Every other Friday on Morning Edition, Outside/In host Sam Evans-Brown tackles a question from a listener.
Susanne from Rumney asks: "I’ve been going for a walk every morning since we’ve been quarantined. So, I’ve noticed lately that I’ve heard a lot of woodpeckers in the morning and I haven’t noticed them before. And I wondered if there are more of them or if this is the time of year that they are seeking wood from the trees?"
There are a lot of reasons that Susanne might be hearing more woodpeckers than ever. And so we’re going to run through all of them in a lightning round. Ready?
It’s spring. “This is when birds start to claim to territories,” says Joan Walsh from Massachusetts Audubon, “and the way that woodpeckers claim territories is by talking a lot!”
Coronavirus induced sampling bias
There’s a chance that because of a change of routine, you’re doing a different kind of walk than you used to, and passing through more woodpeckery places: forests with more dead trees for instance. If you live suburbanly, there is also a bird feeder effect.
“There have been a few studies that have found that their numbers are greater near feeders, and in suburban areas that have a lot of bird feeders than in other areas,” says Amanda Rodewald from the Cornell Lab of Ornithology.
Mast! (It always comes back to mast)
Last year was a pretty good mast year. For those who are not veterans of Ask Sam, many of our trees have evolved a boom-bust cycle of seed and nut production — perhaps as an adaptation to overwhelm squirrels — which leads to many weird cascading ecosystem effects.
One of which is more woodpeckers! “It might have been this last fall and winter it was a really stellar year for acorns or other nuts the woodpeckers like so they’ve been hanging around after the fact,” says Rodewald.
Our first three explanations all drive the short-term changes: year-to-year ups and downs in woodpecker numbers. The last two reasons might not be the reasons our caller has noticed a change this spring, but they’re the real trend.
The first is that the whole region has been reforesting for a couple of generations now, and our existing forests have been getting older. Which means “very large woodpeckers like pileated can now find a suitable nest tree in places that forty years ago, the trees just weren’t big enough,” says Walsh.
There are also simply more trees that get old enough to die, meaning more bugs to eat.
If you look at our big, multi-decade data sets — the USGS breeding bird survey, Audubon’s Christmas bird count — they all show rising populations of all sorts of woodpeckers, because there’s just more wood to peck!
This is one that foresters are worried about. We’ve got more forest pests than ever, including invasive ones. For example, the Emerald Ash Borer has been killing huge quantities of ash trees throughout the midwest and northeast.
“There have been a few studies that have found that in locations that have had high mortality of ash trees due to this emerald ash borer, you do in fact see greater numbers of many woodpeckers,” says Rodewald.
So, invasive bugs — which are generally bad in almost every way — but do provide snacks for some.
Sam Evans-Brown, is host of NHPR’s Outside/In which you can subscribe to where-ever you get your podcasts. If you’d like to submit a question you can record it as a voice memo on your smartphone and send it to firstname.lastname@example.org, OR call the hotline, 1-844-GO-OTTER, OR submit it here.