The tail is the section at the rear end of certain kinds of
animal
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, and go through an ontogenetic stage ...
s’ bodies; in general, the term refers to a distinct, flexible
appendage to the
torso
The torso or trunk is an anatomical term for the central part, or the core, of the body of many animals (including humans), from which the head, neck, limbs, tail and other appendages extend. The tetrapod torso — including that of a hu ...
. It is the part of the body that corresponds roughly to the
sacrum and
coccyx in
mammals,
reptiles, and
bird
Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...
s. While tails are primarily a feature of
vertebrates, some
invertebrate
Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chorda ...
s including
scorpions and
springtail
Springtails (Collembola) form the largest of the three lineages of modern hexapods that are no longer considered insects (the other two are the Protura and Diplura). Although the three orders are sometimes grouped together in a class called ...
s, as well as
snail
A snail is, in loose terms, a shelled gastropod. The name is most often applied to land snails, terrestrial pulmonate gastropod molluscs. However, the common name ''snail'' is also used for most of the members of the molluscan class ...
s and
slugs, have tail-like appendages that are sometimes referred to as tails. Tailed objects are sometimes referred to as "caudate" and the part of the body associated with or proximal to the tail are given the adjective "caudal".
Function
Animal tails are used in a variety of ways. They provide a source of
locomotion for
fish
Fish are Aquatic animal, aquatic, craniate, gill-bearing animals that lack Limb (anatomy), limbs with Digit (anatomy), digits. Included in this definition are the living hagfish, lampreys, and Chondrichthyes, cartilaginous and bony fish as we ...
and some other forms of
marine life.
Many land animals use their tails to brush away
flies and other biting insects.
Most
canine
Canine may refer to:
Zoology and anatomy
* a dog-like Canid animal in the subfamily Caninae
** ''Canis'', a genus including dogs, wolves, coyotes, and jackals
** Dog, the domestic dog
* Canine tooth, in mammalian oral anatomy
People with the surn ...
s use their tails to comunicate mood and intention
. Some species, including
cats and
kangaroo
Kangaroos are four marsupials from the family Macropodidae (macropods, meaning "large foot"). In common use the term is used to describe the largest species from this family, the red kangaroo, as well as the antilopine kangaroo, eastern ...
s, use their tails for
balance;
and some, such as
monkeys and
opossums, have what are known as
prehensile tail
A prehensile tail is the tail of an animal that has adapted to grasp or hold objects. Fully prehensile tails can be used to hold and manipulate objects, and in particular to aid arboreal creatures in finding and eating food in the trees. If the t ...
s, which are adapted to allow them to grasp tree branches.
Tails are also used for social signaling. Some
deer
Deer or true deer are hoofed ruminant mammals forming the family Cervidae. The two main groups of deer are the Cervinae, including the muntjac, the elk (wapiti), the red deer, and the fallow deer; and the Capreolinae, including the re ...
species flash the white underside of their tails to warn other nearby deer of possible danger,
beavers slap the water with their tails to indicate danger,
and
canids (including domestic
dogs) indicate
emotion
Emotions are mental states brought on by neurophysiological changes, variously associated with thoughts, feelings, behavioral responses, and a degree of pleasure or displeasure. There is currently no scientific consensus on a definitio ...
s through the positioning and movement of their tails.
Some species' tails are armored, and some, such as those of
scorpions, contain
venom.
Some species of
lizard can
detach ("cast") their tails from their bodies. This can help them to escape
predators, which are either distracted by the wriggling, detached tail or left with only the tail while the lizard flees. Tails cast in this manner generally grow back over time, though the replacement is typically darker in colour than the original and contains only
cartilage, not bone.
Various species of
rat demonstrate a similar function with their tails, known as
degloving, in which the outer layer is shed in order for the animal to escape from a predator.
Most birds' tails end in long
feathers called
rectrices
Flight feathers (''Pennae volatus'') are the long, stiff, asymmetrically shaped, but symmetrically paired pennaceous feathers on the wings or tail of a bird; those on the wings are called remiges (), singular remex (), while those on the tai ...
. These feathers are used as a rudder, helping the bird steer and maneuver in
flight; they also help the bird to balance while it is perched.
In some species—such as
birds of paradise,
lyrebirds
A lyrebird is either of two species of ground-dwelling Australian birds that compose the genus ''Menura'', and the family Menuridae. They are most notable for their impressive ability to mimic natural and artificial sounds from their environm ...
, and most notably
peafowl—modified tail feathers play an important role in
courtship
Courtship is the period wherein some couples get to know each other prior to a possible marriage. Courtship traditionally may begin after a betrothal and may conclude with the celebration of marriage. A courtship may be an informal and private m ...
displays. The extra-stiff tail feathers of other species, including
woodpeckers and
woodcreeper
The woodcreepers (Dendrocolaptinae) comprise a subfamily of suboscine passerine birds endemic to the Neotropics. They have traditionally been considered a distinct family Dendrocolaptidae, but most authorities now place them as a subfamily o ...
s, allow them to brace themselves firmly against tree trunks.
The tails of grazing animals, such as
horse
The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 million yea ...
s, are used both to sweep away insects and positioned or moved in ways that indicate the animal's physical or emotional state.
Human tails
In humans,
tail bud
In humans and other mammals, the caudal cell mass (also tail bud or caudal eminence in humans) is the aggregate of undifferentiated cells at the caudal end on the spine. The caudal end of the spinal cord first begins to form after primary neurula ...
refers to the part of the
embryo which develops into the end of the spine.
However, this is not a tail.
Infrequently, a child is born with a "soft tail", which contains no vertebrae, but only
blood vessels,
muscles, and
nerves, but this is regarded as an abnormality rather than a vestigial true tail, even when such an appendage is located where the tail would be expected.
Fewer than 40 cases have been reported of infants with "true tails" containing the caudal vertebrae, a result of
atavism.
[
]
Humans have a "tail bone" (the
coccyx) attached to the pelvis; it comprises fused
vertebrae, usually four, at the bottom of the
vertebral column. It does not normally protrude externally - humans are an ''
acaudal'' (or ''acaudate'') species (i.e., tailless).
Gallery
File:Cub Stalks Tail.jpg, Lion (''Panthera leo'')
File:Scorpion tail.jpg, Scorpion
File:Pig tail DSC03974.jpg, Pig (''Sus domestica'')
File:Queue glyptodon museum dijo.jpg, Glyptodon (''Glyptodon asper'')
File:Lactoria cornuta (cola).006 - Aquarium Finisterrae.JPG, Longhorn cowfish (''Lactoria cornuta'')
File:La Palmyre 041-crop.jpg, Grévy's zebra (''Equus grevyi'')
File:Alligator Tail.jpg, American alligator (''Alligator mississipiensis'')
File:Flusspferd Backstage.JPG, Hippopotamus
The hippopotamus ( ; : hippopotamuses or hippopotami; ''Hippopotamus amphibius''), also called the hippo, common hippopotamus, or river hippopotamus, is a large semiaquatic mammal native to sub-Saharan Africa. It is one of only two exta ...
(''Hippopotamus amphibius'')
See also
*
Empennage
The empennage ( or ), also known as the tail or tail assembly, is a structure at the rear of an aircraft that provides stability during flight, in a way similar to the feathers on an arrow.Crane, Dale: ''Dictionary of Aeronautical Terms, third e ...
, the tail of an aircraft
*
Rump (animal)
References
External links
* {{Commons category-inline, Tails
Animal anatomy