CASPER, Wyo. (AP) — For the first time in seven years, peregrine falcons at Devils Tower in northeast Wyoming did not have a successful nesting season.

The Casper Star-Tribune reports a pair of falcons showed behavior consistent with courtship, but the weather might have put a damper on breeding.

Rene Ohms, chief of resource management for the National Park Service, says this year's late-season snow, colder than normal temperatures and frequently heavy rain have made it "very difficult for them."

The species was listed as endangered in 1970 but had a remarkable recovery and was removed from the list in 1999. Falcons returned to Devils Tower in 2013 and successfully nested for the last six years.

Ohms says nests sometimes fail, but the population as a whole won't be affected.