We’re pretty careful about the acronyms we use on this blog – but DDT needs no introduction. The pesticide (officially called dichlorodiphenyltrichloroethane) came into common use after the Second World War because it was great at killing the insects that ruin crops and spread disease. Unfortunately, it was bad news for more than just bugs. After it was linked to health problems for humans and many other species, its use was banned in the 1970s.
Photo credit: Gordon Court.
It’s been more than 30 years since then – but some species in Alberta are still recovering. One of these is the peregrine falcon. In the early 1970s, our initial surveys of the peregrine population showed a steady and drastic decline, mainly due to earlier DDT use. Unless something changed – and soon – we feared we would lose the species entirely in Alberta.
So we took emergency measures to prevent that from happening. First, young birds from the very last pairs of peregrines in southern Canada were brought into captivity and placed in a federal breeding facility in Camp Wainwright, Alberta. Eventually, this program produced enough falcons for us to attempt re-introducing the species in the wild. This has gone well: surveys conducted in 1995-2010 have documented pairs of peregrines returning to nest at sites on the North Saskatchewan, Peace, Slave, Red Deer, and Brazeau Rivers.
For the past three summers, we’ve released captive-raised young near the Pembina River, where peregrines haven’t nested for decades. This project has truly been a team effort – supported by funds from Transalta Utilities; Capital Power; and the Alberta Sport, Recreation, Parks and Wildlife Foundation (ASRPW) as well as the government of Alberta. We also received logistic support from the Alberta Conservation Association and Pembina River Provincial Park. These new additions increase the breeding pool, helping the population grow faster.
This May, all of our hard work paid off. Biologists discovered a pair of peregrine falcons nesting on the banks of the Pembina – the first to do so in exactly 50 years. Although the species is still officially designated as threatened, things are definitely looking up.
This summer marks the first time peregrines have nested on the Pembina River in half a century. Photo credit: Gordon Court.
In 2015, we’ll conduct a province-wide survey to assess the status of the peregrine falcon. If we have at least 70 nesting pairs of birds, the species may be removed from the Threatened Species list. At any rate, these birds are on track to continue reclaiming their place in Alberta’s ecosystems – and we’re happy to welcome them back.