Animal locomotion
The term "locomotion" is formed in English from Latin loco "from a place" (ablative of locus "place") +
motio "motion, a moving".
Animal locomotion, in ethology, is any of a variety of methods that animals use to move from one place
to another.[1] Some modes of locomotion are (initially) self-propelled, e.g., running, swimming, jumping,
flying, hopping, soaring and gliding. There are also many animal species that depend on their
environment for transportation, a type of mobility called passive locomotion, e.g., sailing (some
jellyfish), kiting (spiders), rolling (some beetles and spiders) or riding other animals (phoresis).
Animals move for a variety of reasons, such as to find food, a mate, a suitable microhabitat, or to escape
predators. For many animals, the ability to move is essential for survival and, as a result, natural
selection has shaped the locomotion methods and mechanisms used by moving organisms. For example,
migratory animals that travel vast distances (such as the Arctic tern) typically have a locomotion
mechanism that costs very little energy per unit distance, whereas non-migratory animals that must
frequently move quickly to escape predators are likely to have energetically costly, but very fast,
locomotion.
The anatomical structures that animals use for movement, including cilia, legs, wings, arms, fins, or tails
are sometimes referred to as locomotory organs[2] or locomotory structures.[3]
https://www.britannica.com/topic/locomotion/Saltation#ref48452
Aerial
Active flight
A pair of brimstone butterflies in flight. The female, above, is in fast forward flight with a small angle of
attack; the male, below, is twisting his wings sharply upward to gain lift and fly up towards the female.
Main articles: Flight and Flying and gliding animals
Gravity is the primary obstacle to flight. Because it is impossible for any organism to have a density as
low as that of air, flying animals must generate enough lift to ascend and remain airborne. One way to
achieve this is with wings, which when moved through the air generate an upward lift force on the
animal's body. Flying animals must be very light to achieve flight, the largest living flying animals being
birds of around 20 kilograms.[23] Other structural adaptations of flying animals include reduced and
redistributed body weight, fusiform shape and powerful flight muscles;[24] there may also be
physiological adaptations.[25] Active flight has independently evolved at least four times, in the insects,
pterosaurs, birds, and bats. Insects were the first taxon to evolve flight, approximately 400 million years
ago (mya),[26] followed by pterosaurs approximately 220 mya,[27] birds approximately 160 mya,[28]
then bats about 60 mya.[29][better source needed]
Gliding
Main article: Flying and gliding animals
Rather than active flight, some (semi-) arboreal animals reduce their rate of falling by gliding. Gliding is
heavier-than-air flight without the use of thrust; the term "volplaning" also refers to this mode of flight
in animals.[30] This mode of flight involves flying a greater distance horizontally than vertically and
therefore can be distinguished from a simple descent like a parachute. Gliding has evolved on more
occasions than active flight. There are examples of gliding animals in several major taxonomic classes
such as the invertebrates (e.g., gliding ants), reptiles (e.g., banded flying snake), amphibians (e.g., flying
frog), mammals (e.g., sugar glider, squirrel glider).
Flying fish taking off
Some aquatic animals also regularly use gliding, for example, flying fish, octopus and squid. The flights of
flying fish are typically around 50 meters (160 ft),[31] though they can use updrafts at the leading edge
of waves to cover distances of up to 400 m (1,300 ft).[31][32] To glide upward out of the water, a flying
fish moves its tail up to 70 times per second.[33] Several oceanic squid, such as the Pacific flying squid,
leap out of the water to escape predators, an adaptation similar to that of flying fish.[34] Smaller squids
fly in shoals, and have been observed to cover distances as long as 50 m. Small fins towards the back of
the mantle help stabilize the motion of flight. They exit the water by expelling water 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.[35] The neon flying squid has been observed to glide for distances over 30 m, at speeds of
up to 11.2 m/s.[36]
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 possibilities. Gliding, in particular, has evolved among rainforest animals, especially in
the rainforests in Asia (most especially Borneo) where the trees are tall and widely spaced. Several
species of aquatic animals, and a few amphibians and reptiles have also evolved to acquire this gliding
flight ability, typically as a means of evading predators.
