The Mystery of the Missing Acorns

I was somewhat surprised to read in the Washington Post yesterday that oak trees from northern Virginia to Nova Scotia failed to produce any acorns this year. Last year there were plenty, so what happened? Are the trees sick? Could it have anything to do with climate change? (Warmer weather out west seems to be allowing parasites to thrive that cause sudden aspen decline and other tree diseases.) Or is it just part of the natural cycle for these trees?

Oak trees, at least in the D.C. area, pollinate in one or two weeks usually in May. Mess with the pollination period and there will be no acorns in the fall. Insects, such as gypsy moths, can damage trees but don't really affect the pollen. A late frost can kill the trees' flowers and cut off pollination, but we didn't have a late frost. What we did have, though, was rain. Days and days of rain, adding up to more than 10 inches at National Airport on the Potomac River, according to the National Weather Service.

Was there enough rain to wash away all the pollen and prevent the trees from creating acorns? Maybe. No need to worry just yet; the acorns will probably be back next year. And the oak trees, which can live up to 300 years, will survive. The squirrels, though, could have a hard winter ahead.

Have you seen any acorns this year? Or do you have any other theories on what might be happening?

Editor's Note: We are aware that the above photo is of a European species of squirrel and would be unaffected by the acorn problems facing his North American brethren. But that photo is just too darn cute and funny, so we're sticking with it.

Sarah Zielinski | | READ MORE

Sarah Zielinski is an award-winning science writer and editor. She is a contributing writer in science for Smithsonian.com and blogs at Wild Things, which appears on Science News.