The National Audubon Society is in the midst of its annual "Christmas Bird Count," which is mostly an unscientific "bird feeder" bird count done when those birds which are at greatest risk of decline (i.e. neo-tropical migrants including most grassland birds) are actually down south in Mexico, the Caribbean and Central and South America.
In short, this is the wrong time of year to count birds that are truly at risk!
That said, the 111-years worth of data collected by the "Christmas Bird Count" does have some use, if for no other reason than to prove that one of the biggest fables about Bald Eagles and Osprey is more than a small lie.
What's the story? Simple: that Bald Eagles and Osprey were pushed to the edge of extinction by DDT.
Not quite true.
In fact, Bald Eagles and Osprey were pushed to the edge of extinction by bullets and leghold traps long before DDT showed up on the scene. See this previous post for more information about that.
This is NOT to say that the ban on DDT was not good for birds, only that the notion that Bald Eagles and Osprey were specifically driven off the map by DDT is simply not true, and obscures an important story about the value of the Bald Eagle Protection Act of 1940, and the Endangered Species Act of 1973.
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11 comments:
Darn it - the link doesn't work. And I tried a search - and it pops up with links but then gives me the ol' 404.
What about the Cornell study from November - April? Don't tell me that is bogus too - I have been having so much fun with it!
Fixed the link. Apparently, I was flying fast this morning!
No one ever said that DDT was the sole reason for the decline of populations of eagles and osprey.
However, especially after the increased protections against hunting in federal law in 1941 paved the path for recovery of eagles, they didn't come back. Why?
Bird watchers -- many in the Christmas bird count -- noticed that the young birds, juveniles and adolescents, disappeared. In contrast to bird counts prior to 1946, young birds absolutely disappeared. In those few areas where eagle and osprey counts occasionally increased, the increases stopped.
Very simply, these birds were not producing successful fledges.
DDT was the culprit. By 1962 research was clear that DDT kills birds in a number of ways. Eagles, for example, die when they get doses of DDT from the fish they eat, who got the DDT either from runoff or from the insects and other small creatures who absorbed it when it hit the water. DDT takes longer to kill adults, but a young bird fed this super-concentrated DDT would be lucky to make it past a few weeks. That explained many of the dead eaglets in the nests.
DDT kills migrating birds. The stuff concentrates in fat that is burned when the birds migrate. During migration, the birds burn the fat and the DDT comes out of solution and lodges in the brain of the bird, and the heart muscles. At certain concentrations the brain simply stops working, and the birds "forget" to eat, "forget" how to avoid power lines, and eventually hit some fatal incident. In a few cases, the DDT causes heart attacks in flight -- and the birds literally dropped from the skies.
DDT-fed mothers produced eggs with chicks laced with DDT. Chicks died in the shell, or may have hatched, but could not learn to eat, or simply had heart attacks. More dead eaglets in the nests.
Eggshell incompetence was observed at this time, but was not confirmed until the 1970s. Eggshell thinning provided a third way that DDT kills eagles. And osprey, and peregrine falcons, and brown pelicans -- all birds of prey at the top of their particular food chains.
But for the ban on using DDT in agriculture, all four of those species would be extinct in the U.S. today, if not the world.
DDT residues now plague the California Condor, which is a step past the top predator -- it's the key carrion-eater, so it gets ALL the DDT concentrated in an ecosystem.
So, the story that bald eagles, osprey, peregrine falcons, brown pelicans, bats, many songbirds, and other species, were pushed to the brink of extinction by DDT is accurate in every detail -- except, of course, details made up by people afterward. No one said DDT was the sole culprit. It was just the last big one.
Under the Endangered Species Act, by the way, recovery of the peregrines in the northeast is almost solely the result of egg relocations and wild release of captive-bred birds.
There is a great story in the Bald Eagle Protection Act, and another in the Endangered Species Act. That story includes help from the ban on DDT use on cotton crops.
I invite you to join the Christmas Bird Count with your local Audubon Chapter this year. There is much about the bird count you appear to misunderstand. Spend some time with local birders, and you can learn the facts.
Ed, I have joined the Christmas Bird Count in years past -- in fact I used to the work for National Audubon Society, so I have spent some time with the bird literature!
The observed population climb for Bald Eagles is very rapid (and sustained) with the start of the Bald Eagle Protection Act, and was NOT slowed down by the introduction of DDT (or sped up by its ban from what I can tell). The decline of Bald Eagles and Osprey to near zero occured before DDT was invented. All of this is documented fact, and National Audubon Society's own data makes this case as I note in this post.
I am not FOR DDT -- quite the opposite. Opposed to a lot of other pesticides too, as a matter of fact (see my post on Swainson's Hawk poisoning in Latin America on this blog for an example of non-DDT poisoning).
That said, the research on DDT and egg shells is NOT quite as clear as some would have the world believe. For example, with passerines (i.e. most birds), egg shells are not thinned by DDT. The initial research that showed it did thin paserine shells was a fraud done with quail that were put on a calcium-limited diet. Subsequent research never showed thinning for passerines, most of which are not eating bugs or are eating bugs that are not typically sprayed (i.e. forest canopy bugs).
Also, you should know that egg shells were getting thinner for 50 years before DDT was invented. See >> http://www.sciencenews.org/sn_arc98/4_25_98/fob2.htm
So yes, I am glad we banned DDT, but NO,it did not cause the almost total loss of Bald Eagles or Osprey, nor did the introduction of DDT slow the growth of Bald Eagles or Osprey, nor has its ban done too much that we can see to change the growth in populations (the curves are pretty steady). Look at Audubon's own Christmas Bird Count data (I provide the links) at the "Bald is Beautiful" post and note that data IS adjusted by bird/observor hour.
As for the California Condor, that species is NOT seriously plagued by DDT (anyone who tell you that is misinformed), but by lead from gut piles and garbage ingested by both chicks and adults (bottle caps, wire, nails, etc.). I have written about that on this blog too.
Ironically, the California Condor would be extinct as a species if the world had followed the National Audubon Society's advice, as NAS was adamantly opposed to captive breeding of these birds, which is what ACTUALLY brought them back from the edge of extinction. I love the National Audubon Society, but the organization has hardly been a leader on Condors.
You mention Hawk Mountain in another comment -- you might look up the TRUE history of that place and the National Auduon Society as well. Rosalie Barrow Edge, who founded Hawk Mountain, sued NAS who was NO help in creating or protecting Hawk Mountain. See >> http://www.portal.state.pa.us/portal/server.pt?open=514&objID=588354&mode=2 for a little of the interesting history here.
For the post and story about Swainson's hawks (who change their diet and habits when they migrate to South America) see >>
http://terriermandotcom.blogspot.com/2006/12/single-transmitter-made-world-of.html
For a post on why condors have been in decline for 15,000 years... and how they came back thanks to captive breeding, see >> http://terriermandotcom.blogspot.com/2006/12/condors-and-species-lost.html
For more on lead shot, garbage and condors, see
>> http://www.azgfd.gov/w_c/california_condor_lead.shtml and
>> http://blogs.discovery.com/animal_news/2009/09/condor-chick-dies-from-ingested-trash.html
All of this is documented fact, and National Audubon Society's own data makes this case as I note in this post.
I'd love to have a link to anything from the Audubon folks saying that. No such thing has ever been published in Audubon Magazine, nor in any of their other publications. Audubon has testified to the contrary in any number of hearings before Congress, and in court.
As to the condor, my sources are those with the California Condor Recovery Project. Lead shot was a big problem, and occasionally still provides serious difficulty for condors, but lead shot was banned in most of their territory years ago. What is getting them now is DDT. The eggshells are too thin to be competent, and there is serum DDT in the mothers that squares with the serum DDT levels in other birds with similar troubles.
DDT is every bit as nasty as it was made out to be. Courts ruled that was no less than four times. Since 1962, there have been more than 1,000 peer-reviewed studies supporting the claim that DDT hammers birds. If you can find a contrary study, I'd like to see it.
Ed, I see you do not know how to use the Google.
If you did (oryou would find dozens of articles about lead shot killing condors and many articles about trash killing condors.
I have supplied links (here's one >> http://www.audublog.org/?p=3845 and another one >> http://www.skinnymoose.com/hogblog/2010/02/22/lead-ban-chronicles-three-more-condors-reported-dead-from-lead/ and another one >> http://www.huffingtonpost.com/2011/06/02/california-condors-death-lead-poiso and another one >> http://ca.audubon.org/california_condor.html)
But what's the point of giving you links? You have clearly not gone to the ones already supplied, nor have you looked at the Bald Eagle data from the Christmas count from Audubon.
If you had done the *slightest* bit of research you would have found this page >> http://ca.audubon.org/birds/condor_history.php which give Audubon's history with condors (carefully leaving out the ugly parts about their opposition to captive breeding) which notes that the birds were in deep decline long before DDT, and in which the words "DDT" and "pesticides" appear nowhere, but the words "gut pile" and "lead" appear repeatedly.
Since you are too lazy to go to the links already supplied, I am now done, and so are you. Goodbye! This blog has rules, and one of them is that I do not allow time wasters.
I see you don't know how to use Google, PBurns . . .
Or, perhaps, we can leave off the insults that we know are inaccurate, and discuss the issues.
California Condors and DDT:
http://www.nytimes.com/2010/11/16/science/16condors.html
The article tells the story:
Joe Burnett, a senior wildlife biologist with the Ventana Wildlife Society and the lead biologist for the Central California condor recovery program, who had been monitoring the condor pair, was delighted with this promising development in the continuing effort to save the nation’s largest bird from extinction. When this first breeding attempt proved unsuccessful, Mr. Burnett attributed it to the young birds’ inexperience. But when he climbed the giant tree to examine the abandoned nest, he was stunned at what he uncovered: the first evidence of a potentially significant new hurdle for the condor program.
“The eggshell fragments we found appeared abnormally thin,” Mr. Burnett said. “They were so thin that we had to run tests to confirm that it was a condor egg.” The fragments reminded him of the thin-shelled eggs from birds like brown pelicans and peregrine falcons, which had been devastated by DDT but are now on the rebound.
The discovery raised a disturbing question: could DDT — the deadly pesticide that has been banned in the United States since 1972 — produce condor reproductive problems nearly four decades later?
I don't know if the stuff is even published in journals, yet. I was alerted to it by workers in the condor program several weeks before the story in the NY Times.
The Times story continues -- first one up on Google:
Once Montrose stopped discharging DDT into the sewer, that contamination source disappeared. “Brown pelicans rebounded fairly quickly after the dumping stopped,” Dr. Witting said.
James Haas, the environmental contaminants program coordinator for the Pacific Southwest region of the United States Fish and Wildlife Service, noted that other birds in the region that feed higher on the food chain, like bald eagles, continue to suffer from DDT-induced eggshell thinning.
Concerns about condors and DDT have prompted the Fish and Wildlife Service to initiate a new one-year project to study how marine mammals might be carrying Montrose DDT up the California coast. The main investigator, Myra Finkelstein at the University of California, Santa Cruz, is also leading a four-year study to investigate risk factors and management strategies to ensure the condor’s long-term sustainability. This includes not only DDT but also poisoning that comes from ingesting lead-bullet fragments found in hunter-shot game. Lead poisoning was a major factor in the bird’s brush with extinction and remains the primary danger today to released condors.
Because of the lead poisoning problem, in 2008 California enacted legislation requiring hunters in condor country to use ammunition without lead.
Despite lead poisoning and the emerging DDT challenge, Mr. Burnett remains optimistic. He is hopeful that taking steps like capping the DDT-contaminated Montrose marine sediments as well as continuing research will provide solutions. He notes that in 1982 the population of California condors had been reduced to 22 birds. Although problems remain, bringing back the condor has been a conservation success story. There are now 380 California condors in the world, with about half of these titans of the sky flying free in the Western United States.
Got citations on eagles not being threatened by DDT? I haven't found any on Google.
Central California condors are the ones in trouble, because they feed on marine mammals:
"Even today, sea lion blubber contains high levels of DDE, a toxic metabolic breakdown product of DDT."
"James Haas, the environmental contaminants program coordinator for the Pacific Southwest region of the United States Fish and Wildlife Service, noted that other birds in the region that feed higher on the food chain, like bald eagles, continue to suffer from DDT-induced eggshell thinning.
Concerns about condors and DDT have prompted the Fish and Wildlife Service to initiate a new one-year project to study how marine mammals might be carrying Montrose DDT up the California coast."
Source.
Word verification: jiveness ;~)
Luisa, the article you did not post the link to actually makes my case!
But before we get to that link, please read my post again: it talks about Bald Eagles and Osprey and it talks about Audubon's own data sets. No mention of Condors at all!
That said, go to to the links I have added in the comments regarding condors, especially this one >> http://ca.audubon.org/california_condor.html Read the entire post to get a little Condor history. Note that California Audubon makes no mention of DDT or pesticides at all, but mentions lead a half a dozen times!
OK, that out of the way (you may have already read it, in which case my apologies), let's go the condors and DDT story which makes my case.
For other readers, here's the link >> http://www.nytimes.com/2010/11/16/science/16condors.html
What's the article say in full context?
What it says is EXACTLY what I say. I quote:
"Myra Finkelstein at the University of California, Santa Cruz, is also leading a four-year study to investigate risk factors and management strategies to ensure the condor’s long-term sustainability. This includes not only DDT but also poisoning that comes from ingesting lead-bullet fragments found in hunter-shot game. Lead poisoning was a major factor in the bird’s brush with extinction and remains the primary danger today to released condors."
Yep. The condor was going extinct BEFORE DDT was even invented (see first link for that story) and lead poisoning is the PRIMARY problem (being shot by rifles and ingestion of bullets and shot from gut piles) along with trash consumption to this day, as I note.
So what's the DDT and DDE story wiht condors here and why does is actually SUPPORT my point about Bald Eagles and Osprey?
Simple: This article is not about a GENERALIZED DDT problem with condors. It says there isn't one. It says there MAY be a SPECIFIC DDT problem with a Super Fund site where they actually manufactured the pesticide for many decades. And even here, the DDT and DDE link is speculative, and all they are going to do is look for it.
Bottom Line: What caused the demise of the Bald Eagle and the Osprey (and the Condor too) was NOT DDT, but bullets and leghold traps, and the banning of DDT was NOT the main player in bringing these birds back from the edge, nor is it a major factor in their health today. Today, Bald Eagle and Osprey populations are soaring all over. Condor populations, of course, have been on the decline for 15,000 years as I note here >> http://terriermandotcom.blogspot.com/2006/12/condors-and-species-lost.html but they too are slowly coming back and expanding their range a bit.
Please note that I have NEVER said that DDT did nothing to raptors and scavenger, I have NEVER said that it did not thin egg shells, and I am NOT advocating the return of DDT, What I HAVE said, and what is entirely true, is that most passerine birds were not effected from DDT (most are seed-eaters), many of the top-end predators like Bald Eagles, Osprey and Condors had their populations knocked flat long before DDT showed up (true for most American wildlife of all kinds) and, in the case of the Bald Eagle, the Golden Eagle and the Condor, the turn around in their fortunes cannot be traced to a ban on DDT (though it no doubt helped), but to very specific protection legislation and programs. All of that is TRUE and the article you cite and I link to actually makes that case.
By the way, anyone who wants to read what REALLY happened to the Bald Eagle only has to go to the Bald Eagle Information cite, which note that the bird was so devasted by 1940 (before DDT was even introduced!) that we had federal legislation to protect it: http://www.baldeagleinfo.com/eagle/eagle11.html
"Before European settlers first sailed to America's shores, bald eagles may have numbered half a million. They existed along the Atlantic from Labrador to the tip of south Florida, and along the Pacific from Baja California to Alaska. They inhabited every large river and concentration of lakes within North America. They nested in forty-five of the lower forty-eight states. One researcher estimated an eagle nest for every mile of shore along Chesapeake Bay. They congregated on the lower Hudson, and were extremely abundant along the coast of Maine.
There is no single cause for the decline in the bald eagle population. When Europeans first arrived on this continent, bald eagles were fairly common. As the human population grew, the eagle population declined. The food supplies for eagles decreased, because the people hunted and fished over a broad area. Essentially, eagles and humans competed for the same food, and humans, with weapons at their disposal, had the advantage. As the human population expanded westward, the natural habitat of the eagles was destroyed, leaving them fewer places to nest and hunt, which caused the population of bald eagles to decline sharply by the late 1800s. By the 1930s, people became aware of the diminishing bald eagle population, and in 1940 the Bald Eagle Act was passed. This reduced the harassment by humans, and eagle populations began to recover."
The same source does note that DDT caused egg shell thinning and infecundity (no denying that), but does not mention the fact that even when DDT was in play, the bald eagle population soared upwards -- a trajectory it maintained during the spraying of DDT and which did not soar higher in vector after DDT was banned.
At the bottom of the same link they list the seven causes of death to bald eagles today: bullets, electrocution, lead poisoning, poison, collisions with vehicle, starvation, fishing line and lures. Pesticides is not mentioned at all.
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