A very curious Red-breasted Nuthatch was interested in the what we were doing in Fish Creek Park just on the southern end of Calgary. There is a saying that gives a bit of a hint as to what you might be looking at moving up or down the trunk of a tree. Nuthatches down, and Creepers up. It doesn't work 100% of the time but I would say at least 85%. In this case horizontal works just fine.