Since 2009 organizations including LTBMU, Tahoe Regional Planning Agency, Nevada Department of Wildlife, California Tahoe Conservancy, Tahoe Institute for Natural Science and Sierra Ecotone Solutions have been monitoring peregrine falcons in the Lake Tahoe Basin. Over the years, falcon populations have increased and expanded to new areas of the basin such as Castle Rock on Tahoe’s East Shore. Located in the southeast region of Lake Tahoe near Kingsbury Grade, the granite outcrop is an ideal nesting spot for the special bird. However, with excellent views of the lake, its popularity among climbers and hikers presented a new challenge for the raptors.
In 2017 after several years of success, researchers reported that the Castle Peak falcons’ young did not fledge the nest. This was the same year construction began at the trailhead to expand the parking lot, attracting more people to hike and climb and come in close contact with the falcons. The exact reason the nest failed however, is unknown due to the myriad obstacles the birds must overcome before leaving the nest.
The following year, the collaboration brought on another partner, the Tahoe Climbing Coalition, who worked with the organizations to inform the climbing community to avoid routes closest to the nesting site. The climbing community obeyed these requests, but for the second year in a row the nest failed.
In 2019, the collaboration conducted an experiment by sending volunteers up the climbing and hiking routes nearest the nests while observing the falcons’ behavior. They discovered that hikers caused more distress than the climbers when they traveled above the birds’ nests.
The groups set out to educate hikers about the impacts their actions have on the young birds with signs along the trails.
The Tahoe Rim Trail Association helped place signs requesting hikers not to summit Castle Rock until the birds have fledged. In addition, the climbing coalition’s influence among that community helped encourage climbers to select other routes during the nesting season for the sake of the birds.
This spring and summer, as COVID-19 shelter-in-place orders drove people to spend more time outdoors, TINS noticed an immediate impact on the falcons when hikers returned to where they were nesting. The group was alerted and the partners sprang into action.
TRPA printed signs and installed them on the trail, and the nonprofit Tahoe Fund jumped in to pay TINS for continued monitoring. With the support of the Tahoe Fund, TINS kept the monitoring schedule on track and removed signs as soon as the young fledged.
“Lifting the closure once it’s no longer needed each year gains the confidence of the hikers and climbers using the area, building trust that these voluntary closures are not arbitrary, which in turn leads to better compliance and better outcomes for the birds,” said Will Richardson, executive director of Tahoe Institute for Natural Science. “This was the first year they raised triplets.”
“The goal of this collaborative is to learn more about how the pair of falcons respond to different types of human presence so we can better tailor our management,” said Stephanie Coppeto, wildlife biologist at the USDA Forest Service Lake Tahoe Basin Management Unit, in a press release. “This approach allows us to take the proper actions to protect the future of these birds while keeping the area open. We want to keep it open but encourage people to be mindful of what they’re doing and to be smart about how they’re recreating in the area. We’re thrilled that our collaboration has been able to increase public awareness and we appreciate the public’s cooperation in adhering to the signs and protecting these birds and their young.”
Powerful and fast-flying, the Peregrine Falcon hunts medium-sized birds, dropping down on them from high above in a spectacular stoop. They were virtually eradicated from eastern North America by pesticide poisoning in the middle 20th century. After significant recovery efforts, Peregrine Falcons have made an incredible rebound and are now regularly seen in many large cities and coastal areas.