"evidence. Seabirds fly low over water but gain altitude when crossing land, and the reverse pattern is seen in landbirds. However most bird migration is in the range of . Bird strike aviation records from the United States show most collisions occur below and almost none above . Bird migration is not limited to birds that can fly. Most species of penguin (Spheniscidae) migrate by swimming. These routes can cover over . Dusky grouse ""Dendragapus obscurus"" perform altitudinal migration mostly by walking. Emus ""Dromaius novaehollandiae"" in Australia have been observed to undertake long-distance movements on foot during droughts. While participating"
"Flightless cormorant The flightless cormorant (""Phalacrocorax harrisi""), also known as the Galapagos cormorant, is a cormorant native to the Galapagos Islands, and an example of the highly unusual fauna there. It is unique in that it is the only cormorant that has lost the ability to fly. Once it was placed in its own genus, ""Nannopterum"" or ""Compsohalieus"", although current taxonomy places it in the genus with most of the other cormorants, ""Phalacrocorax"". Like all cormorants, this bird has webbed feet and powerful legs that propel it through ocean waters as it seeks its prey of fish, eels, small octopuses,"
"Penguin Penguins (order Sphenisciformes, family Spheniscidae) are a group of aquatic, flightless birds. They live almost exclusively in the Southern Hemisphere, with only one species, the Galapagos penguin, found north of the equator. Highly adapted for life in the water, penguins have countershaded dark and white plumage, and their wings have evolved into flippers. Most penguins feed on krill, fish, squid and other forms of sea life which they catch while swimming underwater. They spend roughly half of their lives on land and the other half in the sea. Although almost all penguin species are native to the Southern Hemisphere,"
"within the species range, and the prevention of fishing with nets in the bird's foraging range. Flightless cormorant The flightless cormorant (""Phalacrocorax harrisi""), also known as the Galapagos cormorant, is a cormorant native to the Galapagos Islands, and an example of the highly unusual fauna there. It is unique in that it is the only cormorant that has lost the ability to fly. Once it was placed in its own genus, ""Nannopterum"" or ""Compsohalieus"", although current taxonomy places it in the genus with most of the other cormorants, ""Phalacrocorax"". Like all cormorants, this bird has webbed feet and powerful legs"
"on one side with the middle on the other side. Insects are the only invertebrates to have evolved flight, and all flying insects derive from one common ancestor. Many insects spend at least part of their lives under water, with larval adaptations that include gills, and some adult insects are aquatic and have adaptations for swimming. Some species, such as water striders, are capable of walking on the surface of water. Insects are mostly solitary, but some, such as certain bees, ants and termites, are social and live in large, well-organized colonies. Some insects, such as earwigs, show maternal care,"
"very disparate morphological requirements. As a result, despite the large diversity of animals that are capable of flight or swimming, only a limited number of these species have mastered the ability to both fly and swim. These species demonstrate distinct morphological and behavioral tradeoffs associated with transitioning from air to water and water to air. Of extant species, only insects, birds, and bats are capable of true, sustained, powered flight. For birds to achieve flight, they must first successfully overcome the downward pull of gravitational forces by producing lift. According to Bernoulli's Principle, a faster moving fluid produces reduced pressure"
"gliding: Bats are the only mammal with flapping or powered flight. A few other mammals glide or parachute; the best known are flying squirrels and flying lemurs. Flying and gliding animals A number of animals have evolved aerial locomotion, either by powered flight or by gliding. Flying and gliding animals (""volant"" animals) have evolved separately many times, without any single ancestor. Flight has evolved at least four times, in the insects, pterosaurs, birds, and bats. Gliding has evolved on many more occasions. Usually the development is to aid canopy animals in getting from tree to tree, although there are other"
"also included here. Flightless bird Flightless birds are birds that through evolution lost the ability to fly. There are over 60 extant species including the well known ratites (ostrich, emu, cassowary, rhea and kiwi) and penguins. The smallest flightless bird is the Inaccessible Island rail (length 12.5 cm, weight 34.7 g). The largest (both heaviest and tallest) flightless bird, which is also the largest living bird, is the ostrich (2.7 m, 156 kg). Ostriches are farmed for their decorative feathers, meat and their skins, which are used to make leather. Many domesticated birds, such as the domestic chicken and domestic"
"field since they occupy the same habitat and, although the flying steamer duck can fly, it rarely does. Charles Darwin devoted two paragraphs to this bird (or the similar flying steamer duck) in The Voyage of the Beagle, having observed them at the Falkland Islands in 1833: Falkland steamer duck The Falkland steamer duck (""Tachyeres brachypterus"") is a steamer duck native to the Falkland Islands in the southern Atlantic Ocean. It is one of only two bird species to be endemic to the Falkland Islands, the other being Cobb's wren. The Falkland steamer duck's wings are very short (hence the"
"Water opossum The water opossum (""Chironectes minimus""), also locally known as the yapok (), is a marsupial of the family Didelphidae. It is the only living member of its genus, Chironectes. This semiaquatic creature is found in and near the freshwater streams and lakes in Mexico, Central, South America to Argentina and is the most aquatic living marsupial (the lutrine opossum also has aquatic habits). It is also the only living marsupial in which both sexes have a pouch. The thylacine, commonly referred to as the Tasmanian tiger, also exhibited this trait, but is now believed to be extinct. The"
"Bird Birds, also known as Aves, are a group of endothermic vertebrates, characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton. Birds live worldwide and range in size from the bee hummingbird to the ostrich. They rank as the world's most numerically-successful class of tetrapods, with approximately ten thousand living species, more than half of these being passerines, sometimes known as perching birds. Birds have which are more or less developed depending on the species; the only known groups without wings are the extinct moa"
"Flightless bird Flightless birds are birds that through evolution lost the ability to fly. There are over 60 extant species including the well known ratites (ostrich, emu, cassowary, rhea and kiwi) and penguins. The smallest flightless bird is the Inaccessible Island rail (length 12.5 cm, weight 34.7 g). The largest (both heaviest and tallest) flightless bird, which is also the largest living bird, is the ostrich (2.7 m, 156 kg). Ostriches are farmed for their decorative feathers, meat and their skins, which are used to make leather. Many domesticated birds, such as the domestic chicken and domestic duck, have lost"
"absent in diving birds. For example, in the long-tailed duck, the leg and wing bones are not pneumatic, in contrast with some of the other bones, while loonsand puffins have even more massive skeletons with no aired bones. The flightless ostrich and emu have pneumatic femurs, and so far this is the only known pneumatic bone in these birds except for the ostrich's cervical vertebrae. Fusions (leading to rigidity) and pneumatic bones (leading to reduced mass) are some of the many adaptations of birds for flight. Most birds, except loons and grebes, are digitigrade, not plantigrade. Also, chicks in the"
"Grebe A grebe () is a member of the order Podicipediformes and the only type of bird associated with this order. Grebes are a widely distributed order of freshwater diving birds, some of which visit the sea when migrating and in winter. This order contains only a single family, the Podicipedidae, containing 22 species in six extant genera. Grebes are small to medium-large in size, have lobed toes, and are excellent swimmers and divers. Although they can run for a short distance, they are prone to falling over, since they have their feet placed far back on the body. Grebes"
"surface, as some of the storm-petrels do. Many of these do not ever land in the water, and some, such as the frigatebirds, have difficulty getting airborne again should they do so. Another seabird family that does not land while feeding is the skimmer, which has a unique fishing method: flying along the surface with the lower mandible in the water—this shuts automatically when the bill touches something in the water. The skimmer's bill reflects its unusual lifestyle, with the lower mandible uniquely being longer than the upper one. Surface feeders that swim often have unique bills as well, adapted"
"often observed in swimming birds during the foraging (or bottom) phase of a dive because it provides greater maneuverability for pursuing prey while the more efficient lift based swimming mechanisms are used during descent. Guillemots were observed to use lift based swimming intermittently during the ascent phase of a dive but rely mostly on passive buoyancy forces to lift them to the surface. Some examples of birds that have lost the ability to fly in favor of an aquatic lifestyle include: The transition of predominantly swimming locomotion directly to flight has evolved in a single family of marine fish called"
"Some reptiles are more closely related to birds than other reptiles, and many scientists prefer to make Reptilia a monophyletic group which includes the birds. Extant non-avian reptiles which inhabit or frequent the sea include sea turtles, sea snakes, terrapins, the marine iguana, and the saltwater crocodile. Currently, of the approximately 12,000 extant reptile species and sub-species, only about 100 of are classed as marine reptiles. Unlike amphibians, reptiles do not have an aquatic larval stage. Most reptiles are oviparous, although several species of squamates are viviparous, as were some extinct aquatic clades — the fetus develops within the mother,"
"Platypus The platypus (""Ornithorhynchus anatinus""), sometimes referred to as the duck-billed platypus, is a semiaquatic egg-laying mammal endemic to eastern Australia, including Tasmania. Together with the four species of echidna, it is one of the five extant species of monotremes, the only mammals that lay eggs instead of giving birth to live young. The animal is the sole living representative of its family (Ornithorhynchidae) and genus (""Ornithorhynchus""), though a number of related species appear in the fossil record. The first scientists to examine a preserved platypus body (in 1799) judged it a fake, made of several animals sewn together. The"
"United States Gulf Coast populations in Louisiana and Texas are still listed as endangered, they were recently estimated at about 12,000 breeding pairs. Brown pelican The brown pelican (""Pelecanus occidentalis"") is a North American bird of the pelican family, Pelecanidae. It is one of three pelican species found in the Americas and one of only two that feed by diving in water. It is found on the Atlantic Coast from Nova Scotia to the mouth of the Amazon River, and along the Pacific Coast from British Columbia to northern Chile, including the Galapagos Islands. The nominate subspecies in its breeding"
"cold is kept out by a dense layer of down feathers. The cormorants possess a layer of unique feathers that retain a smaller layer of air (compared to other diving birds) but otherwise soak up water. This allows them to swim without fighting the buoyancy that retaining air in the feathers causes, yet retain enough air to prevent the bird losing excessive heat through contact with water. The plumage of most seabirds is less colourful than that of land birds, restricted in the main to variations of black, white or grey. A few species sport colourful plumes (such as the"
"to that of grebes or coots, that they use to propel themselves in the water. They are reclusive birds, preferring in well-covered slow-flowing streams and secluded waterways, sometimes swimming partly submerged, like an Anhinga. Sungrebes are unique among birds in that males have ""pouches"", folds of skin under their wings in which they carry their young from hatching until the chicks are able to swim for themselves. This has led to them being called ""Marsupial Birds"" Female: A small, slim bird, averaging about 30cm long. Sungrebes have lobed toes, and the bare skin of their feet and legs are boldly"
"Flying gurnard The flying gurnard (""Dactylopterus volitans""), also known as the helmet gurnard, is a bottom-dwelling fish of tropical to warm temperate waters on both sides of the Atlantic Ocean. On the American side, it is found as far north as Massachusetts (exceptionally as far as Canada) and as far south as Argentina, including the Caribbean and Gulf of Mexico. On the European and African side, it ranges from the English Channel to Angola, including the Mediterranean. This is the only species in the monotypic genus Dactylopterus. Similar and related species from the genus ""Dactyloptena"" are found in the Indian"
"a bird that is called a frigatebird, which makes the boobies throw up what they eat in order to eat it herself, and she does not sustain herself on anything else. It is a seabird, but does not alight on the sea nor depart from land 20 leagues. There are many of these on the islands of Cape Verde. In the 15th century text the name of the bird is written as ""rabiforçado"". The modern Spanish word for a frigatebird is ""rabihorcado"" or ""forked tail"". A population of magnificent frigatebirds once bred on the Cape Verde Islands but is now"
"than walks. It can swim when pressed to do so by pursuit from predators. Captive birds have been recorded diving and swimming short distances under water. Most house sparrows do not move more than a few kilometres during their lifetimes. However, limited migration occurs in all regions. Some young birds disperse long distances, especially on coasts, and mountain birds move to lower elevations in winter. Two subspecies, ""P. d. bactrianus"" and ""P. d. parkini"", are predominantly migratory. Unlike the birds in sedentary populations that migrate, birds of migratory subspecies prepare for migration by putting on weight. House sparrows can breed"
"seals and otters, and birds such as penguins. Many species of snakes are also aquatic and live their entire lives in the water. Among invertebrates, a number of insect species have adaptations for aquatic life and locomotion. Examples of aquatic insects include dragonfly larvae, water boatmen, and diving beetles. There are also aquatic spiders, although they tend to prefer other modes of locomotion under water than swimming proper. Even though primarily terrestrial tetrapods have lost many of their adaptations to swimming, the ability to swim has been preserved or re-developed in many of them. It may never have been completely"
"Diving bird Diving birds are birds which plunge into water to catch fish or other food. They may enter the water from flight, as does the brown pelican (""Pelecanus occidentalis""), or they may dive from the surface of the water. More than likely they evolved from birds already adapted for swimming that were equipped with such adaptations as lobed or webbed feet for propulsion. Some diving birds - for example, the extinct Hesperornithes of the Cretaceous Period - propelled themselves with their feet. They were large, streamlined, flightless birds with teeth for grasping slippery prey. Today, cormorants (family Phalacrocoracidae), loons"
"mobility on land, in exchange for swimming ability; their wings are a compromise between the best possible design for diving and the bare minimum needed for flying. This varies by subfamily, the ""Uria"" guillemots (including the razorbill) and murrelets being the most efficient under the water, whereas the puffins and auklets are better adapted for flying and walking. The feeding behaviour of auks is often compared to that of penguins; both groups are wing-propelled pursuit divers. In the region where auks live, their only seabird competition are cormorants (which are dive-powered by their strong feet). In areas where the two"
"and their eyes do not overlap. Damselfly nymphs differ from dragonflies nymphs in that they possess caudal gills (on the abdomen) whereas dragonflies breathe through the rectum. Damselfly nymphs swim by fish-like undulations, the gills functioning like a tail. Dragonfly nymphs can forcibly expel water in their rectum for rapid escape. Odonates are found on all the continents except Antarctica. Although some species of dragonfly have wide distributions, damselflies tend to have smaller ranges. Most odonates breed in fresh-water; a few damselflies in the family Caenagrionidae breed in brackish water (and a single dragonfly species breeds in seawater). Dragonflies are"
"Anatidae The Anatidae are the biological family of birds that includes ducks, geese, and swans. The family has a cosmopolitan distribution, occurring on all the world's continents. These birds are adapted for swimming, floating on the water surface, and in some cases diving in at least shallow water. The family contains around 146 species in 43 genera. (The magpie goose is no longer considered to be part of the Anatidae and is now placed in its own family, Anseranatidae.) They are generally herbivorous, and are monogamous breeders. A number of species undertake annual migrations. A few species have been domesticated"
"Kakapo The kakapo (Māori: kākāpō) or ""night parrot"", also called owl parrot (""Strigops habroptilus""), is a species of large, flightless, nocturnal, ground-dwelling parrot of the super-family Strigopoidea, endemic to New Zealand. It has finely blotched yellow-green plumage, a distinct facial disc, a large grey beak, short legs, large feet, and relatively short wings and tail. A combination of traits make it unique among its kind; it is the world's only flightless parrot, the heaviest parrot, nocturnal, herbivorous, visibly sexually dimorphic in body size, has a low basal metabolic rate and no male parental care, and is the only parrot to"
"out of their funnel, indeed some squid have been observed to continue jetting water while airborne providing thrust even after leaving the water. This may make flying squid the only animals with jet-propelled aerial locomotion. The neon flying squid has been observed to glide for distances over 30 m, at speeds of up to 11.2 m/s. Soaring birds can maintain flight without wing flapping, using rising air currents. Many gliding birds are able to ""lock"" their extended wings by means of a specialized tendon. Soaring birds may alternate glides with periods of soaring in rising air. Five principal types of"
"Ctenophora Ctenophora (; singular ctenophore, or ; from the Greek κτείς ""kteis"" ""comb"" and φέρω ""pherō"" ""to carry""; commonly known as comb jellies) comprise a phylum of invertebrate animals that live in marine waters worldwide. They are notable for the groups of cilia they use for swimming (commonly referred to as ""combs""), and they are the largest animals to swim with the help of cilia. Depending on the species, adult ctenophores range from a few millimeters to in size. Only 100 to 150 species have been validated, and possibly another 25 have not been fully described and named. The textbook"
"can hover for a short period of time. Although not a true hover, some birds remain in a fixed position relative to the ground or water by flying into a headwind. Kestrels, terns and even hawks use this wind hovering. Most birds that hover have high aspect ratio wings that are suited to low speed flying. One major exception to this are the hummingbirds, which are the most accomplished hoverers of all the birds. Hummingbird flight is different from other bird flight in that the wing is extended throughout the whole stroke, the stroke being a symmetrical figure of eight,"