Annals of DDT: Rachel Carson was right, DDT hurts birds

April 6, 2014

Coming up on World Malaria Day 2014, and U.S. Congressional elections, we’ll start seeing repeated false attacks on Rachel Carson as the right’s most-favored representative of environmentalism, and those attacks will include calls to “end the ban” on DDT to roll back the “increase in malaria caused by the ban. ” Facts are that DDT was never banned in Asia nor Africa (not even under a 2001 anti-pollution treaty); Rachel Carson called for no ban on DDT, but instead urged use of “integrated pest management” (IPM)  to combat disease vectors, and IPM used broadly since 1999 has slashed malaria death totals and infections even more; and malaria deaths and infections started a downward trend in the 1960s that continues today, mostly without DDT.
This is one in an occasional series of posts to correct these hoax claims, with citations to information that readers may check for themselves. Much of this post appeared here earlier, in much longer form.

Rachel Carson was very careful in her 1962 book Silent Spring.  She offered more than 50 pages of citations to science papers and hard research to support what she wrote — a “don’t take my word for it, check it out for yourself” kind of honesty.

Still, today, there is an organized effort with broad success on the internet to smear Rachel Carson and hide the science she wrote about.  Standard from adherents to this insurgent anti-science movement include are claims that Carson’s book was wrong.  The title comes from a prologue of the book in which Carson described a spring in some future year, a spring which was unheralded by the songs and chatterings of birds.  Carson argued that, if humans do not stop to think about secondary effects of chemicals used, especially as pesticides, whole regions might be devoid of birds, dead from DDT poisoning.

Carson cited research from the U.S. Department of Agriculture and the U.S. Fish and Wildlife Service about just how deadly DDT could be to entire ecosystems.  She was particularly alarmed by research done at Midwestern universities, where DDT sprayed to save American elm trees from Dutch elm blight, quickly killed off most birds who came in contact with the stuff.  Dutch elm blight is spread by beetles, the targets of DDT in those sprayings.

In the 1950s, ornithologists, wildlife managers and bird watchers documented the pending demise of entire species of birds, especially raptors at the top of local food chains.  Audubon bird watchers throughout the eastern U.S. noted that migrations consisted of older birds only, with young and maturing birds appearing to have disappeared. Older birds mated, built nests, and laid eggs. Usually the eggs did not hatch, with chicks dying before the end of gestation.  In the few cases where young hatched, they generally died before they could migrate even one year.

Especially for the American bald eagle, this was a great disappointment. Eagles had been plentiful when European colonists migrated to North America, starting after Columbus’s voyages, 1492-1494.  By 1900, however, eagles had been hunted almost to extinction — well, they were extinct in some states.  Colonists, then farmers and ranchers, saw eagles as pests.  They ate fish the colonists wanted to catch for themselves.  Eagles would sometimes take a farmer’s chicken.  Cases of eagles taking larger prey are sparse to non-existent prior to the latter 20th century — but farmers claimed they did.  And so the birds were hunted mercilessly, simply to shoot them.

In 1911 the federal government tried to solve a many-states-wide problem, with a law protecting eagles from hunting.  It did little good.  In 1941 Congress passed a new law, with criminal penalties for people who poached eagles.  The decline of adult numbers slowed dramatically.  But that problem with hatching fledges stopped the recovery, at least so far as young birds who could replace those who died of old age or accidents.

Carson’s critics argue that eagles were never really in decline.  Steven Milloy and Gordon Edwards invented a fantastic tale that the Audubon Society annual Christmas Bird Count actually recorded an increase in eagle numbers, a false claim that Audubon certainly never made, based on a twisted misapplication of bird count methods.  USFWS and others noted the decline of eagles speeding up through the 1950s and 1960s.

Carson’s critics then will say that what plagued eagles was hunting and poaching, and not DDT.  While that was true prior to 1941, that was not the case after World War II when the laws were enforced well.

When studies indicated that DDT would stop birds from successfully breeding, Carson cited them. Her critics claim those studies were in error.

Double-crested cormorant chicks, dead in their nest from DDT-DDE poisoning; nest in the Columbia River estuary, in Oregon.  US Fish and Wildlife photo.

Double-crested cormorant chicks, dead in their nest from DDT-DDE poisoning; nest in the Columbia River estuary, in Oregon. US Fish and Wildlife photo.

But they were not.  In fact, not a single study cited by Carson in Silent Spring has ever been refuted by later peer-reviewed research, nor pulled back for any reason.  A decade after Carson’s death, researchers discovered that residual DDT in birds, especially eagles and other raptors, prevented the females from forming competent shells on the eggs they laid.  Even when the DDT doses were not high enough to kill the chicks outright, the shells could not survive the mother’s sitting on them.  The shells broke, and the chicks inside died.

DDT was a scourge to the American bald eagle, the brown pelican, the peregrine falcon, and osprey — and probably many other birds.

Healthy pelican egg on the left, and a DDT-affected pelican egg on the right.  Image from VCE Environmental Science.

Healthy pelican egg on the left, and a DDT-affected pelican egg on the right. Image from VCE Environmental Science.

 

Discover magazine carried an article about DDT and Carson’s book in November 2007Discover said that, since 1962 when Carson’s book was published, more than 1,000 peer-reviewed publications support Carson’s conclusions, a record remarkable in any branch of science.

In fact, Carson may have underestimated the impact of DDT on birds, says Michael Fry, an avian toxicologist and director of the American Bird Conservancy’s pesticides and birds program. She was not aware that DDT—or rather its metabolite, DDE—causes eggshell thinning because the data were not published until the late 1960s and early 1970s. It was eggshell thinning that devastated fish-eating birds and birds of prey, says Fry, and this effect is well documented in a report (pdf) on DDT published in 2002 by the Department of Health and Human Services’ Agency for Toxic Substances and Disease Registry (ATSDR). The report, which cites over 1,000 references, also describes how DDT and its breakdown products accumulate in the tissues of animals high up on terrestrial and aquatic food chains—a process that induced reproductive and neurological defects in birds and fish.

History also supports the scientists.  President John F. Kennedy tasked the President’s Science Advisory Council to check out Carson’s book, to see whether it was accurate, and whether the government should start down the path of careful study and careful regulation of pesticides as she suggested.  In May 1963 the PSAC reported back that Carson was dead right on every issue, except, maybe for one.  PSAC said Carson wasn’t alarmist enough, that immediate action against pesticides was justified, rather than waiting for later studies or delaying for any other reason. (The full text of the report may be obtained here.)

Rachel Carson was right.  DDT kills birds.  DDT threatened several species with extinction.

Carson’s science citations were verified by a select panel of the nation’s top biologists including entomologists, certified as scientifically accurate.   Since she published, more than 1,000 peer-reviewed studies have been performed that verify her findings on DDT’s harms to birds.

I have never found a contrary study published in any peer-review science journal, based on research.


Nene, once again more than just a crossword answer

March 26, 2014

Caption:  USFWS Refuge System ‏@USFWSRefuges -   Nene hatchings on Jas Campbell #Refuge are 1st in Hawaii in centuries http://bit.ly/1jBxFrT  pic.twitter.com/PK2l9PVa3v

Caption: USFWS Refuge System ‏@USFWSRefuges – Nene hatchings on James Campbell National Wildlife Refuge are first in [Oahu] Hawaii in centuries http://bit.ly/1jBxFrT pic.twitter.com/PK2l9PVa3v (this photo taken on Kaui, at the Kilauea Point National Wildlife Refuge). Photograph by Brenda Zaun/USFWS/Flickr Creative Commons

These great looking geese, known as Nene,  are thought to have descended from Canada geese blown off course; once they were common on many of the Hawaiian Islands, but by 1952 there were only 30 left.

Bones found on Oahu show they once thrived there.  A few birds — blown off course again, or looking for more territory? — moved to Oahu a few months ago, and have raised young.  Scientists are watching to see how it works out.

With short name featuring only two different letters, “Nene” is a popular crossword answer, and clue.  Some ornithologists half-joke that the familiarity among crossword enthusiasts was a huge aid in getting aid for the wild populations of the bird, and in getting the Endangered Species Act passed into law.

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Thank you, Rachel Carson!

March 16, 2014

An eagle gathering on the Mississippi River. 40 years ago, there may not have been this many eagles on the whole river. Cornell Ornithological Laboratory image.

An eagle gathering on the Mississippi River. 40 years ago, there may not have been this many eagles on the whole river. Cornell Ornithological Laboratory image.

Cornell Laboratory of Ornithology said:

A convocation of Bald Eagles at Dam 13 along the upper Mississippi River (between Illinois and Iowa). If this isn’t incredible enough, photographer Michael Descamps reports that this group represents less than half of the eagles that were gathered there the day of the photo. What an incredible event to witness and thanks for sharing!

When the Endangered Species Act passed, and when the new EPA banned most outdoor uses of DDT in the U.S., there may not have been this many eagles on the entire Mississippi River watersheds.  Today, we have healthier ecosystems across the nation, and a lot more eagles, osprey, peregrine falcons, and brown pelicans, among other wildlife.

Gee. Environmental protection works well sometimes.


Birds know better

February 19, 2014

[Species?] on a sign; distributed by USFWS; photo by Allie Stewart.

Eastern phoebe on a sign; distributed by USFWS; photo by Allie Stewart.

Borrowed from the Facebook page of USFWS Southeast Region:

This one is for the birds, or should we say bird watchers! In 2011 there were 47 million birders who generated $107 billion in industry output, 660,000 jobs and $13 billion in local, state and federal tax revenue. Take a look our birding report to learn more: http://1.usa.gov/1d0W06i (Photo: Allie Stewart)

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Sunrise at Hawk Mountain, Pennsylvania

October 4, 2013

Photograph posted on Facebook by the Hawk Mountain Sanctuary Association:

Sunrise at Hawk Mountain, Quelia Paulino, Hawk Mountain Sanctuary

Planning a trip to Hawk Mountain this weekend? Arrive early to enjoy great views of low-hanging fog and to see the sun peek out over the valley. It’s a great way to start any day. — with Quelia Paulino at Hawk Mountain Sanctuary Association.

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We remember

September 11, 2013

Stunning photo of a snowy owl, taken by Frank K. Schleicher (who holds the copyright), and shared by the Hawk Mountain Sanctuary Association.

Most stunning in the photograph:  Look behind the owl.

Photo of snowy owl, looking across New York Harbor, by Frank K. Schleicher

Photo of snowy owl, looking across New York Harbor, by Frank K. Schleicher


Return of the roadrunners

July 13, 2013

Our move to Texas in 1987 offered as one amenity, local roadrunners.

Camp Wisdom road was mostly two lanes then — it’s six, now.  Clark Road was two lanes.  It’s expanded to six, with a direct link to the freeway Spur 408.  Wheatland Road was two lanes.  You guessed it: Six now.

Not sure about baseball fields any more, but with roads, if you build ‘em, people will come.  The empty prairie and cedar forests favored by golden-cheeked warblers, and favorable to lizard-eating roadrunners, gave way to bulldozers putting up apartment complexes, strip shopping centers (still mostly vacant), self-storage businesses, and more roads.  Roads bring automobiles, and autos provide collision courses for roadrunners.

In the summer, I used to see a roadrunner at least weekly at the intersection of Camp Wisdom and Clark; once watched one hunt down a very large Texas fence lizard and dash off with the lizard dangling from either side of its beak.  In the era before electronic cameras.

All that development takes the habitat of roadrunners, and that is the slow death of much wildlife.  Roadrunners dwindled down.  About 2009 we discussed how rare they were.  In 2011 Kathryn and I saw one lone roadrunner along Old Clark Road in Cedar Hill, precariously living in a 50-yard swath between two roads (which are slated to be widened), sharing a railroad track.  Nothing since.

Mama and chick roadrunners

Mama roadrunner gives me the eyeball from the safety of the cedar tree, while the chick grooms. Is it safe to go out into the sun?

Until two weeks ago.  Kathryn called me, excited that she’d seen a roadrunner crossing Mountain Creek Parkway, where Wheatland Road dead-ends into it.  It’s good roadrunner weather.  We were happy to know at least one survived.

Then, last Thursday I was driving along Old Clark Road.  I brought along the Pentax K10D because I was hopeful of catching the hawk family living a block off of Wheatland and Cedar Ridge Roads.  A roadrunner dashed across the road from a small ranchette into a “vacant” field of wild prairie grasses dotted with Ashe cedars.  My experience is they are reclusive, and don’t like to be watched.  I grabbed the camera and got a couple of shots of the bird, running under a tree and meeting up with another, smaller one — a chick!

I doubled back and u-turned, hoping they might at least dash.  The larger one danced on the edge of the shadow of the tree for a minute, then uncharacteristically strutted out, hunting something to eat.  She got something that looked like a lizard, or a fantastically large grasshopper, and a few other tidbits from the grass.  She strutted around, and headed back to the shade, and to the younger one.

Mama Roadrunner flaps happily after ingesting a large something.

Mama Roadrunner flaps happily after ingesting a large something.

Roadrunners, the greater roadrunner, Geococcyx californianus (which means “Californian Earth-cuckoo,” a description of many politicians in the Golden State, perhaps).

I shot stills, with a 50-200 mm telephoto zoom, and I got a bunch of shots.  I strung them together in Windows Moviemaker.

Are the roadrunners doing okay?  Not really.  They’re not gone, but much of their old habitat disappeared from this hill, the highest point in Texas between the Louisiana border and the Rockies — swallowed by human development, homes, suburban shopping, and the roads that go with that development.

How are roadrunners doing in your area?  Got pictures?  (Cindy Knoke has a longer telephoto than I’ve got, and photos to prove it; go see.)

Greater Roadrunner running

Greater Roadrunner doing what roadrunners to, back to the shade of a cedar tree and her chick. It was 102 degrees F, after all.

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For the birds, scientists at work

July 2, 2013

A scientist at work:

Amanda Holland with one of her research subjects, in South Carolina

Amanda Holland with one of her research subjects, in South Carolina

Kathryn’s cousin, Amanda Holland, moved from researching condors in California, to buzzards in Georgia and South Carolina (for the University of Georgia, I think).

Here she is with one of her research subjects.  Much lore is out there about handling carrion-eating birds for research — they vomit on you only if they like you, for example — but wholly apart from that, how great is this photo of a scientist at work?

I told her to copyright the photo (it is), and to hand on to the meme.  Can’t you see a character in Game of Thrones, or some other fantasy, who carries her own vultures to clean up after she devastates some other army in battle?

Eagles and falcons and owls are okay, but what other bird could conceal the results of the battle, so the warrior princess could move on in stealth?

Science field work looks like great stuff.  My experience is that it’s tiring, and sometimes lonely (though in very beautiful locations) — but the psychic rewards of actually increasing knowledge keep a lot of scientists going.  There’s not a lot of money in it.

Look at the friends you could make!


Birdbrains, in Canyonlands National Park

May 6, 2013

Bewick's Wrens nesting in skull of a bull, Canyonlands NP

From Canyonlands NP Facebook page: “View from the Maze: A pair of Bewick’s Wrens makes a nest in the brain cavity of an old bull’s skull. Where bovine ruminations once roamed a quick feathered flickering now prevails. If your skull ended up in a tree what species of bird would you like your brain cavity to host? (GC)”

Years ago in the Salt Lake Valley my sister Annette had a home on Wren Road.

One day she and a friend watched birds scurrying all over the property, plucking nesting materials.  “I wonder what kind of birds those are,” my sister said.

“Did you ever wonder why they named it ‘Wren Road?’” her friend replied.

If you want your bird watching friends to think you’re experienced at it, remember Bewick’s, as in “Bewick’s wren,”  is pronounced like the automobile, “Buick’s.”

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Grosbeak!

May 1, 2013

Our goldfinches left several weeks ago.  The cedar waxwings came through in at least three big waves, starting in February (and the last just over a week ago).  House finches moulted, and the breeding males have bright red heads. Migrating robins left us by the end of January, but a lot more residents stayed with us.

We have at least one, and maybe three cardinal families.  A black-capped chickadee family stuck around.  Haven’t seen a titmouse in a month, but I think they’re still in the neighborhood.  The black-chinned hummingbird family is back, and maybe a few other hummers.  The resident blue jays and white-winged doves duke it out every day.  Carolina wren stayed, and may have already fledged; but there are too many wrens for one family — is that a Bewick’s wren?

What’s THAT?

White winged dove and rose-breasted grosbeaki

White-winged dove, left, can’t scare away the rose-breasted grosbeak from the songbird feeder. Photo by Ed Darrell

IMGP4861

Look closer. Photo by Ed Darrell

It’s a rose-breasted grosbeak, Pheucticus ludovicianus.  It seems late for migrating birds, but only because so many migratory species migrate earlier these days.

Haunts of the rose-breasted grosbeak, from Cornell University's ornithological laboratory.

Haunts of the rose-breasted grosbeak, from Cornell University’s ornithological laboratory.

Would love to have a grosbeak family, but the Cornell ornithologists say this is fly-through territory.  Maybe that explains why it won’t scare by the white-winged dove, Zenaida asiatica.  Dallas is the western edge of the grosbeaks’ migratory path, but the eastern edge of the dove’s territory.  They probably don’t see much of each other.

We don’t even advertise clean restrooms.

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Backyard birds: Goldfinch at the feeder

March 12, 2013

No, he’s not particularly gold — but this is winter, and if he’s going to get his breeding plumage, it will come in a couple of weeks.

We’ve had Niger thistle seed feeders out for years; this year one goldfinch (Spinus tristis) finally started to visit.  We’ve had as many as four at a time — but they’re probably headed north soon.

Here’s a shot of our first guest, from a couple of weeks ago.

Goldfinch at the feeder

A goldfinch male, checking out the feeder before bringing in his buddies — we hope.

If you’re north of Dallas, and you see this guy at your feeder this summer, tell him “hello” from us.

The non-breeding plumage isn’t so flashy as the bright yellow of the breeding males.  Some of the finches settle in to a beautiful, smooth olive-drab livery for much of the winter.  Close up, they look like good pen-ink-drawings by a master artist.

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Backyard birds: A convention of white-winged doves

February 8, 2013

The white dove was a short-lived interlude; the white-winged doves seem to be with us constantly.

One family in 2011; two families in 2012 — and our yard isn’t that big.

A very early version of the birds who visited, befriended, and plagued Snoopy — this drawing, while faithful to Shultz’s work, was done by another artist.

Earlier this week I looked out, and it looked like the early “Peanuts” comic strip when Snoopy opened his dog house to a group of pigeon-like birds for their poker game.  The birds took advantage of Snoopy’s largesse, and nearly over-ran him.  (Woodstock was a product of that flock of birds, the last remaining vestige by Charles Shultz‘s death.)

At least they didn’t drink our beer and try to make off with the Picasso.

White-winged doves are really too big for any of our feeders -- but what are you going to tell a rampaging herd of them?  Photos by Ed Darrell - use encouraged with attribution.

White-winged doves are really too big for any of our feeders — but what are you going to tell a rampaging herd of them? Photos by Ed Darrell – use encouraged with attribution.

White-winged doves crowding at the bird feeders

Enough doves to frighten Alfred Hitchcock — Two of these birds is too many for either side of this feeding station. How many do you see here?

White winged doves jostle for position at the feeder.

Not enough room for all, and so they jostle and push each other off the feeders. See the display of the white stripe on the wings of one of our subjects here, from which the species gets its name.

Blue jays enforce the “too-long-or-too-many-at-the-feeder” rules here, but they can be distracted by peanuts put out by neighbors.  In any case, they were absent when we needed them.

We used to have mourning doves, but at some point in the last five years this bunch pushed them out.  We may be the only ones on the block who noticed.  (Yes, it’s “mourning” dove; Duncanville’s having misspelled it on “Morning Dove Lane” is their error.)

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Mystery white dove

February 3, 2013

It was last April.  Kathryn’s garden near the patio needed some work, and of course there are all the plants in pots, including the orange tree (which has since been joined by a pomegranate).

Birds visit often — we hang three or four birdfeeders.  Cardinals, house finches, the Carolina wren and her family, and a lot of white-winged doves commonly hang around.

Of a sudden a flutter of wings — and there he was:

White dove

Where did this dove come from? For a few weeks in the spring, it haunted our yard.

We assumed it was male, but we have no way of knowing for sure.  At one point it seemed to make mating advances on some of the white-winged doves — but who knows.

The bird followed Kathryn around.  It ignored the feeders farther out in the yard, and concentrated on the feeders on the patio.  Then it would land on our patio table and watch.

Sometimes it splashed in the birdbaths.

White dove in the yard.

The bird appeared at ease around people. It would watch us work or play in the back yard.

Difficult to miss — the white was positively glowing.  When it flew in, it’s path suggested it came from a house up the alley a ways.  Was it a refugee from some cote, an escapee?  Or was it a trained bird just out for exercise?

A few times it arrived in the morning, and hung around for an hour or two.    Its usual pattern was to arrive in the early evening, grab a few seeds, do a lot of watching, and disappear.

With its color, we feared it would be a target for hawks.

White dove ron the roof.

Where it flew to roost, we couldn’t determine.

One day it flew off, and didn’t return.

The mystery dove.  Where did it come from, was it tame?  Why was it here?  Where did it go?

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Occasional Tuesday tweet: Wren on the rose, Bewick’s or Carolina?

January 22, 2013

I’ve been calling these guys Bewick’s wrens (Thryomanes bewickii) for a couple of years, based on an identification I made a couple of years ago — but checking today to be sure, I’m thinking this is a Carolina wren (Thryothorus ludovicianus) instead.

In any case, a couple of days ago it paused for a few minutes in our backyard rose arbor, long enough I could try to get a good shot with just a 200mm telephoto, and with colors dulled by the window.

Carolina wren, perhaps, in Dalls

Wren in the rose arbor — ruddy color suggests it’s a Carolina wren, but I’ve been calling it a Bewick’s wren; pausing for its photo on Inauguration Day – Photo by Ed Darrell

Bewick’s wrens probably have more grey on their bellies; this one looks ruddy enough to be a Carolina wren.  (I just learned “Bewick’s” is pronounced like “Buicks.”)

Wrens stick around all winter now; they didn’t just over a decade ago.  This family has been with us for at least three years — two young this year successfully fledged.  By now it’s almost impossible to tell which are the young, which the parents.

Gulf fritillary on blue porterweed, Dallas, Texas - Ed Darrell photo

Gulf fritillary butterfly on blue porterweed — a few feet from the rose arbor where the wren posed, but months apart. Photo: Ed Darrell

On our patio we have a saga continuing with Gulf fritillary butterflies (Agraulis vanillae), their larva, and passion vine.  It seems our neighbors eradicated passion vine, so when the frits start moving north in the spring, they find our passion vines as the only ones in town.  The females go nuts laying eggs, and at some point we have a surplus of larva who denude the vines in a week.  Late hatching larva probably die off.

The butterfly books suggest that we cull the larva, but we don’t have the heart.  At some point in the spring the wrens wake up to the issue, and they cull the larva for us.  The vines recover, a new wave of frits hatch out, and the cycle begins again.  From June through September, the passion vine loses any leaves it puts out within 48 hours, usually.  But the wrens probably eat well.

The wrens seem never to perch where we can see them when they sing.  I suspect these little guys of having a much better voice than most wrens, but the great arpeggios I hear may be another bird, perhaps a warbler, that I just don’t know (good reason to go spend time at the local Dogwood Canyon Audubon Center, yes?).

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White-breasted nuthatch in action

July 21, 2012

White-breasted nuthatch (Sitta carolinensis) (male?), cracking a nut on a pine limb, Peaceful Valley Scout Ranch, Colorado, July 2012:

White breasted nuthatch in action, Peaceful Valley Colorado, 2012 - photo by Ed Darrell - 061

White-breasted nuthatch (Sitta carolinensis)works over a seed, Colorado, 2012 – photo by Ed Darrell

 


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