 The tortoises are ectothermic ( cold @-@ blooded ) , so bask for 1 – 2 hours after dawn to absorb the sun 's heat through their dark shells before actively foraging for 8 – 9 hours a day . They travel mostly in the early morning or late afternoon between resting and grazing areas . They have been observed to walk at a speed of 0 @.@ 3 km / h ( 0 @.@ 2 mph ) . 
