Mountain Ash Berries: The Songbird Migration’s Drive-Thru

hartleyrobinI came upon the mountain ash tree on an early-morning run today. It’s one of two that grow atop a modest cliff in Duluth’s Hartley Park. Mountain ash trees are the ones that, in fall, hang heavy with clumps of red-orange berries.

The trail I run passes close to these trees, and I’ve been hoping to come around the bend one day and see the tree filled with cedar waxwings or robins. Birds love mountain ash berries. I’ve sat and watched 20 or 30 waxwings feeding in these trees in the fall. Sometimes robins.

A swarm of voracious waxwings can denude a mountain ash tree of its berries in one morning’s feeding. Then they move on to another. Duluth birder Laura Erickson has watched waxwings feeding this way and says it sometimes happens that a bird farthest out on a branch will pluck a berry and pass it along to another waxwing on the branch, and that one will do the same. It’s Erickson’s theory that this multiple handling of a single berry breaks it down, softens it up, so it’s more easily digested by the waxwing that finally ingests it. Maybe so.

Waxwings are handsome birds, cardinal-size but a creamy yellow-buff with a cardinal-like crest on their heads. Put a bunch of them in a mountain ash early on a September morning when the light is just right, and you’ve got one of those moments in the natural world you won’t soon forget.

But this morning, no waxwings or robins adorned the mountain ash that I ran by. And only a few berries remained. Just the day before, it had been laden with them. I knew the birds had found it. Only a couple of clumps of berries remained, and the second mountain ash had also been heavily grazed upon.

I would love to have been there when it happened, but such is not always our luck. It’s good to know, though, that the birds are well-nourished as they continue their migration south.