The main difference between the sexes in this species is that the males have horns and the females don't. So obviously the horns must be used exclusively for fighting. These two played at fighting a little bit, but it was easy to see that they didn't really mean it. :-)
Their enclosure was fantastic, so much rock and cliff to climb on ... and it was several times bigger than we initially thought it was.
The female was resting in the shade. She was the sensible one, unsurprisingly. ;-) She obviously was still working on shedding her winter coat ... !
(Photo credit: top two, bottom: me; third from top: KAS)