Once teetering on the brink of extinction, the peregrine falcon is now a conservation success symbol and fast-flying proof that at-risk species *can *recover if we do it right.

© Ola Jennersten / WWF-Sweden

Nowadays, it’s fairly common to witness a peregrine falcon diving amid Toronto skyscrapers, scooping up a snack on a Nova Scotian seacoast or riding the winds across a Manitoba prairie — but the sight of this raptor was once a rarity.

These iconic birds of prey faced population collapse in the mid-20th century, largely due to the widespread use of the pesticide DDT. As predators, peregrine falcons feed mostly on other, smaller birds. But when those birds eat insects and plants that have been exposed to DDT, the concentrations of the pesticide — while small in, say, a single worm — build up as they move up the food chain.

A peregrine falcon incubates eggs, Nunavut. © Gordon COURT / WWF-Canada

DDT accumulated in peregrines so much that it disrupted their reproductive systems, causing their eggshells to thin and severely impacted their population numbers as a result. In 1955, the last wild nesting pair of peregrines was documented in Nova Scotia. A decade later, they’d completely disappeared from Ontario. By 1970, there were just three breeding pairs left in Alberta.

Identifying the threat posed by DDT, North America began restricting its use in the 1970s and had fully phased it out by 1990. By then, however, peregrine numbers were already critically low, prompting more targeted recovery efforts like captive breeding programs that then released peregrines back into their natural habitats.

These collective efforts have seen peregrines fly away from their endangered species status. They are now considered “Not at Risk” by COSEWIC and of “Least Concern” on the IUCN Red List. It’s a success story that shows us that at-risk species recovery in the face of dramatic decline *is *possible — only when on-the-ground conservation solutions can build on the momentum of meaningful policy change.