My selection of a writing topic is not always an easy thing. Sometimes I sit down to the keyboard and find myself completely stuck. I haven’t had an idea all week and at the last minute I still find myself with nothing to focus on. These are the darkest mornings for any writer. You go to the well, but the well is dry.

Other mornings are a little brighter. I might have a couple ideas, but I don’t really love any of them.

This is when I start making little lists and weighing the pros and cons of each idea. Then I do something unrelated to the task of writing. I might open some mail, or tidy up my other desk, in an effort to distract myself and allow a winner to rise to the surface.

And then there are topics like the one I share with you today. I have a clear idea in my head and a clear path forward and it is all due to readers like you. Friendly, observant people who write in with questions about something that they have seen will often choose the topic for me. Specific to today’s column, I received many independent emails from readers who had seen the same mysterious woodpecker.

So, it is with a rare and wonderful clarity of purpose that I present to you the Yellow-bellied Sapsucker (Sphyrapicus varius). This bird has apparently been turning up all across western Massachusetts and it has been giving people fits and starts as they try to figure out just what it is. I’ve read notions that it might be a Ladder-backed Woodpecker, or even a Williamson’s Sapsucker, and these efforts show just how unusual the bird is for some people.

The Yellow-bellied Sapsucker is a medium-sized woodpecker that lives in the forests around us but is (I would hypothesize) rarely seen. I can say with no embarrassment that it was years, perhaps even decades after taking a formal Ornithology course, before I finally laid eyes on one of these birds. The thing is that they don’t often come to feeders, which is where many birds are easiest observed. So, to find one of these birds you have to know what to listen for, when and where to listen for it, and what to look for when you finally hear it.

As its name would suggest, the sapsucker is a bird that relies on tree sap for a good portion of its diet and because the sap doesn’t flow in the winter, the birds are not particularly common during the cold months of the year this far north. The usual northern limit of the sapsuckers winter range is New Jersey, but this has been an El Nino year and temperatures have been much more mild than usual. I would speculate that this might explain the large number of birds that decided to stick around rather than migrating south.

In the springtime, when the sap starts flowing, the birds will fly up from the southeastern U.S. and they will fan out across North America from Pennsylvania northward to mid Quebec and then northwestward from the extreme northeast corner of North Dakota to the eastern border of Alaska.

They look for trees such as Paper Birch and Sugar Maple, which are known to have high levels of sugar in their sap. In the springtime the birds will drill neat rows of little holes that go just deep enough to intercept sap that is rising up from the roots toward the leaves. This, coincidentally, is the same idea used by people who make maple syrup.

In the summertime, the birds drill different holes that target sap flowing down from the leaves back toward the roots. Even richer with sugars, this is the energy-rich food that keeps the sapsuckers going.

It also attracts insects that the woodpeckers will happily eat. But this sap also attracts the attention of Ruby-throated Hummingbirds, which the sapsuckers are not happy to see. As a result, sapsuckers may spend quite a bit of time defending their sugar trees from hungry hummingbirds. However, hummingbirds are diabolically fast, so they do manage to pilfer some of the food for themselves.

I have selected a photo of an adult male Yellow-bellied Sapsucker to share with you today. I took this photo in August last summer and I love it because it has an “Audubon feel” to it. The bird is in an unusual pose, but all of the most important field marks are there for the eye to feast upon. The most important of these is the red on the forehead. If you see a bird with this mark then you are almost surely looking at a sapsucker. Adult males are the only birds with the red chin.

There is also a chance that you might see an immature bird at this time of year. A lack of black feathers and perhaps only a suggestion of the red feathers would indicate this. Instead of being black, the feathers of the immature would be a lighter, nondescript shade of gray-ish tan. Just a few years ago I saw an immature bird at one of my feeders and I’m not sure that I ever really managed to be comfortable with my ability to determine the bird’s sex.

So, it is with much gratitude that I thank the readers who wrote in about a mysterious woodpecker that had been hanging around. I have a healthy population of these beautiful birds in my woods every summer, but seeing them in the winter is a rare and wonderful treat. Thus far I have seen nary a one, so count yourself lucky if a sapsucker is spending the winter with you.

Bill Danielson has been a professional writer and nature photographer for 26 years. He has worked for the National Park Service, the US Forest Service, the Nature Conservancy and the Massachusetts State Parks and he currently teaches high school biology and physics. For more in formation visit his website at www.speakingofnature.com, or go to Speaking of Nature on Facebook.