Sea Lions (Zalophus californianus) are one of the largest animals in the Galapagos, with males weighing up to 550 pounds.  They live in colonies dominated by one bull who guards his turf from other males.  Often a single adult female will watch over the young pups while the other mothers are fishing.  What is the difference between a sea lion and a seal?  Only sea lions have exposed ear flaps and swim using their front flippers (seals use their hind flippers).