Climate Change and Mountain Birds
Climate change is reshaping ecosystems across the globe, and mountain environments are among the most sensitive to these changes. Hundreds of scientific studies have documented plants and animals shifting their geographic ranges in response to warming temperatures. On average, montane species worldwide are moving upslope by about 11 meters per decade and poleward by roughly 17 kilometers per decade as they track suitable climate conditions.
In the northeastern United States, warming temperatures are expected to significantly alter the distribution of high-elevation spruce-fir forests over the coming centuries. Ecological models project that much of the region’s current spruce-fir habitat could decline by more than 50% as temperate hardwood forests expand upslope. Because many mountain bird species depend on spruce-fir forests, changes in the extent and structure of this habitat are likely to reshape montane bird communities throughout the Northeast.
Species distribution models also suggest that continued warming may push several familiar boreal bird species northward during this century. Some projections indicate that the Northeast could eventually lose substantial breeding populations of species such as Blackpoll Warbler, Yellow-bellied Flycatcher, White-throated Sparrow, Ruby-crowned Kinglet, Red-breasted Nuthatch, and others that are currently common in our high-elevation forests.
Tracking Change in Mountain Ecosystems
To conserve and effectively manage these species, we must first understand how their populations are changing over time. Unfortunately, most long-term bird monitoring programs rely on roadside surveys, which rarely reach the remote high-elevation forests where many montane birds occur. As a result, population trends for these species have historically been difficult to measure. Mountain Birdwatch was created to fill this gap. By surveying birds at hundreds of high-elevation sampling stations across the Northeast, community scientists are helping us track how the distribution and abundance of mountain birds change through time. These long-term data provide some of the clearest insights into how climate change may be affecting montane ecosystems in our region.
Why Mountain Birds Matter
Mountain birds are both ecological indicators and cultural icons of the Northeast’s high peaks. At sunrise in these forests, the songs of species such as Bicknell’s Thrush, Blackpoll Warbler, and White-throated Sparrow define the character of these wild landscapes. Many of these birds are boreal species that reach the southern limit of their breeding range in the mountains of New England and New York. One species, Bicknell’s Thrush, breeds almost exclusively in high-elevation spruce-fir forests and nowhere else in the United States. These birds occupy isolated “islands” of cold-adapted habitat rising above the surrounding hardwood forests. Because of their strong ties to climate-sensitive habitats, mountain birds can serve as early indicators of environmental change. Tracking their populations helps us understand how climate change is reshaping our region’s forests and provides essential information for conservation planning.
