We love to hang bright red feeders to welcome the hummingbirds when they arrive in May. But without flowers in bloom, how would they feed themselves without our help? The yellow-bellied sapsucker keeps them fed.
You may not have seen sapsuckers – you may even have thought the name was just a joke used in Bugs Bunny cartoons – but you’ve probably seen the evidence they leave behind.
Sapsuckers are a specialized type of woodpecker. While their cousins drum on trees to get at the tasty insects hidden within, sapsuckers have a much sweeter tooth. As their name implies, they’re interested in the sap that’s flowing just beneath the surface of the bark.
Since the sap is found everywhere, they don’t need to go all over the tree looking for insects: they just choose a perch, tap a hole and sip, and then move a couple of centimetres to the left or right and do it again. From time to time they will return to the same holes, feeding again once the holes have refilled with sap – a bit like a farmer going along the sap line and emptying buckets of maple sap.
While the birds aren’t always visible, the evidence they leave behind is unmistakable: horizontal lines of holes, each one a few millimeters in diameter, ringing the trees.
What does all this have to do with hummingbirds? The two species of birds have forged an interesting partnership.
When the sapsuckers drill a hole – called a well – they take a sip of the sap, then move on to the next hole. But the sap doesn’t stop running: it continues to dribble into the well.
Since the sugar content of sap is similar to that of nectar, it’s perfect food for the hummingbirds, who come along behind the sapsuckers and take a meal.
Hummingbirds aren’t the only creatures to feed at sapsucker wells. There are dozens of other birds, insects, and even some mammals like bats and porcupines that feed at them as well.
But as anyone who has watched hummingbirds at a feeder knows, hummingbirds hate to share anything. The tiny pugilists will chase anyone and anything away from their food source, whether it’s a red feeder filled with sugar water or a productive sapsucker well.
This is where they repay the sapsuckers. A tiny hummingbird will drink a lot less sap than most of the birds it chases away. Since they don’t harrass sapsuckers, the well-drillers get to enjoy some protection from other, larger bandits who would otherwise drain their holes.
It seems to be a pretty good relationship. In fact, hummingbirds migrate into Ontario about two weeks after the sapsuckers. And when hummingbirds are looking for a spot to nest, they almost always choose a spot near some good sapsucker wells, so they can feed again and again from the same holes.
It takes the trees a couple of weeks to skin over the holes. By then, the first of the spring blooms are producing nectar, and hummingbirds can begin to diversify their diet.