san francisco zoo 9/28/15 california sea lion (zalophus californianus) talking points...

San Francisco Zoo 9/28/15


CALIFORNIA SEA LION (Zalophus californianus) TALKING POINTS SEA LION BAG INVENTORY

• Sea Lion Skull • Sea Lion Pelt • Sea Lion Resource Notebook

CA SEA LION RANGE: Along the West Coast from Vancouver Island to Baja, CA (see map) HABITAT: Coastal waters to depth of 1000 feet as well as harbors, rivers and beaches. CA SEA LION PHYSICAL ADAPTATIONS:

1. General Physical Characteristics • Streamlined bodies and long snouts for passing through water efficiently, highly

flexible spine, short hairs, smooth skin when wet. • Fastest swimmer among the seal and sea lions, up to 25 MPH for short bursts. • Older males identified by bump on the top of the head.

2. Size/Weight/Lifespan • Sexually dimorphic: Males up to 1000 pounds, 10 feet long, Females smaller than

males, about 600 pounds and average 7 feet • Thick layer of fat (blubber) acts as insulation • Longevity: In wild about 20 years, in captivity, 30 years

3. Nose: • Nostrils close instinctively when entering the water. Will remain closed until they

need to surface. • Smooth whiskers assist in finding food. (seals have beaded whiskers)

4. Teeth: 42 sharp pointed teeth to grab and hold prey as appropriate for a marine carnivore.

5. Flippers: Uses fore-flippers to propel itself when swimming and able to rotate rear flippers forward and walk on all fours when maneuvering on land

6. Eyes: • Large with retina adapted for low light conditions, such as found under water. • Probably near sighted. • Can see in color, though limited to the blue and green spectrum, which is appropriate

for the marine environment 7. Hearing /ears:

• Small external ear flap • Good hearing both under water and on land

CA SEA LION BEHAVIORAL ADAPTATIONS:

1. Lifestyle • Outside of their breeding season, sea lions spend much of their time at sea • Come ashore to reproduce and to molt. • Often seen on sandy or rocky beaches, but they also frequent manmade

environments such as wharves and marinas. Pelt helps protect skin from abrasions on shore.

• Marine carnivores 2. Diet: Fish, squid, sometimes clams



3. Breeding/Reproduction/Growth/Parental Care: • Large males tend to establish breeding territories in rookeries located generally in the

Channel Islands of California. • Male breeds with multiple females who often arrive already pregnant. • During breeding, they will fast, relying on a thick layer of blubber for energy. • Births take place in June and July. • Nine-month gestation period. • Implantation of fertilized egg takes place after a three-month delay to continue the 12-

month reproductive cycle the females experience • Pups are abruptly weaned and abandoned at 6 months. These young pups are often

swept into the water during storms and latter rescued by places such as the Marine Mammal Center in Sausalito, California.

4. Communication: • Sea lions are gregarious with numerous vocalizations, including loud barks and

mother-pup contact calls. • Sea lions rely on their whiskers or vibrissae for touch and detection of vibrations

underwater. SEA LION PREDATORS: Sharks, Killer Whales (Orcas) and man. SEA LION ILLNESSES: susceptible to certain human illnesses such as pneumonia, epilepsy and various types of cancer CA SEA LION INTERESTING/FUN FACTS:

• These are marine mammals, known as pinnipeds, which means they have "winged feet", referring to their flippers. The seal on RCA records balancing a ball is not a seal but a sea lion since true seals can't elevate their heads and shoulders that high. (see photo sea lion versus seal)

• A group of sea lions is called a colony or pod. • Can stay submerged for up to 12 minutes, dive as deep as 1760 feet, slowing heart beat

allows them to achieve these results. • Adult males are called bulls, females are cows and the young, pups. • San Francisco Pier 39 Sea Lions: Started appearing in late 1989 after the earthquake

and originally hauled out on the docks used by boaters. Because they are protected marine mammals the boats were relocated and special docks built to accommodate the sea lions. These are cleaned off once a week by high-pressure hose to prevent the area from becoming too odiferous. Most of the sea lions there are male. Sometimes the entire group disappears in search of new food supplies. (see photo)

• The CA Sea Lion is the noise of the velociraptor in “Jurassic Park” and also the Orcs in the movie “Lord of the Rings”.

CA SEA LION CONSERVATION ISSUES:

• Plastic debris in the oceans, algal blooms (produces neurotoxins that are harmful to sea lions and can cause seizures), polluted water

• Climate changes, warming of oceans have led to reduced food supply and longer foraging trips for adult females leading to increased mortality for the nursing pups left on shore.

• Protected under Marine Mammal Protection Act of 1972 with a classification of Least Concern. Their population is growing steadily, and California sea lions can be seen in



many coastal spots such as the Monterey Coast Guard jetty and PIER 39 in San Francisco. The current population is approximately 238,000.

• Sea lions are killed illegally, because it is believed they pose a huge threat to commercial fishermen. They consume large amounts of food from the waters, which means there is less of it for these fishermen to capture and make a profit from. (example: the shooting of Silent Knight, the zoo’s sea lion)

California Sea Lion breeding range in dark blue, total range in light blue

Sexual Dimorphism female Sea lion (left) verses male Sea lion (right)



Sea lion (left) versus seal (right): the ears and flippers distinguish the two pinnepeds

Sea lions at Pier 39 in San Francisco, California



Silent Knight Silent Knight, an adult male California sea lion, was found in Dec, 2010, washed up on a beach in Sausalito. Shot in the face and left for dead, he had at least 5 buckshot fragments in his head and damage to his mouth and jaw. The Marine Mammal Center provided the critical care he needed to recover from his life-threatening injuries, but his devastating wounds left him blind, making him unfit for release back to the wild. Once healthy, he was brought to the San Francisco Zoo where he acts as an educational ambassador, carrying the message to treat all creatures kindly. We hope that Silent Knight's story will

highlight the occurrence of these horrific crimes and ultimately inspire people like you to care more about these animals, and inspire greater stewardship of them and their ocean home.

Henry Henry was found malnourished and blind stranded on a beach in Humboldt County in May, 2010. Veterinarians discovered he was blind, though it is unclear what caused his blindness and they don’t believe he was born this way. Henry’s inability to see may have challenged his fishing skills, which ultimately left him weak and unable to swim or fend for himself. The Marine Mammal Center provided the care he needed to recover but his blindness made him unfit for release back to the wild. In May, 2011, he was sent to the San Francisco Zoo. In 2017, Henry had an operation by a veterinary ophthalmologist specializing in marine mammals. The right eye was removed due to increasing pain and discomfort. A cataract was removed from the left

eye; Henry can now differentiate between light and dark in his left eye.

san francisco zoo 9/28/15 california sea lion (zalophus californianus) talking points...

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