Audubon Christmas Bird Count issue: Eagles did not prosper during the ‘time of DDT’

August 26, 2015

Still photo captured from the film,

Still photo captured from the film, “Christmas Bird Count,” by Chan Robbins; photo shows a group counting birds, probably in the 1940s or 1950s. Audubon’s Christmas Bird Count got its start in 1900.

In the notoriously wrong and misleading “100 things you should know about DDT” posted by pro-DDT, anti-wildlife Steven Milloy of “Competitive Enterprise Institute” and Fox News fame, based on the foggy rant of Dr. Gordon Edwards, we get these two misleading claims:

69. After 15 years of heavy and widespread usage of DDT, Audubon Society ornithologists counted 25 percent more eagles per observer in 1960 than during the pre-DDT 1941 bird census. [Marvin, PH. 1964 Birds on the rise. Bull Entomol Soc Amer 10(3):184-186; Wurster, CF. 1969 Congressional Record S4599, May 5, 1969; Anon. 1942. The 42nd Annual Christmas Bird Census. Audubon Magazine 44:1-75 (Jan/Feb 1942; Cruickshank, AD (Editor). 1961. The 61st Annual Christmas Bird Census. Audubon Field Notes 15(2):84-300; White-Stevens, R.. 1972. Statistical analyses of Audubon Christmas Bird censuses. Letter to New York Times, August 15, 1972]

99. The Audubon Society’s annual bird census in 1960 reported that at least 26 kinds of birds became more numerous during 1941 – 1960. [See Anon. 1942. The 42nd annual Christmas bird census.” Audubon Magazine 44;1-75 (Jan/Feb 1942), and Cruicjshank, AD (editor) 1961. The 61st annual Christmas bird census. Audubon Field Notes 15(2); 84-300]

100. Statistical analysis of the Audubon data bore out the perceived increases. [White-Stevens, R. 1972. Statistical analyses of Audubon Christmas bird censuses. Letter to New York Times, August 15, 1972]

Those claims are false with regard to bald eagles.

The careful citations offered by Milloy and Edwards simply do not exist; if the source exists, the source does not say what is claimed by these guys.  (Don’t take my word for it; go see for yourself.)

Audubon never suggested, in any forum, that their famous Christmas Bird Count had shown increases in eagles. Most other species showed no increases, either. I spent a couple of days at the library of Southern Methodist University reviewing every issue of Audubon Magazine from 1941 through 1974, and found not a single article suggesting anything other than declining eagle populations in the lower 48 states (Alaska eagles were not untouched by DDT, but were not so seriously affected; and as you will see below, the first counts of Alaska’s eagles did not occur until after 1950, so the addition of numbers from Alaska counts do not indicate an increase in U.S. population of eagles.)

I also reviewed each bird count, usually published in a separate booklet with the March issue of Audubon in that time. While raw numbers increased, that was clearly due to increases in people observing. At no point did any ornithologist or Audubon member suggest eagles were in recovery, from 1941 through 1972.

That’s a long explanation, unsuitable for quick discussion on blogs, and wholly too much for a 140-character Tweet. My experience with Milloy and his followers is that they will say my analysis somehow errs, though they cannot offer any real analysis from any other source that isn’t just a misreading of the raw bird count.

I wrote the Audubon Society, and asked them to respond to the claim. At first the press office thought the claims so bizarre that they didn’t think a reply necessary.  I sent them a half-dozen links to other documents that cited Milloy and Edwards.  Delta Willis at Audubon took the claims to officials of the bird count.

Geoff LeBaron, Director of Audubon’s Christmas Bird Count sent the following reply (posted without correction).

See also the footnote from Audubon Chief Scientist Gary Langham appended to the end of the e-mail.

LeBaron, Geoff
Sent: Friday, May 10, 2013 10:21 AM
To: Willis, Delta; Langham, Gary; Dale, Kathy
Subject: RE: DDT and effects on birds, and Audubon Christmas bird count

Hello Delta,

From the 1930s through 1970s there was a tremendous growth in the number of Christmas Bird Counts, from 203 total counts in the 30th CBC to 1320 counts in 80th CBC.  The number of observers on those counts rose from 679 in 30th to 32,322 in the 80th Count.  That is a tremendous increase in effort as well as geographic coverage, and more people in more areas are going to count more Bald Eagles, even if the populations are [were] declining.

A second major factor is that during that period many CBCs were started with the specific goal of censusing wintering Bald Eagles.  Thus we were targeting the areas where eagles were wintering, and thus tallying a much greater percentage of the total population.

Thirdly, there were only two individual CBCs conducted in Alaska prior to the late 1950s.  Bald Eagle populations never suffered dramatically in Alaska [from DDT?], and their numbers were always much higher there.  Since the late 1950s there has been a tremendous growth in the number of counts in Alaska—again, with some of these counts targeting areas where wintering eagles congregate even in the thousands.  These counts added in Alaska can contribute greatly to the total number of Bald Eagles in each season’s CBC.

Thus even while Bald Eagle populations were plummeting in the lower 48 states (outside of Florida) CBC [Citizen Science] efforts were greatly increasing, and in fact targeting monitoring Bald Eagles.  That is why both the raw number of eagles and the numbers when weighted for observer effort went up when you pull CBC data for Bald Eagle during the decades of heavy DDT use.

It’s still educational to look at raptor numbers in CBC data in the years following the banning of the use of DDT in the US.  Many species of raptors show a rapid rebound in numbers after the mid-1970s…and Bald Eagles also dramatically increased.

Per Dr. Gary Langham, Audubon Chief Scientist:   Audubon scientists are careful to include levels of participation and geographic coverage in all analyses. Fortunately, we have tracked both of these aspects since the CBC was started and so it is straightforward to adjust for their impacts.

Bird counts do not show that eagles were out of trouble during DDT years, roughly 1946 through 1972; especially they do not show that bald eagle populations increased.

More:

Explanation of the Christmas Bird Count in four minutes, by Chan Robbins.

Chandler Robbins, founder of the Audubon Christimas Bird Count, screen capture from Audubon film

Chandler Robbins, founder of the Audubon Christimas Bird Count, screen capture from Audubon film “Christmas Bird Count.”

Nota bene: Yes, this has sat in my “to be published” box for too long. It was scheduled for publication, but it appears I had not hit the “publish at scheduled time” button. My apologies to readers, and especially to Audubon’s scientists and press people.


Annals of DDT: Interior Dept compliments Rachel Carson’s research in Silent Spring

October 17, 2010

One of the most frequent hoax charges against Rachel Carson claims that she didn’t base Silent Spring on research.  Greater hoaxers claim that there is little or no evidence of harm to birds from DDT.

Rachel Carson's book stirs controversy, newspaper headlines

Rachel Carson's book stirred controversy, as shown in newspaper headlines

These critics forget history, or they try to cover it up so you won’t know any better.  Carson provided more than 50 pages of citations to peer-reviewed research and communications with leading scientists in ornithology and chemistry about DDT and the damage it does.

Carson’s deep research won acknowledgment from the U.S. Department of the Interior, in this 1962 speech before the Audubon Society meeting in Corpus Christi, Texas, by the Special Assistant Assistant Secretary for Fish and Wildlife Robert M. Paul.

Paul told the birders that Interior was proud of the fact that so much of the research in the book relied on Interior’s research, from the U.S. Fish and Wildlife Service:

In addition, we are proud that so much of ‘Silent Spring“ is based on Fish and Wildlife Service research. And, with no modesty at all, we like to point out that Miss Carson is nobly carrying on a tradition that employees of the Department of the Interior, beginning with Walt Whitman nearly a century ago, have written some of the Nation’s most important books.

That’s quite the compliment to Carson, being compared even distantly to Walt Whitman.  It’s also a helluva brag for USFWS.

It’s also a 30-second response to the false charge that Carson’s work was not research based, or that research did not show DDT damage to wildlife.

Paul spoke to the Audubon Society about work to set up and operate the Federal Pest Control Board.

A .pdf of the speech can be found at the website for Interior, in a compilation of information from Interior about DDT between 1945 and 1998.  Full text below the fold.

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Can’t fool the birds: Migratory birds in North America react to climatic warming

February 12, 2009

Generally it would be an insult to call someone a bird brain.  We may need to revise that thinking.  In contrast to climate change denialists, 177 species of migratory birds in North America have adjusted their migrations because of a warming climate.  The birds know something the denialists don’t.

The news comes from the National Audubon Society, after analysis of 40 years of bird count data.

Migrations has the story, along with the map that is appearing in U.S. newspapers this week.  Cornell University’s ornithology blog, Round Robin, provides history to the study and a couple more links to science reports.

How will denialists spin this?  It’s difficult for them to claim that the birds have been hornswoggled by inaccurate newspaper accounts, since these are not the birds whose cages are lined with newspapers.

Eastern Meadowlark, photo by FWS/John and Karen Hollingsworth

Eastern Meadowlark, photo by FWS/John and Karen Hollingsworth

We don’t have a canary in a mine warning us, this time.  It’s the meadowlark on the prairie. Will we listen, in time?

Eastern and Western Meadowlark: These popular robin-sized grassland birds form winter flocks and always feed on the ground. Neither species has been wintering farther north over the past 40 years, probably because the quality of northern grasslands is not sufficient to support these birds through the winter. The Eastern Meadowlark is one of Audubon’s Common Birds in Decline; its population has plummeted 72% in population over the last 40 years.

Also see this earlier post, “Plants refuse to listen to climate change skeptics.”


The $7 million dogwood blossom

April 29, 2008

Not perfect — there is a brown spot on it; but beautiful, surpassingly rare, a creature of the serendipity of nature, it is a natural dogwood blossom in Dallas County, Texas:

Dogwood blossom in Dogwood Canyon, Texas

What we came to see – the magical dogwood blossoms.

On April 5 Kathryn and I joined David Hurt and a jovial band of hikers for a trip into Dogwood Canyon in Cedar Hill, Texas. The physical formation of Cedar Hill upon which the city of the same name and several others stand, is one of the highest spots between the Mississippi River and the Rocky Mountains. It is an outcropping of chalk, a formation known as the Austin Chalk, that runs from Austin, north nearly to the Oklahoma border.

This rock formation creates a clear physical marker of the boundary between East and West. Dallas is east of the line, Fort Worth, Gateway to the Old West, is 30 miles farther west. On this outcropping is married the plains of the west with the oaks and forests of the east. Within a few miles of the line, the botanical landscape changes, cowboy prairie lands one way, forest lands the other.

On the chalk itself, the soil is thin and alkaline. The alkalinity is a function of the chemical composition of the chalk underneath it.

Dogwoods love the forests of East Texas with their acidic soils. Early spring produces fireworks-like bursts of white dogwood blossoms in the understory of East Texas forests. Dogwoods die out well east of Dallas as the soil changes acidity; driving from Dallas one can count on 30 to 60 miles before finding a dogwood.

Except in Dogwood Canyon. There, where entrepreneur David Hurt originally planned to build a family hideout and getaway, he found a stand of dogwoods defying botanists and the Department of Agriculture’s plant zone maps, blooming furiously in thin alkaline soil atop the Austin Chalk.

(continued below the fold)

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