Climate change is progressing and adversely affecting our montane plant and animal communities. There are now hundreds of studies (e.g., here) from across the globe documenting plant and animal species responding to changing climatic conditions, and especially warming temperatures. The core ranges of montane species are globally shifting upslope 11 m and polewards 17 km per decade, and these rates are likely to increase as global temperatures rise further.
Here in the northeastern U.S. over the next two centuries, ecologists predict that climate change will greatly diminish existing spruce-fir forest stands by >50% as hardwood forests move up in elevation (see here and here). In conjunction with warming temperatures and diminished spruce-fir forests, species distribution modeling predicts that northward range shifts within this century will result in our northeastern region no longer hosting sizable breeding populations of Blackpoll Warbler, Pine Warbler, Yellow-bellied Flycatcher, Magnolia Warbler, White-throated Sparrow, Ruby-crowned Kinglet, Red-breasted Nuthatch, Evening Grosbeak and perhaps ~30 other familiar species.
To conserve and effectively manage our montane bird species we must, as a very first step, track how the distribution and abundance of these populations change through time. Existing roadside monitoring programs are insufficiently capable of tracking changing in montane bird populations, because the core of these species’ populations predominantly occur in roadless areas.
With this evolving report, we try to answer one seemingly simple question: what is the state of the mountain birds of the northeastern United States? Using long-term data collected by community scientists working on the Vermont Center for Ecostudies’ Mountain Birdwatch project, we have created indicators of population health for each species that we monitor. These indicators reveal which species are thriving and which may be in need of our help. In doing so, we seek to understand where our conservation efforts have succeeded and where they have not.
Why Mountain Birds Matter
They are bellwethers of change and a source of joy. Sitting atop a mountain at sunrise, listening to the dawn chorus of bird song, provides for many people a visceral connection to one of our region’s last truly wild landscapes. These birds are icons of our mountains, and those special places would not be the same without them. The birds of the northeastern U.S. high mountains are mostly boreal species at the southern extent of their breeding range. One species, however, lives only on these mountains, and nowhere else: Bicknell’s Thrush. All of these birds find a home in the islands of spruce and fir that rise from the sea of temperate hardwood forests below. Together, they make up an entirely unique piece of our natural heritage, just like the Grand Canyon or the Everglades. Documenting and understanding how climate change is affecting these forests is important, both as an act of bearing witness and in the hopes that we might learn how to minimize the effects. Tracking populations of mountain birds is an effective and efficient way of doing so: birds are sensitive indicators of environmental change and are relatively easy to study.