Raptor Time in the Treasure Valley

By Bruce Haak, Regional Wildlife Biologist, IDFG, Southwest Region Among the current harbingers of spring in the Treasure Valley are the noisy vocalizations and aerial "top gun" displays put on by wild peregrine falcons in both downtown Boise and at the Amalgamated Sugar Company plant in Nampa. For the past three years, a pair of falcons successfully nested on the One Capital Center building in downtown Boise, while successive pairs of peregrines have occupied the Nampa site for more than 16 years. It was recently discovered that one of the Boise birds has disappeared. It was replaced almost immediately by a juvenile falcon, so there remains only the slimmest of chances that these falcons will successfully produce young this year. In general, peregrines must be three years of age to be sexually mature. The return of the peregrine to Idaho and across the North American continent is one of wildlife management's biggest success stories. Only quick action saved the peregrine from disappearing entirely from the United States. A History Lesson The drop in peregrine numbers was first noted in the 1950s, and continued on a fast track in the years that followed. By 1973, the peregrine falcon was essentially extirpated as a breeding bird from the lower 48 U.S. states. At the time, there were less than 40 nesting pairs known in the entire country. It was this population catastrophe that led to special legal protection for peregrines under the newly formed Endangered Species Act. Nesting peregrines were gone from Idaho after 1975. The demise of the peregrine both here and in Europe was largely the result of DDT pollution throughout its environment. Ten years later, after the cessation of DDT use in this country (1972) and the release of captive-bred young, peregrines had returned to breed in Idaho. Initially, captive-bred falcons, produced at The Peregrine Fund's facility in Ft. Collins, Colorado were released to the region in Yellowstone National Park, Idaho, Wyoming and Montana. In 1984, this facility combined forces with its Cornell founders and moved to Boise to become The World Center for Birds of Prey. A milestone was reached in 1999, when the peregrine falcon was formally "delisted" or removed from the list of animals categorized as endangered under the Endangered Species Act. Today, there are pairs of peregrines breeding in almost every state across the country. Their adaptation to urban landscapes - specifically modern cities - has allowed the peregrine to thrive in many places that were not occupied historically. Get Out and See Spring is the best time to view nesting raptors in the Snake River Canyon. For a quick outing, take the short drive south of Kuna to the Bureau of Land Management's Dedication Point on the canyon rim. There, perched above the basalt cliffs, you can view prairie falcons, golden eagles, red-tailed hawks, American kestrels and a wide variety of other birds. Among the local songbirds is the canyon wren, a tiny ventriloquist who delights in throwing his voice against the towering basalt cliffs. This developed overlook includes a broad walking path and informative, interpretive signs. When young falcons and hawks fledge from the canyon walls in early June, they often parade past the overlook on unsteady wings. It's a good time to view them with binoculars and snap photos. For a longer outing, drive to the river bottom at Swan Falls Dam and take the lumpy dirt road downstream. From below the cliffs, one can get a better perspective on the true mastery of flight which birds of prey possess. Often representing the symbols of strength and power, raptors have sparked the imagination of mankind for centuries. For more information about birds, and to view live birds of prey up close, consider attending the Migratory Bird Day celebration at the MK Nature Center on Saturday, May 13th. Located behind Idaho Fish and Game Headquarters at 600 S. Walnut Street in Boise, the Nature Center will host activities for the whole family including films, bird walks, bird banding demonstrations and speakers. To learn more, contact the Nature Center at 334-2225.