The Baxter’s Pinnacle peregrines experienced little to no human interruption during their incubation and chick-rearing phases thanks to active support from the park’s two authorized concessioners for guided climbing services, and to the cooperation of Jackson Hole’s climbing community that demonstrated responsible behavior and respected the closure. Peregrines are cliff nesters and can be sensitive to human disturbance, especially during their nesting period. Falcons are quite territorial and will often abandon nests to defend their territory, which leads to nest failure and low reproductive success.
Decimated by the harmful effects of the pesticide DDT, it is believed that peregrine falcons were virtually eliminated from the Greater Yellowstone Ecosystem (GYE) by the 1960s. In 1980, efforts to reintroduce peregrine falcons to Grand Teton National Park were initiated in conjunction with similar efforts elsewhere in the GYE and western United States. Between 1980 and 1986, 52 fledgling falcons were released at several sites in the Teton Range; seven to eight birds were released each time. After sufficient recovery was achieved, peregrines were delisted from the endangered species list in 1999. However, peregrine falcons remain a species of concern in Grand Teton National Park where only four nesting pairs exist. The Baxter’s nest area was first discovered in 2010, and it has produced one chick in three of the last four years (2010, 2011, and 2013). One other Teton site fledged two chicks this year.
The public closure served a second purpose: to also protect climbers from the peregrines as they will defend their nest site by dive-bombing perceived intruders. The peregrine falcon is among the world’s fastest birds, flying at 40-55 mph and diving at more than 200 mph while defending a territory or striking prey. This posed a safety risk to climbers who may have been knocked off their rock ‘perch’ and injured.
Seasonal and temporary closures for wildlife protection are common in Grand Teton to protect both wildlife and park users. Entering a posted wildlife closure is a violation that can result in a citation and fine under the code of federal regulations.