The Spanish Red deer is one of the largest deer species. In winter its coat is rough and thick of a grey-brown colour and a darker yellowish rump patch.
In summer the coat is reddish-brown. Only stags have a thick neck and carry antlers. They start to grow in spring and are shed at the end of winter. Antlers grow huge with a rough surface and in case of the largest stags, the fourth or fifth tip form at the end a basket. Red deer usually stay in same sex group for the most of the year.
During the rut, mature stags fight for the control of the harems. Rival stags challenge opponents by belling and walking side by side. If neither stag backs down, a crash of antlers can occur, sometimes causing serious injuries.
Only mature stags hold a harem and during that time they rarely feed, loosing up to 20% of the body weight.