Several duck species have been heading north in recent decades, according to an ambitious new study that both confirms and complicates some popular impressions.
Prompted by public concern about climate-driven changes in the duck world, a team of scientists examined 60 years’ worth of data to determine that mallard and northern pintail winter range distributions have shifted eastward and northward by as much as 180 miles.
Over the same period, blue teal winter range distributions shifted westward and southward. The researchers caution, though, against making premature assumptions about cause and effect.
“It’s a lot more complicated than just broadly saying the duck distributions are shifting,” study co-author Lisa Webb said in an interview. “There’s a lot of variation in the shifts among species and even … within subspecies. And then, depending on the month that you’re looking at, it can vary as well.”
