CHICAGO, USA (AP) — In the early 1950s, there were no peregrine falcons in Illinois and scientists worried that the species would disappear entirely from North America.

But officials with the Chicago Peregrine Programme announced yesterday that the quick-diving birds are flourishing in Illinois and are no longer in immediate danger.

Over the years, the peregrine falcon’s status has improved from endangered to threatened. Now the species has been removed from the state’s endangered and threatened list but is still protected under the federal Migratory Bird Treaty Act, officials said.

Mary Hennen, director of the Chicago Peregrine Programme, leads the 30-year-old conservation effort operated out of the Field Museum and its team in reintroducing, tracking and researching the birds.

“We’re thrilled that peregrines are doing so well, but the journey’s far from over. Now that they’re off the threatened list, in some ways, we need to work harder to make sure that they’re doing OK,” she said.

At one point, Illinois shared about 50 pairs of peregrine falcons with the entire Midwest. Now the state has 29 nesting territories, known locations holding one or two birds, 20 of which are in the city, according to the Chicago Peregrine Programme.