Wingspan in the context of "Wingtip vortices"

Arm span or reach (sometimes referred to as wingspan, or spelled armspan) is the physical measurement of the length from one end of an individual's arms (measured at the fingertips) to the other when raised parallel to the ground at shoulder height at a 90° angle. The arm span measurement is usually very close to the person's height. Age, sex, and ethnicity have to be taken into account to best predict height from arm span. Arm span is sometimes used when a height measurement is needed but the individual cannot stand on a traditional stadiometer or against a wall due to abnormalities of the back or legs, such as scoliosis, osteoporosis, amputations, or those who are confined to a bed or wheelchair. Other, possibly more accurate measuring techniques include knee length or recumbent length when possible.

Because any decrease in height will cause an increase in the ratio of arm span to height, a large span to height ratio may sometimes be an indicator of a health problem that caused a vertical height loss such as postural changes due to ageing or any spinal conditions such as degenerative disc disease.

The California condor (Gymnogyps californianus) is a New World vulture and the largest North American land bird. It became extinct in the wild in 1987 when all remaining wild individuals were captured, but has since been reintroduced to northern Arizona and southern Utah (including the Grand Canyon area and Zion National Park), the coastal mountains of California, and northern Baja California in Mexico. It is the only surviving member of the genus Gymnogyps, although four extinct members of the genus are also known. The species is listed by the International Union for the Conservation of Nature as Critically Endangered, and similarly considered Critically Imperiled by NatureServe.

The plumage is black with patches of white on the underside of the wings; the head is largely bald, with skin color ranging from gray on young birds to yellow and bright orange on breeding adults. Its 3.0 m (9.8 ft) wingspan is the widest of any North American bird, and its weight of up to 12 kg (26 lb) nearly equals that of the trumpeter swan, the heaviest among native North American bird species. The condor is a scavenger and eats large amounts of carrion. It is one of the world's longest-living birds, with a lifespan of up to 60 years.

The Arctic tern (Sterna paradisaea) is a tern in the family Laridae. This bird has a circumpolar breeding distribution covering the Arctic and sub-Arctic regions of Europe (as far south as Brittany), Asia, and North America (as far south as Massachusetts). The species is strongly migratory, seeing two summers each year as it migrates along a convoluted route from its northern breeding grounds to the Antarctic coast for the southern summer and back again about six months later. Recent studies have shown average annual round-trip lengths of about 70,900 km (38,300 nmi) for birds nesting in Iceland and Greenland, and about 48,700 km (26,300 nmi) for birds nesting in the Netherlands, while an individual from the Farne Islands in Northumberland with a light level geolocator tag covered a staggering 96,000 km (52,000 nmi) in ten months from the end of one breeding season to the start of the next. These are by far the longest migrations known in the animal kingdom.

Arctic terns are medium-sized birds. They have a length of 28–39 cm (11–15 in) and a wingspan of 65–77 cm (26–30 in), and weigh around 100 g. In the breeding season they are mainly grey and white plumaged, with a blood red beak and feet, a black crown and nape, and white cheeks. The mantle is grey, and the scapulars grey, tipped white. The upper wing is grey with a white leading edge and a narrow blackish trailing edge on the primary feathers; the collar is completely white, as is the rump. The deeply forked tail is whitish, with grey outer webs. In winter, the forehead becomes partly white, and the bill and legs are black. Juveniles also have a partly white forehead, and narrow pale orangey-brown fringes on the grey mantle feathers (unlike common tern, where the mantle feathers are more completely gingery-brown).

The luna moth (Actias luna), also called the American moon moth, is a Nearctic moth in the family Saturniidae, subfamily Saturniinae, a group commonly named the giant silk moths.

The moth has lime-green wings and a white body. Its caterpillars are also green. Its typical wingspan is roughly 114 mm (4.5 in), but wingspans can exceed 178 mm (7.0 in), ranking the species as one of the larger moths found in North America.

Arambourgiania (meaning "Camille Arambourg's") is a genus of pterosaur, an extinct group of flying reptiles, that inhabited Jordan during the Maastrichtian age of the Cretaceous period, around 72 to 66 million years ago. Additional fossil remains from the United States and Morocco have also been found, but their assignment to Arambourgiania is only tentative. The holotype (name-bearing) specimen was discovered in 1943 by a railway worker near Russeifa, Jordan. After examination of the specimen by paleontologist Camille Arambourg, he described it as belonging to a new genus and species in 1959, Titanopteryx philadelphiae. The generic name means "titan wing", as the fossil was initially misidentified as a wing metacarpal (it would be later identified as a cervical (neck) vertebra), while the specific name refers to the ancient name of Amman (the capital of Jordan), Philadelphia. The genus name "Titanopteryx" would later be problematic, as it had already been taken by a fly. Because of this, paleontologist Lev Nessov in 1989 renamed the genus to Arambourgiania, in honor of Arambourg. Since 1943, additional isolated remains including vertebrae, wing bones, and hindlimb bones have been assigned to the genus.

Due to the fragmentary nature of the Arambourgiania fossils, there is little direct information about its anatomy. Its cervical vertebrae are extremely elongated, with the holotype vertebra measuring 77–78 cm (2 ft 6.31 in – 2 ft 6.71 in) in length. Based on the complete neck of its relative Quetzalcoatlus, Arambourgiania had a total neck length of 3 m (9 ft 10 in), longer than those of giraffes. Its vertebrae were also more lightly built and weakly muscled than those of its robust, short-necked relative Hatzegopteryx. Arambourgiania is one of the largest flying animals ever discovered. Initial wingspan estimates ranged from 11 to 13 m (36 to 43 ft), which would have made it the largest known pterosaur. However, given the fragmentary remains, more recent research has suggested wingspans anywhere between 8 to 10 m (26 to 33 ft), which would still place the genus among the largest known flying animals.

Lift-induced drag, induced drag, vortex drag, or sometimes drag due to lift, in aerodynamics, is an aerodynamic drag force that occurs whenever a moving object redirects the airflow coming at it. This drag force occurs in airplanes due to wings or a lifting body redirecting air to cause lift and also in cars with airfoil wings that redirect air to cause a downforce. It is symbolized as ${\textstyle D_{\text{i}}}$, and the lift-induced drag coefficient as ${\textstyle C_{D,i}}$.

For a constant amount of lift, induced drag can be reduced by increasing airspeed. A counter-intuitive effect of this is that, up to the speed-for-minimum-drag, aircraft need less power to fly faster. Induced drag is also reduced when the wingspan is higher, or for wings with wingtip devices.

The wedge-tailed eagle (Aquila audax), also known as the eaglehawk, is the largest bird of prey in the continent of Australia. It is also found in southern New Guinea to the north and is distributed as far south as the state of Tasmania. Adults of the species have long, broad wings, fully feathered legs, an unmistakable wedge-shaped tail, an elongated upper mandible, a strong beak and powerful feet. The wedge-tailed eagle is one of 12 species of large, predominantly dark-coloured booted eagles in the genus Aquila found worldwide. Genetic research has clearly indicated that the wedge-tailed eagle is fairly closely related to other, generally large members of the Aquila genus. A large brown-to-black bird of prey, it has a maximum reported wingspan of 2.84 m (9 ft 4 in) and a length of up to 1.06 m (3 ft 6 in).

The wedge-tailed eagle is one of its native continent's most generalised birds of prey. They reside in most habitats present in Australia, ranging from desert and semi-desert to plains to mountainous areas to forest, even sometimes tropical rainforests. Preferred habitats, however, tend towards those that have a fairly varied topography including rocky areas, some open terrain and native woodlots such as Eucalyptus stands.

The marabou stork (Leptoptilos crumenifer) is a large wading bird in the stork family Ciconiidae native to sub-Saharan Africa. It breeds in both wet and arid habitats, often near human habitation, especially landfill sites. It is sometimes called the "undertaker bird" due to its shape from behind: cloak-like wings and back, skinny white legs, and sometimes a large white mass of "hair". It has often been credited with the largest wingspan of any land bird, with an average of 2.6 metres (8.5 ft) and some recorded examples of up to 3.2 metres (10 ft).