We used radiotelemetry and searched with a trained hound to locate the
dens of 3 recently parturient mountain lions (Felis concolor). These
dens were located in dense riparian vegetation along the same stream i
n the bottom of a steep canyon. We monitored the circadian temperature
s of 2 dens at 1-h intervals and compared them to ambient temperatures
recorded simultaneously. We found mountain lion dens to effectively m
oderate high ambient temperatures, but these dens failed to provide a
thermal advantage at the lowest ambient temperatures recorded in this
investigation. We conclude that mountain lion dens provide effective p
rotection from thermal maxima for young, immobile kittens.