One of the world’s most accomplished aerial acrobats may be making its comeback at Lake Tahoe.For the first time in decades, active peregrine falcon nests have been discovered in the Lake Tahoe Basin.Two active nests, with indications of a third, were found in the basin in 2011, according to data from the Tahoe Regional Planning Agency. Surveys in 2009 and 2010 each found one active nest.The migratory bird of prey has been sighted on occasion near Lake Tahoe in recent years, but the discoveries of the nests may be the first of their kind in about 70 years, said Shay Zanetti, a wildlife biologist with the U.S. Forest Service’s Lake Tahoe Basin Management Unit.“We have some old historic information that they haven’t been known to nest here since the ’40s,” Zanetti said.Formal surveys for the birds have only been conducted sporadically during the past two decades because the basin does not contain ideal nesting habitat. In the mid-1980s, several juvenile birds were reintroduced to the basin, but they left or were killed in the same year.Due to the lack of consistent information on the bird, it is unclear whether the increase in nests during the 2011 count represents a trend, according to the TRPA data.But the return of the species to Lake Tahoe is part of a larger recovery of the peregrine falcon, which declined rapidly in the early 1900s, dropping to just two nesting pairs in California in 1970.The drop in peregrine numbers has been attributed to the widespread use of the insecticide DDT, which accumulated in the birds and caused the falcon’s eggshells to weaken and break before they were ready to hatch.Although DDT is still being used in some countries, the recovery of the birds has been a linked to the ban on the use DDT in the United States and elsewhere.The bird is found on all continents except Antarctica, according to the U.S. Fish and Wildlife Service. Today, there are between 2,000 and 3,000 breeding pairs in Canada, Mexico and the U.S., with about 250 nesting pairs in California and 50 to 60 in Nevada.The species was taken off the federal endangered species list in 1999 and California’s endangered list in 2009, and has been heralded as an environmental success story. Peregrines are still protected under the Migratory Bird Treaty Act.Both nests located in the Lake Tahoe Basin in 2011 were located at the South Shore. The birds favor the Luther Pass area and Castle Rock near Kingsbury Grade, Zanetti said. Peregrines can be seen in the area from early April to early September.And the birds have been known to put on a show. The bird is the fastest on record, reaching speeds of more than 60 mph during level flight and almost 200 mph when diving for prey, according to the Nevada Department of Wildlife.Nesting pairs, which mate for life, have also been seen passing prey mid-air, Zanetti said.“They are incredible aerial acrobats,” Zanetti said. “That’s what they are really known for.”Rock climbers can present a concern for the cliff-nesting species, which is sensitive to disturbance. But area climbers have been helpful in reporting the presence of the birds and giving them the space they need, Zanetti said.Binoculars or a spotting scope are the best ways to catch a glimpse of this once-endangered bird making its return to the skies, Zanetti said.— The Associated Press contributed to this report.