• ProjectsMountainsMountain BirdwatchResults

    Mountain Birdwatch Results and Publications

    Explore Mountain Birdwatch data, or for in depth results and interpretation, please see the individual species accounts at our State of Mountain Birds report website (updated in 2020).

    Soda Range, post Mountain Birdwatch survey. Copyright: Marc Faucher.

    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.

    Winter Wrens have declined by 19% to 29% (mean = 24%) since 2011 in the mountains where Mountain Birdwatch is conducted–that’s -3.41% per year (95% Bayesian credible interval = -4.19% to -2.62%). The mean (thick, dark orange line) annual estimate of the Winter Wren local population size within ~110 meters of ~750 Mountain Birdwatch sampling stations. The vertical orange bars present the 95% Bayesian credible interval (a measure of uncertainty) surrounding those mean annual estimates.

    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 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:

    Winter Wren detection probability during Mountain Birdwatch surveys decreases throughout the early morning hours. Detection probability is the probability that a Mountain Birdwatch observer will detect a bird during a 5-minute point count that is within ~100 meters of the sampling station.