Before the end of the 10th Century, in the Trans-Caucasus, when conditions were different, numbers of ungulates like Roe deer and wild boars were large enough to sustain predators like the Asiatic lion and cheetah. Eventually, when the number of humans increased, and environmental conditions changed, the number of ungulates dwindled, thus adversely affecting predators, though the Caspian tiger managed to survive there up to the 20th Century, and the Persian leopard still occurs there. The cheetah may have survived in the Trans-Caucasus up to the 13th Century (Vereshchagin, 1952; Avaliani, 1965).