Some of the Catskills’ most distinctive high-elevation birds are disappearing, and researchers say growing use of unofficial hiking trails is adding pressure to species already struggling with climate change and habitat loss.
A new study by researchers at SUNY New Paltz found fewer birds living near both official and unofficial trails than in remote areas of the Catskill High Peaks. The strongest effects were found near informal “herd paths” created by hikers traveling off designated trails.
“We’re not saying people shouldn’t hike,” said Kara Belinsky, an associate professor of biology at SUNY New Paltz, who leads the research team. “I’m a hiker myself. Hiking is wonderful because people get to know nature better. But these birds are already under pressure from many different causes, and hiking is one thing we can manage.”
The study focuses on a group of birds that breed only in the cool, high-elevation spruce and fir forests found on the tallest Catskill peaks. Among them are the Bicknell’s thrush, blackpoll warbler, Magnolia warbler and winter wren.
Many spend winters in Central America, South America, the Caribbean or the southern United States before returning each spring to nest in the Catskills.
Belinsky said the Bicknell’s thrush is especially vulnerable because it occupies such a small geographic range.
“They’re here in the Catskill Mountains, the Adirondacks, on some other mountaintops in the Northeast and a little bit in eastern Maritime Canada — and that’s it,” she said.
A shrinking refuge
The research builds on long-term monitoring conducted through Mountain Birdwatch, a community science program run by the Vermont Center for Ecostudies. That broader monitoring has documented steep declines among many mountain bird species across the Northeast, with some of the sharpest declines occurring in the Catskills.
Belinsky’s team wanted to know whether increasing recreational use of the mountains could be contributing to those losses.
Researchers counted birds along heavily used official trails, informal herd paths and remote locations with little or no human traffic.
The results showed birds were less likely to occupy areas near hiking routes, particularly unofficial trails, than undisturbed forest.
Belinsky emphasized that hiking is not the primary reason these birds are declining.
Climate change is shrinking the cool mountaintop forests the birds depend on. They also face habitat loss on their tropical wintering grounds, threats during migration, window strikes, outdoor cats and artificial lighting.
“Hiking is not the main cause,” she said. “The thing is that hiking is something we can regulate here in New York State, and it’s something we as hikers can do something about.”
Why off-trail hiking matters
Several of the species build nests directly on the ground or low in dense young trees, making them particularly vulnerable to repeated disturbance.
Adult birds must keep eggs warm and deliver insects to growing chicks every few minutes. Frequent human or dog activity near nests can interrupt feeding and reduce nesting success.
“It’s not that you’re necessarily stepping on nests,” Belinsky said. “More likely you’re repeatedly disturbing the adults while they’re trying to raise their young.”
She said the breeding season lasts only about six weeks, mostly during June.
During that period, hikers can reduce their impact by staying on designated trails, keeping dogs leashed and avoiding camping above 3,500 feet, where regulations already prohibit it.
Technology has changed the mountains
Belinsky said smartphone navigation apps have dramatically increased off-trail travel in recent years.
Many hiking apps automatically display informal routes after enough users travel them, leading many visitors to assume they’re official trails.
“The apps actually track where you go,” she said. “If enough people go there, the trail — it’s not a real trail — shows up on the app. People don’t even know it’s not an official trail half the time.”
The New York State Department of Environmental Conservation is now considering changes as part of its visitor use management planning.
One option is converting some heavily used unofficial routes into formal trails that can be designed to avoid sensitive nesting habitat while reducing erosion and concentrating foot traffic into a single corridor.
The goal, Belinsky said, is to reduce the number of hikers spreading across entire mountaintops.
“If we hike everywhere all over the island in all different directions,” she said, “they’re just running out of places to go.”
Balancing recreation and conservation
Belinsky acknowledged that conservation measures may require hikers to accept some limits on recreation in order to preserve wildlife.
“We have amazing public lands in New York,” she said. “But as the numbers of humans and the numbers of humans going off trail increase, we may have to accept some limitations on our recreational behavior if we want to leave some space for wildlife.”
Her research project, funded through a contract with the DEC, has completed four years of fieldwork and has one year remaining before the final analysis.
The project has also introduced SUNY New Paltz students to field biology, often taking students backpacking in the Catskills for the first time.
For hikers, Belinsky hopes the study encourages a deeper appreciation of the wildlife around them.
She recommends using the Cornell Lab of Ornithology’s Merlin Bird ID app to learn bird songs and calls while hiking.
“Getting to know the birds will really enrich your hikes,” she said. “And next May, seriously consider sticking to official trails and leashing your pets to give them some space to raise their babies.”
Image: The decline of the Bicknell’s thrush, a migratory songbird that breeds in the Catskill High Peaks, inspired Belinsky’s research. (Rhododendrites/Wikimedia Commons)