New England’s winters have long been a punishing force. Forests fade in and out of deep freezes. Animals pile on fat for warmth in anticipation of the harsh weather to come. Others flee south, seeking warmer refuges. However, over the past 50 years, winters there have become much milder. In the northeastern U.S., winters now average between 4 and 5 degrees Fahrenheit (2.2 and 2.7 degrees Celsius) warmer than in the 1970s. Snowfall can be sparse, and there are usually fewer days of extreme cold. For decades, ecologists have expected that animals living within narrow climate niches would adapt to rising temperatures by moving northwards or upslope to higher elevations. For example, they thought the American red squirrel (Tamiasciurus hudsonicus) in the northeastern U.S. would move up into the mountains in search of cold. But in a study published last year, scientists found that despite warmer winters, the squirrels haven’t sought out higher elevations. Rather, they’ve relocated downslope, seemingly drawn by the return of red spruce forest following a period of dieback. The tiny forest critters, it seems, are prioritizing habitat over temperature. The red squirrel isn’t alone. Thousands of plants and animals that scientists thought would be on the move in response to rising global temperatures don’t yet seem to have hit the road. In a 2023 study in the journal Environmental Evidence, scientists reviewed the observed range movements of more than 12,000 species, both terrestrial and marine, to see whether they aligned with what ecologists had expected would…This article was originally published on Mongabay

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