page_title: Pinniped
section_title: Behavior and life history
hierarchical_section_title: Pinniped / Behavior and life history
caption_attribution_description: English: Phoca vitulina, or Habor Seal, at Point Lobos State Reserve near Monterrey in California, United States.
context_page_description: Pinnipeds, commonly known as seals, are a widely distributed and diverse clade of carnivorous, fin-footed, semiaquatic marine mammals. They comprise the extant families Odobenidae, Otariidae, and Phocidae. There are 33 extant species of pinnipeds, and more than 50 extinct species have been described from fossils. While seals were historically thought to have descended from two ancestral lines, molecular evidence supports them as a monophyletic lineage. Pinnipeds belong to the order Carnivora and their closest living relatives are bears and the superfamily of musteloids, having diverged about 50 million years ago.
  Seals range in size from the 1 m and 45 kg Baikal seal to the 5 m and 3,200 kg southern elephant seal male, which is also the largest member of the order Carnivora. Several species exhibit sexual dimorphism. They have streamlined bodies and four limbs that are modified into flippers. Though not as fast in the water as dolphins, seals are more flexible and agile. Otariids use their front limbs primarily to propel themselves through the water, while phocids and walruses use their hind limbs.
context_section_description: Pinnipeds have an amphibious lifestyle; they spend most of their lives in the water, but haul out to mate, raise young, molt, rest, thermoregulate or escape from aquatic predators. Several species are known to migrate vast distances, particularly in response to extreme environmental changes, like El Niño or changes in ice cover. Elephant seals stay at sea 8–10 months a year and migrate between breeding and molting sites. The northern elephant seal has one of the longest recorded migration distances for a mammal, at 18,000–21,000 km (11,000–13,000 mi). Phocids tend to migrate more than otariids. Traveling seals may use various features of their environment to reach their destination including geomagnetic fields, water and wind currents, the position of the sun and moon and the taste and temperature of the water.
  Pinnipeds may dive during foraging or to avoid predators. When foraging, Weddell seals typically dive for less than 15 minutes to depths of around 400 m (1,300 ft) but can dive for as long as 73 minutes and to depths of up to 600 m (2,000 ft). Northern elephant seals commonly dive 350–650 m (1,150–2,130 ft) for as long as 20 minutes. They can also dive 1,259–4,100 m (4,131–13,451 ft) and for as long as 62 minutes. The dives of otariids tend to be shorter and less deep. They typically last 5–7 minutes with average depths to 30–45 m (98–148 ft). However, the New Zealand sea lion has been recorded diving to a maximum of 460 m (1,510 ft) and a duration of 12 minutes. Walruses do not often dive very deep, as they feed in shallow water.
  Pinnipeds have lifespans averaging 25–30 years. Females usually live longer, as males tend to fight and often die before reaching maturity. The longest recorded lifespans include 43 years for a wild female ringed seal and 46 years for a wild female grey seal. The age at which a pinniped sexually matures can vary from 2–12 years depending on the species. Females typically mature earlier than males.
caption: Harbor seal hauled out on rock
exif: {"Image Make": "Canon", "Image Model": "Canon EOS 5D Mark III", "Image XResolution": "240", "Image YResolution": "240", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Adobe Photoshop Lightroom 4.4 (Windows)", "Image DateTime": "2013:05:28 09:11:30", "Image ExifOffset": "214", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "860", "Thumbnail JPEGInterchangeFormatLength": "21268", "EXIF ExposureTime": "1/320", "EXIF FNumber": "8", "EXIF ExposureProgram": "Aperture Priority", "EXIF ISOSpeedRatings": "400", "EXIF SensitivityType": "Recommended Exposure Index", "EXIF RecommendedExposureIndex": "400", "EXIF ExifVersion": "0230", "EXIF DateTimeOriginal": "2013:05:20 14:42:14", "EXIF DateTimeDigitized": "2013:05:20 14:42:14", "EXIF ShutterSpeedValue": "1040241/125000", "EXIF ApertureValue": "6", "EXIF ExposureBiasValue": "1/3", "EXIF MaxApertureValue": "5", "EXIF MeteringMode": "CenterWeightedAverage", "EXIF Flash": "Flash did not fire, compulsory flash mode", "EXIF FocalLength": "300", "EXIF SubSecTimeOriginal": "81", "EXIF SubSecTimeDigitized": "81", "EXIF FocalPlaneXResolution": "160", "EXIF FocalPlaneYResolution": "160", "EXIF FocalPlaneResolutionUnit": "4", "EXIF CustomRendered": "Normal", "EXIF ExposureMode": "Auto Exposure", "EXIF WhiteBalance": "Auto", "EXIF SceneCaptureType": "Standard", "EXIF BodySerialNumber": "028021003087", "EXIF LensSpecification": "[70, 300, 0/0, 0/0]", "EXIF LensModel": "EF70-300mm f/4-5.6L IS USM", "EXIF LensSerialNumber": "8340000358"}