Way up in a tree on the Bates campus, a bird hammered away at the wood on a recent afternoon.

Mindful of Bates’ birding history, I was curious: What species was this rat-a-tapping bird? The possible pecking order, I figured, included two familiar Maine species: the downy woodpecker and hairy woodpecker.

Professor of Biology Don Dearborn, an expert in avian biology, cheerfully ID’d the bird after I showed him a video clip and still image.

It’s neither of those woodpeckers, he said. “It’s a yellow-bellied sapsucker,” he explained, pointing to the black and white mottling on its back “rather than a block of solid white, as with the downy or hairy.”

And, he added, its red throat makes it a male. “Male and female sapsuckers both have a red forehead — though not visible in your photo — but only the males have a red throat.”

You can tell the species and gender of this bird by the red patch on its throat.

The species’ eponymous yellow belly can be “quite variable,” he said. “This one appears to have at least a tiny bit, low on its flanks.”

The sapsucker’s chosen tree, located in a small stand of mixed conifers at the corner of Nichols Street and Campus Avenue across from the Historic Quad, is clearly a spruce.

I asked Brett Huggett, assistant professor of biology and architect of the Bates Canopy website, which species. “Are its branches hanging down?” he asked me. (Yup.) “Then it’s a Norway spruce.”

The sapsucker is a migratory bird, so it can seem a bit more rare in Maine than the year-round downy or hairy woodpeckers. As its name suggests, the sapsucker drills holes in a tree and feeds on the sap that oozes out.

The yellow-bellied sapsucker was doing his thing in a Norway spruce (center), a species characterized by drooping branches. On left and right are red pines. This stand of conifers is at the corner of Nichols Street and Campus Avenue.