These birds are most often found in coniferous trees where they forage for insects. They will sometimes eat the seeds of the tree and drink the sap. They flit, seemingly constantly hopping from branch to branch. When they spot an insect, they tend to hover much like a hummingbird before making their grab. I included this shot, although not very good, because it shows how the crown turns deep orange during breeding season.
An October Empidonax at Cape Race, Newfoundland
2 weeks ago