Paper again wrongly asserts raptor populations controlled by DDT

Shooting, egg collection and falconry along with habitat alteration certainly did raptors no good but DDT is not now nor ever was guilty of causing raptor decline, yet still one of the greens’ most successful myths is constantly reiterated and reinforced

You’d think the occasional reporter would check the numbers, raptors declined prior to and began their recovery subsequent to the introduction of DDT. If you had to assume something from the actual data it would be that DDT use encourages raptor populations, not the other way ’round.

DDT ban leads to resurgence in numbers of birds of prey
BY TOM SPEARS, THE OTTAWA CITIZEN FEBRUARY 6, 2012 10:06 PM

Denis Lepage was walking by Lake Erie a few weeks back when he saw some open water in a frozen bay, and about 25 bald eagles grouped around it.

The eagles were lunching on fish, ducks and coots. And their numbers reminded the bird scientist just how well birds of prey are recovering from their former sharp loss of numbers.

Across North America, the trend among hawks, eagles and other raptors is generally upward. A major cause is the ban on DDT, which caused the birds to lay eggs with shells prone to cracking open.

The continuing trend has been a big relief to biologists and bird-lovers.

“There was a very big recovery for a lot of species,” said Lepage, who works at Bird Studies Canada in Port Rowan, Ont. “Some of the species have stabilized, others still seem to be increasing.

“Bald eagles in the Great Lakes area are becoming very common.”

Eagles love to nest on big nuclear stations, which mimic cliffs near the water’s edge.

Bird Studies Canada is a national conservation group. Together with American partners it produced the report based on bird counts at 48 sites.

The red-shouldered hawk, once in steep decline, is doing better today. So is the peregrine falcon, which often nests on high-rise buildings in Ottawa.

The study also charts the eye-catching spread of the turkey vulture. Once a purely southern bird, it moved into southern Ontario in the 1970s and is now common — and still increasing by seven per cent a year — in rural areas across much of Ontario and Quebec.

An exception is the American kestrel, once called the sparrow hawk, a starling-sized member of the falcon family that eats mice in farm fields. It’s in sharp decline for uncertain reasons.

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8 responses to “Paper again wrongly asserts raptor populations controlled by DDT

  1. Don’t worry. Wind turbines will eliminate those nasty raptors.

  2. Wrong, I did a review paper on DDT and the science was very conclusive!

    • William Nuesslein

      Conclusive of what? DDT was eliminated decades ago. Why was the benefit delayed so much. Birds like just about every other type of living creature has reproductive capacity to compensate for disasters. Look how humans repopulated San Fransico after the 1906 Earthquake.

      • Because DDT doesn’t go away quickly and was still concentrating up the good chain! It would require decades for the DDT to work it’s way up and out of the food chain! At the peak of DDT use, there were mosquito fish in the Mississippi river with such high concentrations in their bodies that they were lethal to their predators!

  3. GreggM
    I would like to see that informaion.

    • The paper I did was during the 70’s for a class and I used about 200 peer reviewed references. It will be hard to get due to time.

  4. Is this website for real? A website that claims to debunk junk science, yet offers no sources on why DDT does not affect raptors. Instead, asserts that DDT encourages raptor populations with no sources. You don’t even need a source for that, just common sense. How could pesticides, which eliminate a part of the food chain, encourage raptors, which are apex predators? You guys are a joke.

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