On Monday, September 16, 2013, the Arizona Daily Star printed a story headlined: “Study: Rare Condors Harmed by DDT.” This was part of an Associated Press (AP) story. See the Star’s version here.
The trouble with the Star’s version of the story is that they left out some important details that were present in the AP story. Here is what the Star left out:
The study’s authors and other experts agree that lead ammunition, not DDT, is the main threat to the survivability of condors. But Jesse Grantham, a former condor program coordinator for Fish and Wildlife, who did not participate in the study, called the paper’s findings helpful scientific evidence that will add to the overall picture of threats facing condor recovery.
Another former condor program manager, Noel Snyder, was critical of the DDT study, however.
He said it only looks closely at one potential cause of reproductive problems — DDT — and fails to properly evaluate the potential effects of other contaminants and factors that may be involved and more important.
“DDT is not the only thing that causes eggshell thinning, and the authors of the paper don’t present a significant correlation of DDT with the thinning found, and thus do not do a convincing job of linking DDT with the happenings in Big Sur.”
Study author and Ventana wildlife biologist Joe Burnett defended the team’s work, saying all data pointed to the pesticide as the problem.
“We collected data on many different environmental toxins but none, other than DDE [a daughter product of DDT], were even in the ballpark known to cause reproductive failure in birds,” Burnett said.
In the final analysis, the study’s authors say the DDT problem will fade over time.
“Like bald eagles and other bird species previously affected by DDT, the thickness of condor eggshells should recover as contamination declines in the coastal environment,” said co-author Robert Risebrough, an expert on the effects of DDT on birds.
Note that insufficient calcium in the diet also leads to egg shell thinning.
As Mark Twain wrote: “If you don’t read the newspapers you are uniformed; if you do read the newspapers, you are misinformed” – especially if you read the Arizona Daily Star.