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White-tailed deer have expanded their range in North America over many decades. Since the early-2000s, these deer have moved north into the boreal forests of western Canada. These forests are full of spruce and pine trees, sandy soil and freezing winters with lots of snow. They’re basically your typical winter wonderland in theory — but actually living there can be harsh.
Ecologists haven’t known whether a warmer climate in these forests is drawing deer north, or whether human land development might play a bigger role.