Staff at Devils Tower National Monument are closely monitoring peregrine falcons near the Tower. Although peregrine falcon behavior early in the season was consistent with courtship and breeding, biologists have determined that the pair on Devils Tower did not have a successful nest this year.  Cold, wet weather late in the spring can cause peregrine falcon nests to fail.  “Falcons nest on rock ledges high on the Tower, in areas with very limited shelter.  This year’s late-season snow, colder than normal temperatures, and frequent hard rains have made it very difficult for them,” said Rene Ohms, Chief of Resource Management.  

Each spring, one area of the Tower is temporarily closed to rock climbing, to give the birds an undisturbed area to select a nest site.  If the falcons select a nest on a different face of the Tower, the closure area is then moved. Climbing near a nest site can be distressing to parent birds and endanger chicks, and climbers can be injured when falcons aggressively dive to defend their nest. The climbing closures are an annual occurrence established under the monument’s 1995 Climbing Management Plan, with authority from the Migratory Bird Treaty Act.

Peregrine Falcons experienced sharp population declines in the 1960s and 1970s, primarily due to widespread use of the insecticide DDT.  Peregrine falcons, listed as endangered in 1970, made a remarkable recovery and were removed from the endangered species list in 1999.  Peregrines returned to Devils Tower in 2013, and have had successful nests on the Tower for the last six years. The falcons have been observed on Devils Tower this year, but their behavior indicates that they did not successfully nest. Therefore, all climbing routes on the Tower are  open.

Park staff will continue to closely observe the birds, and ask that climbers report any defensive behavior. Conditions may change at any time, and if needed a new closure may be implemented for the protection of the falcons.

Separate from the falcon closure, there is also a voluntary climbing closure of all routes on Devils Tower for the month of June. June is an important time for many American Indians, and ceremonies often occur around the summer solstice.  Climbers are asked to voluntarily respect this culturally significant closure, and to climb during other months.

Source: NPS