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Калифорнийски морски лъв Калифорнийският морски лъв (Zalophus californianus) е ушат тюлен, разпространен по Северноамериканското крайбрежие на Тихия океан. С високия си интелект, адаптивност към успешно съжителство с човекa и лесно поддаване на дресировка, именно този морски лъв е тюленът, който сме свикнали да виждаме в зоопаркове, циркове и аквариуми. Добре обучени калифорнийски морски лъвове се използват дори в морски операции на Американската армия. Съдържание Физическа характеристика[редактиране | редактиране на кода] Мъжките достигат до 2,4 метра дължина на тялото и тежат до 300 kg, а женските са значително по-дребни и рядко надхвърлят 90 kg. Когато достигнат полова зрялост мъжките се сдобиват с костен гребен отгоре на черепа, откъдето идва научното наименование на вида, от латински: loph — чело, а представката za- служи за емфаза, т.е. Zalophus californianus означава Калифорнийско високочело. Полово активните мъжки, или т.нар. секачи имат също така дебел врат и своеобразна къса грива. Малките се раждат тъмнокафяви и тежат около 7 kg. Когато станат на 4-5 месеца, те сменят козината си с по-светлокафява до сребриста. Женските и младите мъжки са по-светли от възрастните мъжкари. Когато козината им е суха, окраската им е шоколадово кафява до червеникава. Разпространение[редактиране | редактиране на кода] Както говори наименованието му, Калифорнийският морски лъв се среща главно по бреговете на Калифорния (САЩ) и Калифорнийския залив (Мексико), като обикновено не навлиза на повече от 20 km навътре в океана. Предпочитани места за размножаване са пясъчните плажове на островите Сан Мигел и Сан Николас. След размножителния сезон мъжките мигрират на север до Британска Колумбия. Тогава могат да се видят струпани по вълноломи, кейове и светещ буй навигационни буйове. Тези конструкции и човешкото присъствие въобще им осигуряват защита от естествените им врагове: косатки и бели акули. Сродни видове[редактиране | редактиране на кода] Доскоро Галапагоските морски лъвове (Zalophus wollebaeki) и изчезналите през 50-те години на 20 век Японски морски лъвове (Zalophus japonicus) бяха считани за изолирани популации Калифорнийски морски лъвове и някои учени продължават да твърдят, че става въпрос за един и същ вид с 3 локални подвида.[2] Начин на живот и хранене[редактиране | редактиране на кода] Калифорнийските морски лъвове се хранят с най-разнообразна морска храна, основно с главоноги (сепии, октоподи) и риба (сьомга, хек, херинга, аншоа и др.). Ловуват самостоятелно или на малки групи, но при наличие на големи рибни пасажи се събират на големи стада и ловуват съвместно с други морски животни, като делфини, морски свине, морски птици и др. През зимната миграция на север мъжките се събират в устията на реки очаквайки миграцията на сьомга и есетрови риби. Най-добре се гмуркат възрастните женски. Навлизайки от 10 до 100 km навътре в океана, те се гмуркат на средна дълбочина от 30 до 100 m, а максималната регистрирана дълбочина на гмуркане е 274 m. Морските лъвове са изразено социални и общителни животни. Най-често издават звуци подобни на кучешки лай. Женските могат да открият своето малко сред хиляди изглеждащи по един и същи начин, разпознавайки го по гласа, звуците които издава и уникалната му миризма. Нормалната телесна температура на калифорнийския морски лъв е 37,5°C и след като няма нито потни жлези, нито се задъхва като кучетата, за да не прегрее в горещи дни се налага често да влиза във водата. Размножаване[редактиране | редактиране на кода] Размножителният период на калифорнийските морски лъвове продължава от май до юни. Те са изразено полигамни животни — мъжките образуват хареми, като излизайки на брега най-силните заемат най-добрите места, запазвайки си правото над женските на своя територия. За да отстояват територията си обаче, необходимо е те да останат колкото се може по-дълго на брега, разчитайки изцяло на натрупаните си хранителните запаси под формата на подкожни мазнини. Така мъжките могат да издържат до 27 дни на глад и горещини, но след като излязат на брега, женските раждат малките си и се разгонват не по-рано от 21-ия ден след раждането. Затова мъжките се активизират и стават много агресивни малко след раждането на малките. Тогава битките за територия и женските в нея стават много ожесточени, като съперниците не само си причиняват сериозни наранявания, но и безогледно мачкат всичко по пътя си представлявайки сериозна заплаха за малките. С напредването на лятото страстите се утоляват и мъжките престават да се бият, заплашвайки се само с лай, поклащане на глава, погледи и посягания. След 12-месечна бременност женските раждат по едно малко. Женската кърми малкото си 1-2 дни, след което го оставя само на брега за 2-3 дни, за да се нахрани в морето. Това продължава около два месеца, след което малкото влиза във водата и остава с майка си близо година. Малките се раждат с отворени очи и бозаят до шест месечна възраст нараствайки неимоверно благодарение на високата масленост на майчиното мляко. Калифорнийският морски лъв е единствения бозайник, чието мляко не съдържа лактоза. Полова зрялост достигат на 4-5 годишна възраст. Природозащитен статус[редактиране | редактиране на кода] Безмилостно избивани в миналото заради кожата, за храна на животни или просто защото се смята, че сериозно вредят на рибните запаси, калифорнийските морски лъвове са били застрашени от изчезване. Благодарение на взетите защитни мерки обаче, днес популацията на вида надхвърля 200 000 екземпляра и той фигурира в Червения списък на световнозастрашените видове на IUCN като незастрашен[3]. Допълнителни сведения[редактиране | редактиране на кода] През 1970 г. сред калифорнийските морски лъвове се разпространява заразната болест лептоспироза, засягаща черния дроб и бъбреците. Болестта е първият известен случай на широкоразпространена зараза сред морски животни. Вероятно болестта е тръгнала от Мексико поради по-топлата вода, която предразполага към развитие и разпространение на бактерии. Продължителност на живота[редактиране | редактиране на кода] В природата калифорнийските морски лъвове рядко доживяват 17 години, но най-възрастният индивид в плен доживял 31-годишна възраст. Стопанско значение[редактиране | редактиране на кода] В миналото калифорнийските морски лъвове са били избивани заради своята кожа и за храна на животни, в резултат на което броят им драстично е намалял. Днес обаче са защитени и нямат стопанско значение. Външни препратки[редактиране | редактиране на кода] Бележки[редактиране | редактиране на кода] - ↑ ((en)) Aurioles, D. & Trillmich, F.. Zalophus californianus. // IUCN Red List of Threatened Species. Version. International Union for Conservation of Nature, 2008. Посетен на 30 January 2009. - ↑ Don E. Wilson & DeeAnn M. Reeder (editors). 2005. Mammal Species of the World. A Taxonomic and Geographic Reference (3rd ed), Johns Hopkins University Press, 2,142 pp. Online - ↑ Zalophus californianus (IUCN Red List of Threatened Species, 2007)
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California sea lion The California sea lion (Zalophus californianus) is a coastal eared seal native to western North America. It is one of five species of sea lion. Its natural habitat ranges from southeast Alaska to central Mexico, including the Gulf of California. Sea lions are sexually dimorphic, males are larger than females, and have a thicker neck and protruding crest. They mainly haul-out on sandy or rocky beaches, but they also frequent manmade environments such as marinas and wharves. Sea lions feed on a number of species of fish and squid, and are preyed on by killer whales and white sharks. California sea lions have a polygynous breeding pattern. From May to August, males establish territories and try to attract females to mate with. Females are free to move in between territories, and are not coerced by males. Mothers nurse their pups in between foraging trips. Sea lions communicate with numerous vocalizations, notably with barks and mother-pup contact calls. Outside of their breeding season, sea lions spend much of their time at sea, but they come to shore to molt. Sea lions are particularly intelligent and can be trained to perform various tasks. Because of this, California sea lions are commonly found in public displays in zoos, circuses and oceanariums, where they are known as the classic "seals," and are trained by the US Navy for certain military operations. The International Union for Conservation of Nature (IUCN) lists the species as Least Concern due to its abundance. Predation by California sea lions on threatened or endangered salmon species at Bonneville Dam has resulted in more than 50 of them being killed by state officials.[2] Contents Taxonomy[edit] The California sea lion was described by René Primevère Lesson, a French naturalist, in 1828. It is grouped with other sea lions and fur seals in the family Otariidae. Otariids, also known as eared seals, differ from true seals in having external ear flaps, and proportionately larger foreflippers and pectoral muscles. Along with the Galapagos sea lion and the extinct Japanese sea lion, the California sea lion belongs to the genus Zalophus, which derives from the Greek words za, meaning "intensive," and lophus, meaning "crest."[3] This refers to the protruding sagittal crest of the males, which distinguishes members of the genus.[4] Traditionally, the Galapagos sea lion and Japanese sea lion were classified as subspecies of the California sea lion. However, a genetic study in 2007 found that all three are in fact separate species.[5] The lineages of the California and Japanese sea lion appear to have split off 2.2 million years ago during the Pliocene.[6] The California sea lion differs from the Galapagos sea lion in its greater sexual dimorphism.[4] The Steller sea lion is the closest extant relative of the Zalophus sea lions, being a sister taxon.[7] Appearance, physiology, and movement[edit] Being sexually dimorphic, California sea lions differ in size, shape, and coloration between the sexes. Males are typically around 2.4 m (7.9 ft) long and weigh up to 350 kg (770 lb), while females are typically around 1.8 m (5.9 ft) and weigh up to 100 kg (220 lb).[4] Females and juveniles have a tawny brown pelage,[4] although they may be temporarily light gray or silver after molting.[8] The pelage of adult males can be anywhere from light brown to black, but is typically dark brown.[4] The face of adult males may also be light tan in some areas. Pups have a black or dark brown pelage at birth.[8] Although the species has a slender build, adult males have robust necks, chests, and shoulders.[8] Adult males also have a protruding crest which gives them a "high, domed forehead";[9] it is tufted with white hairs.[4] They also have manes, which are less developed than those of adult male South American and Steller sea lions.[9] Both sexes have long, narrow muzzles.[8] As an otariid, the California sea lion relies on its foreflippers to propel itself when swimming. This form of aquatic locomotion, along with its streamlined body, effectively reduces drag underwater. Its foreflipper movement is not continuous; the animal glides in between each stroke.[10] The flexibility of its spine allows the sea lion to bend its neck backwards far enough to reach its hindflippers. This allows the animal to make dorsal turns and maintain a streamlined posture.[11] When moving on land, the sea lion is able to turn its hindflippers forward and walk on all fours. It moves the foreflippers in a transverse, rather than a sagittal, fashion. In addition, it relies on movements of its head and neck more than its hindflippers for terrestrial locomotion.[12] Sea lions may travel at speeds of around 10.8 km/h (6.7 mph),[13] and can dive at depths of 274 m (899 ft) and for up to 9.9 minutes, though most dives are typically 80 m (260 ft) and last less than 3 minutes.[14] Sea lions have color vision, though it is limited to the blue-green area of the color spectrum. This is likely an adaptation for living in marine coastal habitats.[15] Sea lions have fairly acute underwater hearing, with a hearing range of 0.4–32 kHz.[16] Sea lions rely on their whiskers or vibrissae for touch and detection of vibrations underwater. Compared to the harbor seal, the California sea lion's vibrissae are smoother and less specialized and thus perform less when following hydrodynamic trails, although they still perform well.[17] Ecology[edit] Range and habitat[edit] The California sea lion ranges along the western coast and islands of North America, from southeast Alaska to central Mexico. Mitochondrial DNA sequences in 2009 have identified five distinct California sea lion populations: the U.S. or Pacific Temperate stock, the Western Baja California or Pacific Tropical stock, and the Southern, Central, and Northern Gulf of California stocks.[7] The U.S. stock breeds mainly in the Channel Islands, although some breeding sites may be established in northern California, and females are now commonly found there.[1] The Western Baja California stock mainly breeds near Punta Eugenia and at Isla Santa Margarita. The above-mentioned stocks are separated by the Ensenada Front. The stocks of the Gulf of California live in the shallow waters of the north (Northern stock), the tidal islands near the center (Central stock), and the mouth of the bay (Southern stock). The stock status of the sea lions at the deep waters of the central bay has not been analyzed.[7] During the breeding season, sea lions gather on both sandy and rocky shores. On warm days, they lie closer to the water. At night or in cool weather, they travel farther inland or to higher elevations.[8] Non-breeding individuals may gather at marinas, wharves, or even navigational buoys. California sea lions can also live in fresh water for periods of time, such as near the Bonneville Dam in the Columbia River.[18] In 2004 a healthy sea lion was found sitting on a road in Merced County, California, almost a hundred miles upstream from the San Francisco Bay and half a mile from the San Joaquin River.[19] Diet and predation[edit] California sea lions feed on a wide variety of seafood, mainly squid and fish, and sometimes clams. Commonly eaten fish and squid species include salmon, hake, Pacific whiting, anchovy, herring, rockfish, lamprey, dogfish, and market squid.[20] They mostly forage near mainland coastlines, the continental shelf, and seamounts. They may also search along the ocean bottom.[8] California sea lions may eat alone or in small to large groups, depending on the amount of food available. They sometimes cooperate with other predators, such as dolphins, porpoises, and seabirds, when hunting large schools of fish.[21] Sea lions sometimes follow dolphins and exploit their hunting efforts.[4] Adult females feed between 10–100 km (6.2–62.1 mi) from shore.[13] Males may forage as far as 450 km (280 mi) from shore when water temperatures rise.[22] They also have learned to feed on steelhead and salmon below fish ladders at Bonneville Dam and at other locations where fish must queue in order to pass through dams and locks that block their passage. Sea lions are preyed on by killer whales and large sharks. At Monterey Bay, California sea lions appear to be the more common food items for transient mammal-eating killer whale pods.[23] The sea lions may respond to the dorsal fin of a killer whale and remain vigilant, even when encountering resident fish-eating pods.[24] Sea lions are also common prey for white sharks. They have been found with scars made by attacks from both white sharks and shortfin mako sharks. Sharks attack sea lions by ambushing them while they are resting at the surface.[25] Sea lions that are attacked in the hindquarters are more likely to survive and make it to the shore.[26] Life history[edit] Reproductive behavior and parenting[edit] California sea lions breed gregariously between May and August, when they arrive at their breeding rookeries. When establishing a territory, the males will try to increase their chances of reproducing by staying on the rookery for as long as possible. During this time, they will fast, relying on a thick layer of fat called blubber for energy. Size and patience allow a male to defend his territory more effectively; the bigger the male, the more blubber he can store and the longer he can wait. A male sea lion usually keeps his territory for around 27 days. Females have long parturition intervals, and thus the males do not establish their territories until after the females give birth. Most fights occur during this time. After this, the males rely on ritualized displays (vocalizations, head-shaking, stares, bluff lunges, and so on) to maintain their territorial boundaries. Since temperatures can reach over 30 °C (86 °F) during this time, males must include water within their territories. Some territories are mostly underwater, particularly those near steep cliffs.[27] Sea lions that fail to establish a territory are driven out to sea or gather at a nearby beach.[4] Before mating begins, females gather into "milling" groups of 2–20 individuals. The females in these groups will mount each other as well as the males. These groups begin to disintegrate as the females begin to mate.[4] The territorial and mating system of the California sea lion has been described as similar to a lek system, as females appear to choose their mates while moving though different territories.[28] They avoid males that are too aggressive or energetic. Males are usually unable to prevent females from leaving their territories,[4] particularly in water.[29] Mating may occur outside the rookeries, between non-territorial males and females, as the latter move to and from the mating site. In some rookeries, copulation may be monopolized by a few males, while at others, a single male may sire no more than four pups.[29] Female California sea lions have a 12-month reproductive cycle, consisting of a 9-month actual gestation and a 3-month delayed implantation of the fertilized egg before giving birth in June or July. Interbirth intervals are particularly long for this species, being 21 days for sea lions off California and more than 30 days for sea lions in the Gulf of California.[29] Females remain with their pups on shore for 10 days and nurse them. After this, females will go on foraging trips lasting as long as three days, returning to nurse their pups for up to a day. Pups left on shore tend to gather in nurseries to socialize and play.[8] When returning from a trip, females call their pups with distinctive calls to which the pups will reply in kind. A mother and pup can distinguish each other's calls from those of other mothers and pups. At first, reunions largely depend on the efforts of the mothers. However, as pups get older, they get more involved in reunions.[30] Older pups may sometimes join their mothers during their foraging trips.[8] Adult male California sea lions play no role in raising pups, but they do take more interest in them than adult males of other otariid species; they have even been observed to help shield swimming pups from predators.[31] Pups are weaned by a year but can continue to suckle for another year.[4] Communication[edit] California sea lions communicate with a range of vocalizations. The most commonly used one is their characteristic bark. Territorial males are the loudest and most continuous callers, and barks are produced constantly during the peak of the breeding season. Sea lions bark especially rapidly when excited. The barks of territorial and non-territorial males sound similar, although those of the former are deeper. Males may bark when threatening other males or during courtship. The only other vocalization made by territorial males is a "prolonged hoarse grunt sound" made when an individual is startled by a human. This vocalization is also made by groups of non-reproductive males.[32] Female sea lions are less vocal. Their barks, high-pitched and shorter than those made by males, are used in aggressive situations. Other aggressive vocalizations given by females include the "squeal", the "belch", and the "growl". The sound a female sea lion gives when calling her pups is called a "pup-attraction call", described as "loud" and "brawling". Pups respond with a "mother-response call", which is similar in structure. Pups will also bleat or bark when playing or in distress.[32] California sea lions can produce vocalizations underwater. These include "whinny" sounds, barks, buzzings, and clicks.[33] Nonbreeding activities[edit] Outside of the breeding season, males migrate to the northern ends of the species range to feed, while females forage near the breeding rookeries.[4] Sea lions can stay at sea for as long as two weeks at a time. They make continuous dives, returning to the surface to rest. Sea lions may travel alone or in groups while at sea and haul-out between each sea trip. Adult females and juveniles molt in autumn and winter; adult males molt in January and February. Gulf of California sea lions do not migrate; they stay in the Gulf year-round.[29] Intelligence and trainability[edit] Marine biologist Ronald J. Schusterman and his research associates have studied sea lions' cognitive ability. They have discovered that sea lions are able to recognize relationships between stimuli based on similar functions or connections made with their peers, rather than only the stimuli's common features.[34] Sea lions have demonstrated the ability to understand simple syntax and commands when taught an artificial sign language. However, the sea lions rarely used the signs semantically or logically.[35] In 2011, a California sea lion named "Ronan" was recorded bobbing its head in synchronization to musical rhythms.[36] This "rhythmic entrainment" was previously seen only in humans, parrots and other birds possessing vocal mimicry.[37] Because of their intelligence and trainability, California sea lions have been used by circuses and marine mammal parks to perform various tricks such as throwing and catching balls on their noses, running up ladders, or honking horns in a musical fashion. Trainers reward their animals with fish, which motivates them to perform. For ball balancing, trainers toss a ball at a sea lion so it may accidentally balance it or hold the ball on its nose, thereby gaining an understanding of what to do. A sea lion may go through a year of training before performing a trick for the public. However, its memory allows it to perform a trick even after three months of resting.[31] Some organizations, such as the Humane Society of the United States and World Animal Protection, object to using sea lions and other marine mammals for entertainment, claiming the tricks are "exaggerated variations of their natural behaviors" and distract the audience from the animal's unnatural environment.[38] The California sea lion is used in military applications by the U.S. Navy Marine Mammal Program, including detecting naval mines and enemy divers. In the Persian Gulf, the animals can swim behind divers approaching a US naval ship and attach a clamp with a rope to the diver's leg. Navy officials say the sea lions can do this in seconds, before the enemy realizes what happened.[39] Organizations like PETA believe that such operations put the animals in danger.[40] However, the Navy insists that the sea lions are removed once their mission is complete.[41] Status[edit] The IUCN lists the California sea lion as Least Concern due to "its large and increasing population size."[1] The estimated population is 238,000–241,000 for the US or Pacific Temperate stock, 75,000–85,000 for the Western Baja California or Pacific Tropical stock, and 31,393 for the population in the Gulf of California.[7] Off the US coast, sea lions are so numerous that they are close to carrying capacity, while the Gulf of California population declined by 20% by 2008. Sea lions may be killed when in conflict with fishermen, by poaching, and by entanglements in man-made garbage. They are also threatened by pollutants like DDT and PCB which accumulate in the marine food chain.[1] In the United States, the California sea lion is protected on the Marine Mammal Protection Act (MMPA), passed in 1972, which outlaws hunting, killing, capture, and harassment of the animal. In 1994 an amendment to the Act allowed for the possibility of limited lethal removal of pinnipeds preying on endangered salmonids should the level of predation be documented to have a significant adverse impact on the decline or recovery of ESA-listed salmonids.[42] Applications have been granted for removal of several individual sea lions at Ballard Locks[43] and at the Bonneville Dam, where up to 92 sea lions can be killed each year for a 5-year period.[44] Critics have objected to the killing of the sea lions, pointing out that the level of mortality permitted as a result of recreational and commercial fisheries in the river and as part of the operation of hydroelectric dams pose a greater threat to the salmon.[45] These animals exploit more man-made environments like docks for haul-out sites. Many docks are not designed to withstand the weight of several resting sea lions which cause major tilting and other problems. Wildlife managers have used various methods to control the animals and some city officials have redesigned docks so they can better withstand them.[46][47] References[edit] - ^ a b c d Aurioles, D. & Trillmich, F. (2008). Zalophus californianus. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 30 January 2009. - ^ "California Sea Lion Management: Restoring balance between predators and salmon". Oregon Department of Fish and Wildlife. Retrieved 17 October 2013. - ^ Allen, Sarah G.; Mortenson, Joe; Webb, Sophie (2011). Field Guide to Marine Mammals of the Pacific Coast: Baja, California, Oregon, Washington, British Columbia. University of California Press. - ^ a b c d e f g h i j k l Heath, Carolyn B.; Perrin, William F. (2008). "California, Galapagos and Japanese Sea Lions Zalophus californianus, Z. wollebaeki and Z. japonicus". In Perrin, William F.; Würsig, Bernd; Thewissen, J.G.M. Encyclopedia of Marine Mammals (2nd ed.). - ^ Wolf, Jochen B.W.; Tautz, Diethard; Trillmich, Fritz (2007). "Galápagos and Californian sea lions are separate species: Genetic analysis of the genus Zalophus and its implications for conservation management". Frontiers in Zoology 4: 20. - ^ Sakahira, F.; Niimi, M. (2007). "Ancient DNA analysis of the Japanese sea lion (Zalophus californianus japonicus Peters, 1866): preliminary results using mitochondrial control-region sequences". Zoological Science 24 (1): 81–85. - ^ a b c d Schramm, Yolanda; Mesnick, S. L.; de la Rosa, J.; Palacios, D. M.; Lowry, M. S.; Aurioles-Gamboa, D.; Snell, H. M.; Escorza-Treviño, S. (2009). "Phylogeography of California and Galápagos sea lions and population structure within the California sea lion". Marine Biology 156 (7): 1375–1387. - ^ a b c d e f g h Reeves, Randall R.; Stewart, Brent S.; Clapham, Phillip J.; Powell, James A. (2002). National Audubon Society Guide to Marine Mammals of the World. Alfred A. 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Retrieved 23 May 2012. - ^ Kay, Jane (10 February 2012). "When good fishing trips go bad: Sea lion swims the Delta – lands on Merced County farm road". San Francisco Chronicle. Retrieved 3 July 2012. - ^ "Sea Lion Diet". Southwest Fisheries Science Center. Retrieved 2 September 2007. The Pinnipeds: Seals, Sea lions, and Walruses. University of California Press. - ^ Weise, Michael J.; Costa, Daniel P.; Kudela, Raphael M. (2006). "Movement and diving behavior of male California sea lion (Zalophus californianus) during anomalous oceanographic conditions of 2005 compared to those of 2004". Geophysical Research Letters 33 (L22S10). - ^ Ternullo, Richard; Black, Nancy. "Predation Behavior of Transient Killer Whales in Monterey Bay, California". Monterey Bay Whale Watch. Retrieved 23 May 2012. - ^ Baird, Robin W.; Stacey, Pam J. (1989). "Observations on the reactions of sea lions, Zalophus californianus and Eumetopias jubatus, to killer whales, Orcinus orca; evidence of "prey" having a "search image" for predators". Canadian Field-Naturalist 103 (3): 426–428. Retrieved 23 May 2012. - ^ Harris, Jeffrey D.; Melin, Sharon R.; DeLong, Robert L. "Shark-inflicted Lesions on California Sea Lions (Zalophus californianus) at San Miguel Island, California: a New Phenomenon". National Marine Mammal Laboratory – Alaska Fisheries Science Center. Retrieved 23 May 2012. - ^ Long, Douglas J.; Hanni, Krista D.; Pyle, Peter; Roletto, Jan; Jones, Robert E.; Bandar, Raymond (1995). "White Shark Predation on Four Pinniped Species in Central California Waters: Geographic and Temporal Patterns Inferred from Wounded Carcasses". In Klimley, A. Peter; Ainley, David G. Great White Sharks: The Biology of Carcharodon carcharias. Academic Press. "The Fight to Mate: Breeding strategy of California sea lions". In MacDonald, David. 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Humane Society of the United States and World Animal Protection. Retrieved 30 May 2012. - ^ Leinwand, Donna (17 February 2003). "Sea lions called to duty in Persian Gulf". USA Today. Retrieved 28 April 2010. - ^ Kreider, R. (May 31, 2011). "The Real Navy Seals – and Sea Lions and Dolphins and Whales". ABC News. Retrieved July 30, 2013. - ^ "Frequently Asked Questions". U.S. Navy Marine Mammal Program. Retrieved July 30, 2013. Reg. - ^ "NOAA authorizes states to remove sea lions that threaten protected salmon". National Oceanic and Atmospheric Administration. Retrieved 17 October 2013. - ^ "Bonneville Dam Sea Lions Under Siege". The Humane Society of the United States. Retrieved 17 October 2013. - ^ French, C. (April 10, 2013). "Sea Lions Take Over Ventura Docks". the Log.com. Retrieved August 17, 2013. - ^ Bruscas, A. (July 27, 2012). "Shocking new idea for sea lion control". The Daily World.com. Retrieved August 17, 2013. External links[edit] - Media related to Zalophus californianus at Wikimedia Commons - Data related to Zalophus californianus at Wikispecies - "Zalophus californianus". Integrated Taxonomic Information System. Retrieved 23 March 2006. - WDFW Fact Sheet on sea lions - USACE information on sea lion deterrents - Animal Diversity Web – Zalophus californianus - Smithsonian Institution – North American Mammals: Zalophus californianus - Voices in the Sea - Sounds of the California Sea Lion - IUCN Red List least concern species - Eared seals - Western North American coastal fauna - Mammals of Canada - Mammals of Mexico - Mammals of the United States - Fauna of the Western United States - Fauna of the Baja California peninsula - Fauna of Gulf of California islands - Fauna of California - Megafauna of North America - Animals described in 1828 - Urban animals