Wildlife Service
"Between 1990 and 1996, a third of the 100+ Bald Eagles
taken dead or moribund to raptor rehabilitation centres in
the Fraser delta of B.C. had been poisoned by pesticides.
They were exposed through scavenging of waterfowl poisoned
by granular insecticides in nearby fields. Kills were recorded
with the insecticides fensulfothion, carbofuran, phorate,
terbufos, and fonofos."
McGill University
"Carbamate insecticides have a mode of action similar
to the organophosphates and, like the organophosphates, some
kill birds at low doses. Carbofuran, which has been estimated
to kill one to two million birds annually in the U.S., is
probable the best known example".
Do these pesticides
affect just birds?
David Suzuki Foundation
"Some of the more potent of these chemicals also "bioaccumulate"
up the food chain and end up in toxic amounts in marine mammals".
U.S. Geological Survey
"Thousands of birds representing more than 50 species
including waterfowl, passerines, colonial waterbirds, shorebirds,
gulls, raptors, and others have been killed in these incidents.
A die-off incident can involve a few birds of one species
or hundreds of birds of a variety of species. Gross necropsy
findings in birds dying from OP and carbamate toxicity were
minimal. Lung edema and hyperemia (see glossary) were the
predominant findings when lesions were observed. Mammals such
as Virginia opossum (Didelphis virginiana), raccoon (Procyon
lotor), and coyote (Canis latrans) were occasionally involved".
Butyltin residues in southern sea otters (Enhydra lutris
nereis) found dead along California coastal waters. Kannan,
K., K.S. Guruge, N.J. Thomas, S.Tanabe, and J.P. Giesy. 1998.
Environmental Science & Technology 32(9): 1169-1175.
Accumulation pattern of organochlorine pesticides and polychlorinated
biphenyls in southern sea otters (Enhydra lutris nereis) found
stranded along coastal California, USA. Nakata, H., K. Kannan,
L. Jing, N. THOMAS, S. Tanabe, J.P. Giesy. 1998. Environmental
Pollution 103: 45-53.
U.S. Fish & Wildlife Service
"Pesticides are used in nearly every home, business,
farm, school, hospital and park in the United States and are
found almost everywhere in our environment. In fact, recent
studies of major rivers and streams documented that 96% of
all fish, 100% of all surface water samples and 33% of major
aquifers contained one or more pesticides at detectable levels
(Gilliom, Robert). Pesticides were identified as one of the
15 leading causes of impairment for streams included on States'
Clean. Pesticides have also been identified as a potential
cause of amphibian declines and deformities and as one of
a number of potential causes of pollinator species' declines
and declines of other beneficial insects".
Audubon
"Cholinesterase-inhibiting pesticides have been linked
to nervous-system disorders in humans. Young children are
particularly vulnerable to exposure to organophosphate and
carbamate pesticides. In humans, overexposure can cause rapid
heartbeat, dizziness, blurred vision, nausea, abdominal cramps,
wheezing, chest tightness, throat spasms, and, in severe cases,
death by respiratory failure or cardiac arrest".
"A major threat to sustainable ecosystems and biological
diversity is agriculture’s continued reliance on high-risk
pesticides. Every year US agriculture introduces into the
environment over 900 million pounds of pesticides in producing
food and fiber consumed worldwide. While contributing to the
production of an abundant and affordable food supply, continued
reliance on pesticides comes at a cost in terms of harm to
people, wildlife and the environment".
“Common sense tells us that rather than pouring nearly
3 billion pounds of pesticides on our food - and then trying
to wash them off -commission scientific studies about them
- worry about how risky they might be - we ought to be figuring
out how to use fewer pesticides in the first place.”
Carol Browner, Administrator, US Environmental Protection
Agency."
"...we have put poisonous and biologically potent
chemicals indiscriminately into the hands of persons largely
or wholly ignorant of their potentials for harm. We have
subjected enormous numbers of people to contact with these
poisons, without their consent and often without their knowledge.
It is the public that is being asked to assume the risks
that the insect controllers calculate. The public must decide
whether it wishes to continue on the present road, and it
can only do so when in full possession of the facts."
"The choice, after all, is ours to make. If, after
having endured much, we have at last asserted our 'right
to know,' and if, knowing, we have concluded that we are
being asked to take senseless and frightening risks, then
we should no longer accept the counsel of those who tell
us that we must fill our world with poisonous chemicals;
we should look about and see what other course is open to
us."
Rachel Carson (Silent Spring, 1962)
For more information on pesticides and wildlife, choose one
of the topics below.
American Bird Conservancy (ABC) is a 501(c)3 not-for-profit
dedicated to the conservation of wild birds and their habitats
in the Americas. The fundamental role of ABC is to build coalitions
of conservation groups, scientists, and members of the public,
to tackle key bird priorities using the best resources available.
Audubon's website "Backyard" page offers information
on pesticides and alternatives: "The Killer in your yard:
Each time you douse your lawn with pesticides, you could be
poisoning birds, wildlife, even the neighbour's kids".
page is full of good
information, symptoms of affected birds.
The lab is a membership institution interpreting and conserving
the earth's biological diversity through research, education
and citizen science focused on birds. Cornell's website is
searchable and includes many articles on pesticides and birds.
"Established in 1991, the DAPTF consists of a network
of over 3,000 scientists and conservationists belonging to
national and regional working groups which now cover more
than 90 countries around the world. The mission of the DAPTF
is to determine the nature, extent and causes of declines
of amphibians throughout the world, and to promote means by
which declines can be halted or reversed."
Canadian Wildlife Service Website Hinterland Who's Who (species
accounts) "Pesticides and Birds" Environment Canada
Canadian Wildlife Service: Hinterland who's who website: fact
sheet: Pesticides and Wild Birds. This excellent fact sheet
was written by Pierre Mineua, one of North America's foremost
experts on pesticides and birds. The full text can be read
on the website.
The Canadian Wildlife Service conducts research on the impact
of pesticides on birds and other wildlife species. A brief
summary of this research, as well as selected titles of scientific
publications, can be obtained from the following Internet
web site: ,
or by writing to the address on the site.
Michigan Wildlife Diseases website."DDT and other chlorinated
hydrocarbon pesticides: Transmission and Development; Clinical
Signs; Pathology; Treatment
National Wildlife Health Center
National Biological Service National Wildlife Health Center
report: "Wildlife Mortality Attributed to Organophos-phorus
and Carbamate Pesticides".
The Northwest Coalition for Alternatives to Pesticides works
to protect people and the environment by advancing healthy
solutions to pest problems. Articles on pesticides topics,
free fact sheets and downloads on safe alternatives to pesticides.
Downloads and fact sheets on dealing with insects in non-harmful
ways.
Pesticides Impact on Wildlife
This website offers excellent articles and excerpts from journals,
including: PCBs Are A Health Risk for Humans and Wildlife;
The Summer the Rivers Died: Toxic runoff from potato farms
is poisoning P.E.I.; The Second Silent Spring (PDF 121K);
"Sharp Decline in UK Bird Populations"; Larvacide
linked to frog deformities; A Wind-Borne Threat to Sierra
Frogs; Dr. James LeClair, Assistant Professor, Department
of Molecular Biology, at the Scripps Research Institute in
La Jolla, CA. offers a review of 'Amphibian Decline Research'
efforts; Summary of Workshop on Central North American Amphibian
Deformities. Minnesota Pollution Control Agency's Hot Topic
page on Deformed Frogs in Minnesota includes background information,
fact sheets about deformed frogs, pictures as well as links
to other sites on the WWW. "Frog deformities Pose a Mystery",
an article by Dr. Stanley K. Sessions, Department of Biological
Sciences, Hartwick College in Oneonta, NY. "Fish Kill
on Prince Edward Island" ; Pesticide Impacts on the Swainson's
Hawk; PAN's new report, Disrupting the Balance: Ecological
Impacts of Pesticides in California is now available.
A clearinghouse and library with information at both scientific
and layperson levels on pesticide-related issues, Rachel Carson
Council provides answers to the public, produces various publications
clarifying pesticide dangers, brings alternative pest controls
to the public's attention, and presents conferences and workshops
for the public and the scientific community.Please remember
that migrating birds need insects to eat to survive and raise
their young...
Division of Environmental Quality Pesticides and Wildlife
Pollution is one of the American public's greatest environmental
concerns. Like the proverbial "canary in the coal mine,"
fish and wildlife often signal pollution problems that ultimately
affect people and their quality of life. The U.S. Fish and
Wildlife Service (Service) is the main federal agency dedicated
to protecting wildlife and their habitat from pollution's
harmful effects, helping to create a healthy world for all
living things.
National Wildlife Health Center
The National Wildlife Health Center (NWHC) is a science center
of the Biological Resources Discipline of the United States
Geological Survey. The NWHC was established in 1975 as a biomedical
laboratory dedicated to assessing the impact of disease on
wildlife and to identifying the role of various pathogens
in contributing to wildlife losses. There are a number of
articles and documents on this site, including :Amphibian
Malformation and Decline: Frog malformations have been reported
from 42 states. The broad geographic distribution of these
malformations warrants national attention. Scientists at the
USGS National Wildlife Health Center in Madison, Wisconsin,
are studying this problem in an effort to document its scope
and to determine the causes of the observed malformations".
Global Toxics Initiatives
Contamination from toxic chemicals is now pervasive and global.
Wherever scientists look - the tropics, marine systems, industrial
regions, the Arctic - they find the impacts of industrial
chemicals and pesticides. Wildlife, people, and entire ecosystems
everywhere are threatened by chemicals that can alter sexual,
neurological, and behavioral development; impair reproduction;
and undermine immune systems. Recognizing the far-reaching
effects of pollution to wildlife throughout the world, WWF
continues to investigate toxic chemicals and their relationship
to biodiversity, seek alternatives to harmful synthetic agents,
and educate the public and policymakers to the dangers of
toxics. WWF's goal is to stop, and reverse, the accelerating
degradation of the environment, and to help build a future
in which humankind lives in harmony with nature. Toward that
end, the overall goal of WWF's Global Toxics Initiative (GTI)
is to end threats to biological diversity from toxic industrial
chemicals and pesticides - especially endocrine disrupting,
bioaccumulative, or persistent chemicals - within one generation
- by no later than 2020.
Ecotoxicology and Environmental Safety
Academic Press
Ecotoxicology and Environmental Safety publishes studies
that examine the biologic and toxic effects of natural or
synthetic chemical pollutants on animal, plant, or microbial
ecosystems and their routes into the affected organisms. Reports
that discuss the entry and fate of chemicals through the biosphere
are emphasized. 1993 to present Academic press archives: table
of contents and abstracts for each issue; subscription
Journal of Pesticide Reform
The Journal of Pesticide Reform is NCAP's nationally recognized
quarterly magazine, now in it's 21st year of publication.
By joining NCAP, you receive the journal as a membership benefit.
Pesticide fact sheets, alternatives fact sheets for common
pest problems, and helpful information on how to take action
for change are featured in JPR. Each issues also includes
updates on NCAP's work, news on pesticide issues, and reviews
of books and videos. The index to the Journal of Pesticide
Reform and NCAP News (earlier title) covers volume 4 (1984)
to the present. Each issue is indexed completely, including
not only the main articles but also editorials, announcements,
news, letters, etc. The index does not have the articles themselves,
but lets you know what was published in the Journal on a particular
topic or by a particular author. To receive a free copy of
the latest issue of the Journal of Pesticide Reform, fill
out the form on the website.
Pesticide Biochemistry and Physiology Academic Press
Pesticide Biochemistry and Physiology publishes original scientific
articles pertaining to the mode of action of plant protection
agents such as insecticides, fungicides, herbicides, and similar
compounds, including nonlethal pest control agents, biosynthesis
of pheromones, hormones, and plant resistance agents. Manuscripts
may include a biochemical, physiological, or molecular study
for an understanding of comparative toxicology or selective
toxicity of both target and nontarget organisms
Academic Press archives 1993 - present: table of contents and
abstracts for each issue; subscription
Froglog
Newsletter of the Declining Amphibian Populations Task
Force of the World Conservation Union's Survival Commission
GREENLines
Daily newsletter of GREEN(a project of Defenders of Wildlife'
designed to serve grassroots wildlife and wildlands advocates.)
Pesticide News
Newsletter for the most comprehensive quarterly information
on pesticide problems and alternative developments, with extensive
articles, resources, news and reviews on UK, European and
global developments.
Science News Online Magazine
Online articles, archived articles.
And No Birds Sing:Rhetorical Analyses of Silent Spring
by Craig Waddell (Editor), Linda Lear (Afterword), Paul Brooks
Hardcover: 232 pages
Southern Illinois Univ Pr
ISBN:0809322188
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Ishmael:
by Daniel Quinn
Paperback: 263 pages
Bantam Books
ISBN:0553375407
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Let the Mountains Talk, Let the Rivers Run:A Call to Those Who Would Save the Earth
by David Ross Brower, Steve Chapple
Paperback: 208 pages
New Society Pub
ISBN:0865714118
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Silent Spring:
by Rachel Carson, Albert Gore, Jr.
Paperback: 368 pages
Mariner Books
ISBN:0395683297
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