Old World monkeys and New World monkeys are two major branches of monkey evolution, and the names describe far more than geography. Old World monkeys belong to the family Cercopithecidae within Catarrhini and are native to Africa and Asia. New World monkeys belong to Platyrrhini and are native to the Americas. Their noses, teeth, tails, … Read more
Monkeys and apes are both primates, but they are not the same kind of primate. In modern classification, monkeys belong to New World or Old World monkey lineages, while apes belong to the superfamily Hominoidea. The most familiar visible clue is the tail: living apes do not have an external tail, while most monkeys do. … Read more
What makes an animal a primate is not one obvious feature. Primates are mammals that belong to a shared evolutionary branch and tend to combine several traits, including mobile hands and feet, sensitive digits, forward-facing eyes, strong depth perception, flexible limbs, and relatively long periods of growth and learning. Many also have nails on most … Read more
Primates are a diverse order of mammals that includes lemurs, lorises, galagos, tarsiers, monkeys, apes, and humans. They are not defined by one feature such as opposable thumbs, large brains, or life in trees. Instead, primates share a broad evolutionary pattern that combines flexible limbs, grasping ability in many lineages, forward-facing eyes, sensitive hands and … Read more
Marine mammal conservation is not about saving one uniform group with one conservation status. Whales, dolphins, porpoises, seals, sea lions, manatees, dugongs, and sea otters include species and populations with very different trends. Some have recovered substantially from past exploitation, while others remain at serious risk from fishing gear, vessel strikes, habitat change, underwater noise, … Read more
Marine mammal migration is the repeated movement of animals between areas that offer different seasonal advantages. A whale may leave a productive feeding ground for a warmer breeding area. A seal may spend months foraging at sea before returning to a traditional breeding colony. Arctic whales may follow shifting sea ice and openings in the … Read more
Marine mammals communicate underwater mainly through sound because sound can travel efficiently through water even when visibility is poor. Whales use calls and, in some species, songs. Dolphins and other toothed whales use whistles, burst-pulsed sounds, and clicks. Pinnipeds such as seals and sea lions can vocalize both underwater and in air, while sirenians and … Read more
Marine mammals do sleep, but they do not all solve the problem in the same way. Dolphins and other cetaceans can show unihemispheric slow-wave sleep, in which one cerebral hemisphere displays sleep-like slow waves while the other remains in a more wake-like state. Some eared seals can also use this pattern in water, yet switch … Read more
Marine mammals stay warm in cold water by controlling how quickly heat leaves the body and by producing enough metabolic heat to replace what is lost. Most whales and many seals rely heavily on blubber, sea otters depend much more on exceptionally dense fur, and many species use blood-vessel arrangements that conserve heat in flippers, … Read more
Marine mammals can spend remarkable amounts of time underwater, but they do not breathe there. Whales, dolphins, seals, sea lions, manatees, dugongs, and sea otters all use lungs and must return to the surface for air. Their diving ability comes from managing a limited oxygen supply efficiently, not from extracting oxygen from seawater. The most … Read more
