Presentation on theme: "The Elephant Seal Mirounga anustirostris. Pinniped pinna = feather or wing pedis = foot Fin footed marine mammal Four limbs modified as flippers Streamlined."— Presentation transcript:
Pinniped pinna = feather or wing pedis = foot Fin footed marine mammal Four limbs modified as flippers Streamlined body
California Pinnipeds Eared Seals –External ear flaps –Fur seals and sea lions –Hind flipper turns forward Move about on land quickly Sea lions = circus seals True Seals –Harbor seals & elephant seals –Lack external ears –Clumsy on land
Elephant Seal Largest pinniped –Males 14-16 ft long, 3,000-5,000 lbs –Females 9-12 ft & 900-1000 lbs Northern elephant seal ranges from Baja, CA to Vancouver Island Diet of squid, small shark & fish Sexual dimorphism
Annual Cycle Bulls arrive in Dec – stake out territory Only 6% of males will get lucky ( a harem) Pregnant females begin to arrive in late Dec & Jan Females will give birth to pup within 3 days after arriving on beach Pups nurse for about a month –Will quadruple weight –Moms milk is 55% fat
Northern Elephant Seal Life Cycle Females nurse young for about a month Babies wean – “weaners” Moms come into estrus Mate before leaving Females fast while on beach
Weaners live together for about 2 months Learn to swim and leave the beach Mar-May spring molt Jun – Aug Summer molt
Piedras Blancas Rookery Less than 25 seals on beach in 1990 First birth in 1992 50 pups born in 1993 By 1996 >1000 pups born –Population explosion!