Return of the Peregrine
Residents of the Peace get up close with a peregrine falcon and
learn about its impressive recovery
These acrobats of the air once dove and dodged across the skies
of northern Alberta – in fact, all across North America, Europe
and Asia. But the peregrine falcon couldn’t dodge the near
collapse that came with the introduction of DDT in the late
1940s.
DDT, a broad spectrum organochloride insecticide, interferes
with the reproductive ability of female birds and with the build
up of calcium in egg shells. Because the peregrine feeds mainly
on birds, which eat insects or seeds coated with DDT,
accumulations of the toxin were amplified in the peregrine. Eggs
would crack or wouldn’t hatch, cutting off the vital reproductive
link in their survival as a species.
At its lowest point, numbers of this graceful and tenacious bird
of prey in North America were estimated at around 700 birds,
down from 7000 only thirty years prior.
With the banning of DDT in Canada in 1969 and in the U.S. in 1972, the northern variety of the
peregrine falcon, known as Anatum, has made a recovery. It was downlisted to threatened in
2000.
Ursula Banasch, a wildlife
biologist with the Canadian
Wildlife Service, has been
part that recovery. She and
other biologists were part of
the breeding program for
the peregrine falcon at
Wainwright, where captive
young were raised for
release into the wild for
about 25 years.
Banasch was in Peace River
in early April with a special
visitor - Poncho, a four year
old male Anatum peregrine
falcon.
Their sessions with students and the public, hosted by the Boreal Forest Research Centre, gave
residents a clearer sense of why this bird is a key indicator of environmental health - through a
phenomenon known as “biological amplification”.
When a chemical is released into the environment and enters the food pyramid, those species at
the top of the pyramid experience an accumulation of the chemical. The effects are also amplified,
ill or otherwise.
In Europe, the peregrine falcon has also recovered. Scientists there contend that while DDT
played a role, so did two closely related organochlorides called aldrin and dieldrin. These toxins
have been severely restricted.
In western Canada, the recovery of the peregrine falcon has been so successful that the breeding
program at Wainwright was shut down in 1996. Between 1994 and 1996, nest sites for captive-
raised young were established in Alberta and Ontario. Since then, nesting sites have been
established in Quebec, the Maritimes and the Okanagan Valley.
Since 1977, over 4000 peregrines have been released in North America.
Monitoring by the Canadian Wildlife Service continues with banding and satellite telemetry.
At their session at Glenmary High School, students were more interested in Poncho and his
hungry screech. They learned that the peregrine falcon is the fastest animal ever recorded. In a
dive, this aerial predator can reach speeds up to 320 k/hr.
It made a big difference, having something to look at, said one student.
“When (Banasch) talks about something, you can always look at the bird and remember. Like
when she was talking about how fast it dives, you can see its size and shape,” said Shannon
Brown, a grade 11 student at Glenmary.
Students at Peace River High also got a visit from Poncho, who met with the public later that
evening.
They also learned that the peregrine is very adaptable. Because they don’t build their own nests
(peregrine nests are often associated with cliffs) and will go where ever there’s food, nesting pairs
have adopted some busy settings to raise young. There about four pairs on the Telus building in
Edmonton, and cities such as Calgary, New York, Winnipeg and Toronto have their own
breeding pairs, where pigeons are the favoured prey.
Banasch estimates there are probably 40 to 50 pairs in Alberta. If you want to see a peregrine
falcon, wetlands are a favoured habitat, where terns, shorebirds and even flickers are the prey of
choice. They’re also a bird of the forest, where their agility in the air is an asset.
While no nesting sites are known in the north Peace, an observant birder may see them as they
migrate through in the spring and fall.
“You’ll likely see them then, around wetlands,” says Banasch.
Learn more about the peregrine falcon at Environment Canada’s website at
www.speciesatrisk.gc.ca or the Canadian Peregrine Foundation website at www.peregrinefoundation.ca