Same for the bike trails around my town.  There are parts where it's wide enough to accommodate 8 humans to walk side by side yet the fat fucks still manage to block it off completely with as few as 2 (it's all in the arms sticking out, swinging about as they waddle). "On your left" is the polite, quick way to let people know you're about to pass them, humans typically have a quick "Shit, which side's left again?" moment, laugh, then greet you as you pass by.  Cows?  They'll just completely ignore you. It's gotten to the point where I'll have to ride a couple of feet directly behind them yelling "ON YOUR LEFT" louder and louder until they snap out of their food fantasies, then call me an asshole as they give me the minimum amount of space to squeeze by.