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.