This bee mimic was foraging on tiny thistles in the Reifel Island bird sanctuary.
A syrphid fly, probably*.
It's cheating: to simulate bees' antennae, it holds two legs out in front of its head. And it's about the size of a bee, and furry; any bird that skips bees will pass this one by, too.
A bee has four wings. A fly, like this one, has two. Birds aren't supposed to notice this.
Bees have nicely rounded abdomens; syrphid flies' bellies are so thin they look squashed. This one curves downward at the back, so it looks fat from a bird's eye view. From the side, however, the fakery is exposed; that belly is flat!
Notice the unusual shape of the wings; scalloped at the rear end.
I was fooled, too, at least until I got home and looked at the photos. I have advantages a bird doesn't, even with their superior eyes.
* A similar one, from Ontario is here, on BugGuide. Ours is probably in the same Subfamily, Eristalinae. Tweet