Scientific Classification
Total Page:16
File Type:pdf, Size:1020Kb
1/12/2015 seaworld.org/en/animal-info/animal-infobooks/california-sea-lion/scientific-classification/ PARKS KIDS SHOP ANIMALS CARE LANGUAGE Scientific Classification → Scientific California Sea Lion Classification Scientific Classification Habitat & Distribution Physical Characteristics Senses Adaptations Communication & Echolocation Order - Pinnipedia Behavior 1. Pinnipeds are seals, sea lions, and walruses. Some scientists classify pinnipeds as a suborder of the Diet & Eating Habits order Carnivora. Reproduction Family - Otariidae Birth & Care of Young 1. Otariids, also referred to as "eared seals", include all sea lions and fur seals. Otariids are characterized Longevity & Causes of by having external ear pinnae (ear flaps) and long flippers. Death Conservation & Research Books For Young Readers Bibliography Otariids have an external ear structure and are also referred to as "eared seals". Genus, Species - Zalophus Californianus 1. The genus name Zalophus comes from the Greek za, a prefix expressing emphasis, and lophos, meaning "crest." It refers to the large crest on the skull of an adult male. 2. Most scientists recognize three geographically separated subspecies of the California sea lion: Z.c. californianus, Z.c. wollebaeki, and Z.c. japonicus. This information booklet concerns Z.c. californianus unless otherwise noted. Fossil Record 1. The earliest otariids appear in the fossil record about 12 million years ago. The first Zalophus fossils date back to the late Pleistocene, about 120,000 to 220,000 years ago. http://seaworld.org/en/animal-info/animal-infobooks/california-sea-lion/scientific-classification/ 1/1 1/12/2015 seaworld.org/en/animal-info/animal-infobooks/california-sea-lion/habitat-and-distribution/ PARKS KIDS SHOP ANIMALS CARE LANGUAGE Habitat & Distribution Scientific Classification California Sea Lion Habitat & Distribution → Habitat & Distribution Physical Characteristics Senses Adaptations Communication & Echolocation Distribution Behavior 1. Z.c. californianus is found along the coast of the eastern North Pacific, from southern British Columbia Diet & Eating Habits to western Mexico including Baja California. California sea lions breed on islands off the coasts of California and Baja California, including the Channel Islands, Guadalupe, San Benitos, and Cedros. Reproduction They also breed on the coast and islands of the Gulf of California, and the Mexican Pacific coast as far south as Isla Tres Marias. Birth & Care of Young 2. Z.c. wollebaeki is found mainly on the Galápagos Islands. Some are occasionally spotted off the coasts of Ecuador and Columbia Longevity & Causes of Death 3. Z.c. japonicus was once found on a select few Japanese islands. Some researchers believe that there are individuals of this subspecies on Takeshima Islands (now claimed by South Korea). Most researchers Conservation & believe this subspecies is extinct. Research Books For Young Habitat Readers 1. California sea lions inhabit rocky and sandy beaches of coastal islands and mainland shorelines. They Bibliography may frequent sandbars; sheltered coves; tide pools; and structures such as piers, jetties, and buoys. California sea lions inhabit rocky and sandy beaches of coastal islands and mainland shorelines. Migration 1. During the nonbreeding months, most males migrate north from breeding grounds. Southern California males migrate to Puget Sound, Washington and British Columbia; males from Baja California migrate to the Channel Islands. 2. Most females either stay within their breeding grounds or move south during nonbreeding months. Population 1. The Z.c. californianus population is estimated at about 237,000 to 244,000. Studies have suggested that the California sea lion population in the United States has possibly increased at an average annual rate of 10.2% since 1983. The Mexico population has remained http://seaworld.org/en/animal-info/animal-infobooks/california-sea-lion/habitat-and-distribution/ 1/2 1/12/2015 seaworld.org/en/animal-info/animal-infobooks/california-sea-lion/habitat-and-distribution/ stable. One of the largest breeding rookeries is found on the Channel Islands. In 1990 the Channel Island population was estimated to be about 89,000 animals, based on a pup count of 25,000. California sea lions are not endangered or threatened. 2. The Galápagos population is estimated at 20,000 to 50,000. This population is listed by the IUCN as "Vulnerable". 3. The Japanese population was estimated in the 1950s to be 200 to 300, but is currently presumed by most researchers to be extinct. http://seaworld.org/en/animal-info/animal-infobooks/california-sea-lion/habitat-and-distribution/ 2/2 1/12/2015 seaworld.org/en/animal-info/animal-infobooks/california-sea-lion/physical-characteristics/ PARKS KIDS SHOP ANIMALS CARE LANGUAGE Physical Characteristics Scientific Classification California Sea Lion Physical Characteristics Habitat & Distribution → Physical Characteristics Senses Adaptations Communication & Echolocation Size Behavior 1. Male California sea lions reach about 2 to 2.5 m (6.5–8 ft.) and 200 to 400 kg (440–880 lb.). At Diet & Eating Habits maturity male California sea lions are much larger than females. 2. Female California sea lions reach about 1.5 to 2 m (5–6.5 ft.) and 50 to 110 kg (110–240 lb.). Reproduction Birth & Care of Young Mature male California sea lions are much larger than females. Longevity & Causes of Death Body Shape Conservation & Research 1. A California sea lion has a fusiform body shape that is sleek and streamlined. Books For Young Readers Bibliography The bodies of California sea lions are tapered at both ends giving them a sleek, fusiform shape. Coloration 1. California sea lion coat colors vary. Generally, adult males are chocolate brown, females and young males are tan, and pups are dark chocolate brown. As adult males age, the hair around their heads lightens to a light tan. California sea lion pups are noticeably darker in color than the adults. http://seaworld.org/en/animal-info/animal-infobooks/california-sea-lion/physical-characteristics/ 1/6 1/12/2015 seaworld.org/en/animal-info/animal-infobooks/california-sea-lion/physical-characteristics/ 2. Most California sea lions appear dark brown to black when wet. When dry, the light to golden brown of the California sea lion's fur is more apparent. When they are wet, they become dark brown to black. Foreflippers 1. A California sea lion's foreflippers are large and winglike. Sea lions have large, wing-like foreflippers. 2. The foreflippers have all the major skeletal elements of the forelimbs of land mammals, but they are modified for swimming. The "arm" bones are shortened, and the flippers are lengthened by cartilaginous extensions at the tips of the finger bones. This illustration shows the major skeletal elements of the foreflippers and the elongated, larger first digit. 3. The first digit is larger than the others. It's strengthened by fibrous tissue along the leading edge. The first digit on the sea lion's foreflipper is longer than the others and contains fibrous tissue along the leading edge. 4. There are no claws or hair on the foreflippers. http://seaworld.org/en/animal-info/animal-infobooks/california-sea-lion/physical-characteristics/ 2/6 1/12/2015 seaworld.org/en/animal-info/animal-infobooks/california-sea-lion/physical-characteristics/ California sea lions have no hair or claws on their front flippers. 5. California sea lions use their foreflippers in an up-and-down, wing-like motion to propel themselves through the water. Hind Flippers 1. Like land mammals, sea lions have five digits in the hind limbs. They are lengthened by cartilaginous extensions. Sea lions have five digits on their hind flippers that are all roughly the same length. 2. Nails are visible on the middle three digits. The middle three digits on California sea lions' hind flippers have noticeable nails that are used to groom their fur. 3. On land, a sea lion can rotate its hind flippers underneath the pelvic girdle, enabling it to support its weight and walk on all fours. 4. In the water, a sea lion extends its hind flippers and uses them to help steer. http://seaworld.org/en/animal-info/animal-infobooks/california-sea-lion/physical-characteristics/ 3/6 1/12/2015 seaworld.org/en/animal-info/animal-infobooks/california-sea-lion/physical-characteristics/ Sea lions have large, wing-like foreflippers, and smaller hind flippers that can be rotated underneath the body giving sea lions the ability to walk and stand on all fours limbs. Head 1. The California sea lion has visible ear pinnae (ear flaps) on either side of its head. Sea lions have visible external ear flaps on either side of their heads. 2. California sea lions have large eyes. 3. There are about 20 to 30 vibrissae (whiskers) on each side of the muzzle, a total of about 40-60. These tactile organs are well supplied with muscles and nerves. 4. California sea lions have 34 to 38 teeth: four large canine teeth, smaller incisors, and cone-shaped cheek teeth. The teeth are designed for grasping and tearing (not chewing) food. Deciduous teeth (milk teeth) are shed before birth. This adult male California sea lion has the typical large, round eyes, numerous vibrissae and large canine teeth of this species. 5. When relaxed, the nostrils are closed. A sea lion voluntarily opens its nostrils by contracting its mystacial (cheek pad) muscles. http://seaworld.org/en/animal-info/animal-infobooks/california-sea-lion/physical-characteristics/ 4/6 1/12/2015 seaworld.org/en/animal-info/animal-infobooks/california-sea-lion/physical-characteristics/ When relaxed, their nostrils are closed. To open their nostrils, sea lions contract their mystacial musceles. 6. Adult male California sea lions have a raised forehead. This area of the skull is called the cranial, or sagittal crest. At about ten years, the male's sagittal crest reaches full size, up to 4 cm (1.5 in.). Females have a lower, smoother forehead. Male California sea lions have a raised forehead called the cranial or sagittal crest.