Two new scientific studies recently released by Paul Smith’s College Adirondack Watershed Institute (PSC AWI) and Shingle Shanty Preserve and Research Station (SSPRS) have detected continuing patterns of decline in boreal birds in the Adirondacks.
The authors examined avian community changes in lowland boreal habitats and the impacts that temperature and precipitation have on long-term occupancy patterns of boreal birds. Both peer-reviewed papers were recently published in the scientific journal PLoS One. The studies build on more than a decade of monitoring boreal bird populations in lowland boreal habitat.
Lowland boreal habitats are characterized by conifer swamps, open peatlands, and river corridors. It is a relatively rare habitat type at the southern extent of its range in this part of New York State and is particularly vulnerable to climate change.
In an announcement of the research Michale Glennon, Director of Science for PSC AWI, and the lead author of the research said: “The Adirondack boreal is an important breeding ground for large numbers of birds including boreal specialists such as boreal chickadee and Canada jay. These habitats are what makes the Adirondacks a distinctively northern place.”
Previous work by the authors found that the largest and most intact open peatlands in the Adirondacks are most likely to be occupied by boreal species.
Their first study builds upon this work and examines long-term population trends and the role that temperature and precipitation also play in influencing habitat quality. They found that these factors were highly important, but that the relationships with temperature and precipitation differed from predicted patterns for some of the bird species they studied.
“We were surprised to find that several birds were more likely to occupy sites that were warmer and drier on average during the breeding season,” said Glennon. “Boreal habitats in general are not warm and dry. However, the largest boreal habitat complexes, where birds tend to do well, happen to be located in a corner of the Park with relatively low levels of precipitation and where temperatures are relatively higher than the surrounding forested uplands.”
Steve Langdon, Director of the SSPRS, and one of the authors said: “Is it possible that warmer average site conditions reflect short term benefits for these birds such as increased insect prey abundance or nest survivorship,” “but over the long-term warming temperatures and water deficits could result in tree encroachment into currently open boreal peatland systems, changing the habitat structure that these birds favor. Such changes to boreal habitats have been documented around the world, and we only recently began monitoring this in the Adirondacks.”
The second study focused on all bird species inhabiting low elevation boreal habitats and examined which types of species are declining and which are increasing over time. Researchers found that the group of birds being lost most prominently from these habitats are those specialists uniquely adapted to live in boreal habitat, which include olive-sided flycatcher and rusty blackbird.
Birds on the increase in these same habitats were more general forest birds such as the pileated woodpecker, and those more adapted to human activity like the American redstart. The majority of study sites were located on protected New York State Forest Preserve lands, suggesting that climate may be a more likely cause of these changes than other more immediate impacts such as habitat loss and fragmentation.
The authors discuss recommendations for how best to protect boreal habitats in their paper including creating undisturbed buffers around sensitive areas and restricting timber harvests to winter months.
The Adirondack Watershed Institute is a program of Paul Smith’s College. SSPRS is a 23 square mile tract of land located in Hamilton County, New York.
This research was funded by the United States Geological Survey; long-term monitoring has been supported by the New York State Department of Environmental Conservation, Northern New York Audubon, and by the former Wildlife Conservation Society Adirondack Program.
Photo of Boreal Chickadee courtesy Wikimedia user David Mitchell.