SOUTH PADRE ISLAND, Texas (ValleyCentral) — Sunrise over South Padre Island is always special, but each spring and fall the opening of the day promises something extraordinary.

The biannual migration of peregrine falcons along shores of South Padre represents one of the most remarkable migratory marvels on earth, and the peak of fall migration is underway right now with peregrines traversing more than 8,000 miles on their journey.

For nearly a half-century, biologists like Greg Doney, project leader with Earth Span, have been monitoring the biannual migration along South Padre capturing, sampling, banding and releasing some 11,000 Tundra Peregrines in one of the longest running migration studies on Earth.

“We are in our 47th year of the Padre Island Peregrine falcon survey,” Doney said.

The Peregrine falcon almost vanished due to the harmful pesticide DDT, but with banning of DDT in 1972 peregrines have rebounded dramatically and in 1999 were removed form the endangered species list.

The undeveloped stretch of beach and wind tidal flats stretching some 25 miles north of the town of South Padre Island is perhaps the most important site in the western hemisphere for Peregrine falcons hunting avian prey during migration from breeding grounds in the arctic to wintering habitat in South America.

The men and women who have been monitoring peregrines over decades share a special admiration for the falcons and an acute awareness of how vital South Padre is to the continued recovery of these intrepid travelers.

Biologist Tom Machetle, who passed away in 2016, worked with Padre peregrines for many years and shared a deep appreciation for the falcons and their unique island.

“I think it is just the jewel of the Gulf Coast largely because of this stretch that is uninhabited by humans and used recreationally. I think that is the key thing,” he said.

Raptor researcher Hana Weaver with the Peregrine Fund holds a three-month-old female falcon that has already flown some 3,000 miles from her nest site and may migrate as far as South America.

“Incredible hunters, incredible aerial flyers…stunning birds…perfect in every way,” she said.