October 2015

Field Notes: Baltimore Oriole Feeds Baby Tufted Titmice

Mike O'Connor

September 22, 2015 2 MIN READ Field Notes

Editor’s Note: Mike O’Connor is owner of Bird Watcher’s General Store in Orleans, Massachusetts, and a columnist for The Cape Codder newspaper. This Field Note is adapted from his “Ask the Bird Folks” column of June 19, 2015.

In June 2015, a woman from Chatham, Massachusetts, phoned Bird Watcher’s General Store with an unusual story and question:

A pair of Tufted Titmice has built a nest in our fourteen-year-old birdhouse. We were watching the adult titmice deliver larvae to their babies today, when suddenly another bird joined in. It was a male Baltimore Oriole. The oriole landed on the entrance hole of the birdhouse, stuck its head inside and fed the baby titmice. Is this normal?

When I first received Nora’s call I was skeptical, but decided that her story needed to be documented. I yelled to my son Casey to grab his camera and we headed out to her Chatham home. As soon as we arrived I understood why Nora had so many birds. Her yard was beautiful, with a minimal amount of landscaping and lots of natural habitat. She pointed out the charming 14-year-old moss-covered birdhouse, which looked like something hobbits might live in. Casey and I sat down and waited for this alleged titmouse-feeding oriole to arrive. We didn’t have to wait long.

Thirty seconds into our vigil a streak of orange came screaming across the sky. The male oriole arrived chattering and singing, with his mouth completely stuffed with worms. The oriole then flew straight to the box, stuck his head in the hole, and fed the baby titmice, just like Nora told me he did. I stood there amazed by what I was seeing. My son Casey began to photograph the action.

The show continued when the real parents arrived with food. The oriole wasn’t about to let some other birds get near his babies and quickly dove at the titmouse couple. They were forced to sit back and wait for the oriole to be distracted before they could finally feed their own chicks. Don’t get me wrong; the oriole did not appear to be a hindrance to the nestlings. He seemed to be an excellent stepfather. Casey even took a photo of him carrying away one of the chick’s fecal sacs.

The next thing Nora wanted to know is: why is this oriole feeding some other bird’s babies? I wasn’t sure myself, so I sent the photographic evidence off to some birding experts, and also posted it on the definitive source of all information… Facebook. Amazingly, over 24,000 people saw my post of Nora’s oriole. One reader, Janice, offered a link to a paper written by Marilyn Muszalski Shy (1982) on interspecific feeding. While interspecific feeding is rare, it is not unheard of. In her paper, Shy noted 140 documented cases, which isn’t a lot considering that each year birds produce billions of normal nests. I suspect the oriole has likely lost his own babies to predators and as a result is focusing his attention on the little titmice. Or perhaps while he is waiting for his own eggs to hatch, he prematurely jumped into feeding mode, heard the begging titmice and thought, why not try something new and different? Whatever the reason, it sure made for a serendipitous birding adventure. Plus, it was a good excuse for me to get out of work for a few hours.