The fall Bighorn rut is amazing. To watch and hear the head butting is difficult to describe. These two went at it for about 30 minutes and then parted ways with no clear winner. Camera was a Canon 5D Mk III with the Canon 500mm f4 lens on a tripod. Settings as follows. Aperture was 6.3, speed was 1/1250 sec and ISO was at 1250.