• ProjectsMountainsMountain BirdwatchResults

    Mountain Birdwatch Results and Publications


    Blackpoll Warbler numbers in the Mountain Birdwatch immediate study area (50-m circle around each sampling station) declined each year from 2011-2015, before apparently stabilizing at low numbers in 2016. Faded bars estimate the uncertainty (95% credible intervals) in the estimate of abundance.

    With nearly two decades of robust monitoring data, Mountain Birdwatch is helping biologists, land managers, and policy makers make sound bird conservation decisions. Mountain Birdwatch data have been used to analyze how climate change will impact high-elevation bird populations, establish protective management zones in the Green Mountain and White Mountain National Forests, and appropriately site radio towers, wind turbines, and ski trails so as to minimize disturbance to songbirds. We recently published the first fine-scale population estimate for Bicknell’s Thrush–entirely from Mountain Birdwatch data. The resulting article in Ecosphere can be read online for free, and you can interact with or download our online abundance map.

    Each year we analyze Mountain Birdwatch data using sophisticated statistical models to estimate the annual population trends of the bird species that we monitor. These results are available through our continuously updated State of Mountain Birds report, where we assess the health of all mountain forest songbird populations monitored by Mountain Birdwatch. Although species like Black-capped Chickadee and Swainson’s Thrush have thrived in the mountains during recent decades, some species that depend on the region’s evergreen forests of spruce and fir – notably Blackpoll Warbler – appear to have undergone substantial declines.


    We’re continually analyzing these data to help us in understanding how songbird populations are changing in our mountains. We welcome data requests and requests for collaboration.  The following data are available as open data:

    Bicknell’s Thrush detection probability decreases throughout the early morning hours. Detection probability is the probability that a Mountain Birdwatch observer will detect an adult thrush that is within the area during a point count.