Marine Mammals
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Marine Mammals
Marine mammals are mammals that rely on marine ecosystems for their existence. They include animals such as cetaceans, pinnipeds, sirenians, sea otters and polar bears. They are an informal group, unified only by their reliance on marine environments for feeding and survival. Marine mammal adaptation to an aquatic lifestyle varies considerably between species. Both cetaceans and sirenians are fully aquatic and therefore are obligate water dwellers. Pinnipeds are semiaquatic; they spend the majority of their time in the water but need to return to land for important activities such as mating, breeding and molting. Sea otters tend to live in kelp forests and estuaries. In contrast, the polar bear is mostly terrestrial and only go into the water on occasions of necessity, and are thus much less adapted to aquatic living. The diets of marine mammals vary considerably as well; some eat zooplankton, others eat fish, squid, shellfish, or seagrass, and a few eat other mammals. Wh ...
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Mammal
A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three Evolution of mammalian auditory ossicles, middle ear bones. These characteristics distinguish them from reptiles and birds, from which their ancestors Genetic divergence, diverged in the Carboniferous Period over 300 million years ago. Around 6,640 Neontology#Extant taxon, extant species of mammals have been described and divided into 27 Order (biology), orders. The study of mammals is called mammalogy. The largest orders of mammals, by number of species, are the rodents, bats, and eulipotyphlans (including hedgehogs, Mole (animal), moles and shrews). The next three are the primates (including humans, monkeys and lemurs), the Artiodactyl, even-toed ungulates (including pigs, camels, and whales), and the Carnivora (including Felidae, ...
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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 six species of sea lions. Its natural habitat ranges from southeast Alaska to central Mexico, including the Gulf of California. California sea lions are Sexual dimorphism, sexually dimorphic; males are larger than females, and have a thicker neck, and a protruding sagittal crest. They mainly Hauling-out, haul out on sandy or rocky beaches, but they also frequent manmade environments such as marinas and Wharf, wharves. California sea lions feed on a number of species of fish and squid, and are preyed on by orcas and great white sharks. California sea lions have a Polygyny in animals, polygynous breeding pattern. From May to August, males establish territory (animal), territories and try to attract females with which to mate. Females are free to move in between territories, and are not coerced by males. Mothers nurse their pups in between foraging trips. Califo ...
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Pinniped
Pinnipeds (pronounced ), commonly known as seals, are a widely range (biology), distributed and diverse clade of carnivorous, fin-footed, semiaquatic, mostly marine mammals. They comprise the extant taxon, extant families Odobenidae (whose only living member is the walrus), Otariidae (the eared seals: sea lions and fur seals), and Phocidae (the earless seals, or true seals), with 34 extant species and more than 50 extinct species described from fossils. While seals were historically thought to have descended from two ancestral lines, molecular phylogenetics, molecular evidence supports them as a monophyletic group (descended from one ancestor). Pinnipeds belong to the suborder Caniformia of the order Carnivora; their closest living relatives are musteloids (Mustelidae, weasels, Procyonidae, raccoons, skunks and red pandas), having diverged about 50 million years ago. Seals range in size from the and Baikal seal to the and southern elephant seal. Several species exhibit ...
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Hydrurga Leptonyx Edit1
The leopard seal (''Hydrurga leptonyx''), also referred to as the sea leopard, is the second largest species of seal in the Antarctic (after the southern elephant seal). It is a top order predator, feeding on a wide range of prey including cephalopods, other pinnipeds, krill, fish, and birds, particularly penguins, and its only natural predator being the orca. It is the only species in the genus ''Hydrurga''. Its closest relatives are the Ross seal, the crabeater seal and the Weddell seal, which are all Antarctic seals of the tribe Lobodontini. Research history and taxonomy Henri Marie Ducrotay de Blainville, a French zoologist, described the leopard seal in 1820 from a stuffed specimen from the collection of one M. Hauville, in Le Havre. The skin that produced this work of taxidermy was sourced from "the southern seas", that he ascertained to be from around the Falkland Islands. Blainville describes the specimen as "beautiful", 7-8 "pieds" long ( long) and elongated, the f ...
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Aboriginal Whaling
Aboriginal whaling or indigenous whaling is the hunting of whales by indigenous peoples recognised by either IWC (International Whaling Commission) or the hunting is considered as part of indigenous activity by the country. It is permitted under international regulation, but in some countries remains a contentious issue. (The hunting of smaller cetaceans is covered at Dolphin drive hunting.) It is usually considered part of the subsistence economy. In some places, whaling has been superseded by whale watching instead. This article deals with communities that continue to hunt; details about communities that have ended the practice may be found in History of whaling. International regulation Under the terms of the 1986 moratorium, the International Whaling Commission allows the activity to be carried out by aboriginal groups if it occurs on a subsistence basis, similar to subsistence fishing. This Aboriginal Subsistence Whaling is restricted to native peoples and others working ...
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Habitat Degradation
Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease in biodiversity and species numbers. Habitat destruction is in fact the leading cause of biodiversity loss and species extinction worldwide. Humans contribute to habitat destruction through the use of natural resources, agriculture, industrial production and urbanization (urban sprawl). Other activities include mining, logging and trawling. Environmental factors can contribute to habitat destruction more indirectly. Geological processes, climate change, introduction of invasive species, ecosystem nutrient depletion, water and noise pollution are some examples. Loss of habitat can be preceded by an initial habitat fragmentation. Fragmentation and loss of habitat have become one of the most important topics of research in ecology as t ...
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North Atlantic Right Whale
The North Atlantic right whale (''Eubalaena glacialis'') is a baleen whale, one of three right whale species belonging to the genus ''Eubalaena'', all of which were formerly classified as a single species. Because of their docile nature, their slow surface-skimming feeding behaviors, their tendencies to stay close to the coast, and their high blubber content (which makes them float when they are killed, and which produces high yields of whale oil), right whales were once a preferred target for whalers. At present, they are among the most endangered whales in the world, and they are protected under the U.S. Endangered Species Act and Marine Mammal Protection Act of 1972, Marine Mammal Protection Act and Canada's Species at Risk Act. There are an estimated 356 individuals in existence in the western North Atlantic Ocean—they migrate between feeding grounds in the Labrador Sea and their winter calving areas off Georgia (U.S. state), Georgia and Florida, an ocean area with heavy ship ...
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Critically Endangered
An IUCN Red List critically endangered (CR or sometimes CE) species is one that has been categorized by the International Union for Conservation of Nature as facing an extremely high risk of extinction in the wild. As of December 2023, of the 157,190 species currently on the IUCN Red List, 9,760 of those are listed as critically endangered, with 1,302 being possibly extinct and 67 possibly extinct in the wild. The IUCN Red List provides the public with information regarding the conservation status of animal, fungi, and plant species. It divides various species into seven different categories of conservation that are based on habitat range, population size, habitat, threats, etc. Each category represents a different level of global extinction risk. Species that are considered to be critically endangered are placed within the "Threatened" category. As the IUCN Red List does not consider a species extinct until extensive targeted surveys have been conducted, species that a ...
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Bycatch
Bycatch (or by-catch), in the fishing industry, is a fish or other marine species that is caught unintentionally while fishing for specific species or sizes of wildlife. Bycatch is either the wrong species, the wrong sex, or is undersized or juveniles of the target species. The term "bycatch" is also sometimes used for untargeted catch in other forms of animal harvesting or collecting. Non- marine species ( freshwater fish not saltwater fish) that are caught (either intentionally or unintentionally) but regarded as generally "undesirable" are referred to as rough fish (mainly US) or coarse fish (mainly UK). In 1997, the Organisation for Economic Co-operation and Development (OECD) defined bycatch as "total fishing mortality, excluding that accounted directly by the retained catch of target species". Bycatch contributes to fishery decline and is a mechanism of overfishing for unintentional catch. The average annual bycatch rate of pinnipeds and cetaceans in the US from 1990 t ...
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Humpback Whale Underwater Shot
Humpback may refer to: * Humpback whale * Humpback dolphin * Humpback salmon * Humpback bridge * Humpback, a common name for the fish '' Chanodichthys dabryi'' * Humpback, a variant of hunchback Kyphosis () is an abnormally excessive convex curvature of the spine as it occurs in the thoracic and sacral regions. Abnormal inward concave ''lordotic'' curving of the cervical and lumbar regions of the spine is called lordosis. It can ..., a syndrome experienced by humans * Hump Back (Japanese band), a three-member all-female Japanese rock band {{disambiguation, fish Animal common name disambiguation pages ...
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Noise Pollution
Noise pollution, or sound pollution, is the propagation of noise or sound with potential harmful effects on humans and animals. The source of outdoor noise worldwide is mainly caused by machines, transport and propagation systems.Senate Public Works Committee. ''Noise Pollution and Abatement Act of 1972''. S. Rep. No. 1160, 92nd Congress. 2nd session Poor urban planning may give rise to noise disintegration or pollution, side-by-side industrial, and residential buildings can result in noise pollution in the residential areas. Some of the main sources of noise in residential areas include loud music, transportation (traffic, rail, airplanes, etc.), lawn care maintenance, construction, electrical generators, wind turbines, explosions, and people. Documented problems associated with noise in urban environments go back as far as ancient Rome. Research suggests that noise pollution in the United States is the highest in low-income and racial minority neighborhoods, and noise pollut ...
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Animal Echolocation
Echolocation, also called bio sonar, is a biological active sonar used by several animal groups, both in the air and underwater. Echolocating animals emit calls and listen to the Echo (phenomenon) , echoes of those calls that return from various objects near them. They use these echoes to locate and identify the objects. Echolocation is used for animal navigation , navigation, foraging, and predation, hunting prey. Echolocation calls can be Frequency modulation, frequency modulated (FM, varying in pitch during the call) or constant frequency (CF). FM offers precise range discrimination to localize the prey, at the cost of reduced operational range. CF allows both the prey's velocity and its movements to be detected by means of the Doppler effect. FM may be best for close, cluttered environments, while CF may be better in open environments or for hunting while perched. Echolocating animals include mammals, especially odontocetes (toothed whales) and some bat species, and, using s ...
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