Dave...
well first of all you have to be REALLY nice and walk up behind it ...lift the tail real polite like... and check to make sure there is an Oxpecker.. some times they are a very small,shy .. pecker . so you might have to stick you head between his legs to get a really good look....
The other way to see an Oxpecker.. is to dress like a cow get on all fours... and moooo really sweet like.... more times than not they sneak up behind you so be ready....