In Africa, there are birds called "ox-pickers" that land on large herbivores - antelopes, Cape buffalo, zebras, etc. - and pick and eat ticks and other small morsels off them, hence the name. But I didn't think any North American birds did that - until today, that is. I was on the phone and saw a moose walk by the back deck. I went to another window and another moose was lying down in the snow. As you can see from the photos, a magpie came and landed on the rear of the second moose, and, like the African ox-pickers, started picking little morsels of food off the moose's back. Here's the proof.