Poultry, Fisheries & Wildlife Sciences
Open Access

California Sea Lion

Andrea Ravignani^{* *}Correspondence: Andrea Ravignani, Department of Natural Sciences, Ecology and Environment Research Centre, Manchester Metropolitan University, Manchester, United Kingdom, Email:

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Description

Zalophus californianus, also known as the California sea lion, may be found from California to Mexico, including the Baja and Tres Marias Islands, the Galapagos Islands, and the southern Sea of Japan. Because the populations in each location do not interact with one another, they are classified as subspecies. Seasonally, California sea lions move great distances. Zalophus californianus is commonly found near coasts, although it has also been discovered in rivers throughout the northern Pacific coast. Manmade structures like as jetties, piers, offshore buoys, and oil rigs are popular gathering spots for California sea lions. It prefers to live in areas where humans have intervened.

Puppies are 75 cm long and weigh 5 to 6 kg when they are born. Adult males average 2.2 metres in length and 275 kilogrammes in weight, but may grow to 2.4 metres and 390kg. Females are shorter, averaging 1.8 metres in length and 91 kilogrammes in weight, but can grow to be 2 metres long and 110 kg in weight. Puppies have a blackish brown coat that moults after the first month and is replaced by a white coat. After 4 or 5 months, the light brown coat is lost and replaced with adult pelage. Adult males are mainly dark brown, with lighter coloration on the belly and sides. Adult females are dark brown in colour, but they can sometimes seem tan. Zalophus californianus has obvious sexual dimorphism. Adult males have a larger saggital crest and lighter pelage than females. Males are more robust and larger than females, in addition to having a larger head. All California sea lions have black flippers with short black stubble on them. The most common dental formulas are 3/2, 1/1, and 5/5.

During the mating season, males establish territories. A guy continually occupies a territory until circumstances change and he is displaced. The average occupancy time is two weeks; few Z. californianus males stay at their location for longer. Males remain present when protecting their area and do not depart even while in search of food. Males replace other males in the territory as external conditions alter. Throughout the breeding season, replacement occurs. Males are known to attack if their area is invaded. California sea lions like to nest on isolated islands or beaches. Zalophus californianus has moderate to high polygyny and lives in colonies with a few males and numerous females. Female Z. californianus show mate preference by "respond[ing] differently to the efforts of diverse males."

Early July is the prime breeding season. The entire gestation period lasts around 11 months. The bulk of births occur between mid-May and mid-June, with the majority of pups born in mid-June. The period between birth and estrus is around 28 days. Between the ages of four and five, California sea lions reach sexual maturity. Lactation lasts from six months to a year in Z. californianus. There are several probable explanations for the difference in lactation durations, including food availability, the mother's age and health, the sex of the pup, and the delivery of a new pup.