Feeding is the process by which organisms, typically

animal Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motilit ...

s, obtain food. Terminology often uses either the suffixes -vore, -vory, or -vorous from Latin ''vorare'', meaning "to devour", or -phage, -phagy, or -phagous from Greek φαγεῖν (), meaning "to eat".

Evolutionary history

The evolution of feeding is varied with some feeding strategies evolving several times in independent lineages. In terrestrial vertebrates, the earliest forms were large amphibious

piscivore A piscivore () is a carnivorous animal that eats primarily fish. The name ''piscivore'' is derived . Piscivore is equivalent to the Greek-derived word ichthyophage, both of which mean "fish eater". Fish were the diet of early tetrapod evoluti ...

s 400 million years ago. While amphibians continued to feed on fish and later insects, reptiles began exploring two new food types, other tetrapods (carnivory), and later, plants (herbivory). Carnivory was a natural transition from insectivory for medium and large tetrapods, requiring minimal adaptation (in contrast, a complex set of adaptations was necessary for feeding on highly fibrous plant materials).

Evolutionary adaptations

The specialization of organisms towards specific food sources is one of the major causes of

evolution Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation ...

of form and function, such as: * mouth parts and

teeth A tooth ( : teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, t ...

, such as in

whale Whales are a widely distributed and diverse group of fully aquatic placental marine mammals. As an informal and colloquial grouping, they correspond to large members of the infraorder Cetacea, i.e. all cetaceans apart from dolphins and ...

vampire bat Vampire bats, species of the subfamily Desmodontinae, are leaf-nosed bats found in Central and South America. Their food source is blood of other animals, a dietary trait called hematophagy. Three extant bat species feed solely on blood: the ...

s, leeches,

mosquito Mosquitoes (or mosquitos) are members of a group of almost 3,600 species of small flies within the family Culicidae (from the Latin ''culex'' meaning " gnat"). The word "mosquito" (formed by ''mosca'' and diminutive ''-ito'') is Spanish for "li ...

s, predatory animals such as felines and

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of ...

es, etc. * distinct forms of

beak The beak, bill, or rostrum is an external anatomical structure found mostly in birds, but also in turtles, non-avian dinosaurs and a few mammals. A beak is used for eating, preening, manipulating objects, killing prey, fighting, probing for foo ...

s in birds, such as in hawks,

woodpecker Woodpeckers are part of the bird family Picidae, which also includes the piculets, wrynecks, and sapsuckers. Members of this family are found worldwide, except for Australia, New Guinea, New Zealand, Madagascar, and the extreme polar regions. ...

s, pelicans, hummingbirds,

parrot Parrots, also known as psittacines (), are birds of the roughly 398 species in 92 genera comprising the order Psittaciformes (), found mostly in tropical and subtropical regions. The order is subdivided into three superfamilies: the Psittacoide ...

kingfisher Kingfishers are a family, the Alcedinidae, of small to medium-sized, brightly colored birds in the order Coraciiformes. They have a cosmopolitan distribution, with most species found in the tropical regions of Africa, Asia, and Oceania, ...

s, etc. * specialized

claw A claw is a curved, pointed appendage found at the end of a toe or finger in most amniotes (mammals, reptiles, birds). Some invertebrates such as beetles and spiders have somewhat similar fine, hooked structures at the end of the leg or tarsus ...

s and other appendages, for apprehending or killing (including fingers in

primate Primates are a diverse order of mammals. They are divided into the strepsirrhines, which include the lemurs, galagos, and lorisids, and the haplorhines, which include the tarsiers and the simians ( monkeys and apes, the latter including ...

s) * changes in body colour for facilitating

camouflage Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard's spotted coat, the b ...

, disguise, setting up traps for preys, etc. * changes in the digestive system, such as the system of

stomach The stomach is a muscular, hollow organ in the gastrointestinal tract of humans and many other animals, including several invertebrates. The stomach has a dilated structure and functions as a vital organ in the digestive system. The stomach i ...

s of herbivores,

commensalism Commensalism is a long-term biological interaction ( symbiosis) in which members of one species gain benefits while those of the other species neither benefit nor are harmed. This is in contrast with mutualism, in which both organisms benefit fr ...

and symbiosis

Classification

By mode of ingestion

There are many modes of feeding that animals exhibit, including: *

Filter feeding Filter feeders are a sub-group of suspension feeding animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure. Some animals that use this method of feedin ...

: obtaining nutrients from particles suspended in water * Deposit feeding: obtaining nutrients from particles suspended in soil * Fluid feeding: obtaining nutrients by consuming other organisms' fluids *Bulk feeding: obtaining nutrients by eating all of an organism. *

Ram feeding Aquatic feeding mechanisms face a special difficulty as compared to feeding on land, because the density of water is about the same as that of the prey, so the prey tends to be pushed away when the mouth is closed. This problem was first identifi ...

and

suction feeding Aquatic feeding mechanisms face a special difficulty as compared to feeding on land, because the density of water is about the same as that of the prey, so the prey tends to be pushed away when the mouth is closed. This problem was first identifi ...

: ingesting prey via the fluids around it.

By mode of digestion

* Extra-cellular digestion: excreting digesting enzymes and then reabsorbing the products *

Myzocytosis Myzocytosis (from Greek: myzein, (') meaning "to suck" and kytos (') meaning "container", hence referring to "cell") is a method of feeding found in some heterotrophic organisms. It is also called "cellular vampirism" as the predatory cell pierces ...

: one cell pierces another using a feeding tube, and sucks out cytoplasm *

Phagocytosis Phagocytosis () is the process by which a cell uses its plasma membrane to engulf a large particle (≥ 0.5 μm), giving rise to an internal compartment called the phagosome. It is one type of endocytosis. A cell that performs phagocytosis is ...

: engulfing food matter into living cells, where it is digested

By food type

Polyphagy Feeding is the process by which organisms, typically animals, obtain food. Terminology often uses either the suffixes -vore, -vory, or -vorous from Latin ''vorare'', meaning "to devour", or -phage, -phagy, or -phagous from Greek φαγε ...

is the ability of an animal to eat a variety of food, whereas monophagy is the intolerance of every food except of one specific type (see generalist and specialist species). Another classification refers to the specific food animals specialize in eating, such as: *

Carnivore A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other s ...

: the eating of animals ** Araneophagy: eating spiders **

Avivore American kestrel eating bird. An avivore is a specialized predator of birds, with birds making up a large proportion of its diet. Such bird-eating animals come from a range of groups. Birds Birds that are specialized predators of other birds inc ...

: eating birds **

Corallivore A corallivore is an animal that feeds on coral. Corallivores are an important group of reef organism because they can influence coral abundance, distribution, and community structure. Corallivores feed on coral using a variety of unique adaptati ...

: eating coral **

Durophagy Durophagy is the eating behavior of animals that consume hard-shelled or exoskeleton bearing organisms, such as corals, shelled mollusks, or crabs. It is mostly used to describe fish, but is also used when describing reptiles, including fossil tu ...

: eating hard-shelled or

exoskeleton An exoskeleton (from Greek ''éxō'' "outer" and ''skeletós'' "skeleton") is an external skeleton that supports and protects an animal's body, in contrast to an internal skeleton (endoskeleton) in for example, a human. In usage, some of the ...

bearing organisms ** Egg predator: eating eggs (but also see "

Intrauterine cannibalism Cannibalism is the act of consuming another individual of the same species as food. Cannibalism is a common ecological interaction in the animal kingdom and has been recorded in more than 1,500 species. Human cannibalism is well documented, bo ...

" below), also Ovivore ** Haematophage/Sanguivore: eating blood ** Insectivore: eating insects *** Myrmecophage: eating ants and/or termites **

Invertivore Feeding is the process by which organisms, typically animals, obtain food. Terminology often uses either the suffixes -vore, -vory, or -vorous from Latin ''vorare'', meaning "to devour", or -phage, -phagy, or -phagous from Greek φαγ ...

: eating

invertebrates 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 chordat ...

** Keratophagy or

Ceratophagy This glossary of entomology describes terms used in the formal study of insect species by entomologists. A–C A synthetic chlorinated hydrocarbon insecticide, toxic to vertebrates. Though i ...

: eating horny material, such as wool by cloths moths, or snakes eating their own skin after ecdysis. **

Lepidophagy Lepidophagy is a specialised feeding behaviour in fish that involves eating the scales of other fish. Lepidophagy is widespread, having evolved independently in at least five freshwater families and seven marine families. A related feeding behav ...

: eating fish scales **

Molluscivore A molluscivore is a carnivorous animal that specialises in feeding on molluscs such as gastropods, bivalves, brachiopods and cephalopods. Known molluscivores include numerous predatory (and often cannibalistic) molluscs, (e.g.octopuses, murexes, d ...

: eating molluscs **

Mucophagy Mucophagy (literally "mucus feeding") is defined as the act of feeding on mucus of fishes or invertebrates. Also, it may refer to consumption of mucus or dried mucus in primates. There are mucophagous parasites, such as some types of sea lice tha ...

: eating mucus **

Ophiophagy Ophiophagy (Greek "snake eating") is a specialized form of feeding or alimentary behavior of animals which hunt and eat snakes. There are ophiophagous mammals (such as the skunks and the mongooses), birds (such as snake eagles, the secretarybird ...

: eating snakes **

Piscivore A piscivore () is a carnivorous animal that eats primarily fish. The name ''piscivore'' is derived . Piscivore is equivalent to the Greek-derived word ichthyophage, both of which mean "fish eater". Fish were the diet of early tetrapod evoluti ...

: eating fish ** Anurophagy: eating frogs **

Spongivore A spongivore is an animal anatomically and physiologically adapted to eating animals of the phylum Porifera, commonly called sea sponges, for the main component of its diet. As a result of their diet, spongivore animals like the hawksbill turtle ha ...

: eating sponges ** Teuthophagore: eating mainly squid and other cephalopods **

Vermivore Vermivore (from Latin vermi, meaning "worm" and vorare, "to devour") is a zoological term for animals that eat worms (including annelids, nematodes, and other worm-like animals). Animals with such a diet are known to be vermivorous. Some definiti ...

: eating worms ** Zooplanktonivore: eating zooplankton * Herbivore: the eating of plants ** Exudativore: eating plant and/or insect exudates (gum, sap, lerp, etc.) *** Gumivore: eating tree gum **

Folivore In zoology, a folivore is a herbivore that specializes in eating leaves. Mature leaves contain a high proportion of hard-to-digest cellulose, less energy than other types of foods, and often toxic compounds.Jones, S., Martin, R., & Pilbeam, D. (1 ...

: eating leaves **

Florivore In zoology, a florivore (not to be confused with a folivore) is an animal which mainly eats products of flowers. Florivores are types of herbivores (often referred to as floral herbivores), yet within the feeding behaviour of florivory, there are ...

: eating flower tissue prior to seed coat formation ** Frugivore: eating fruits **

Graminivore A graminivore is a herbivorous animal that feeds primarily on grass, specifically "true" grasses, plants of the family Poaceae (also known as Graminae). Graminivory is a form of grazing. These herbivorous animals have digestive systems that are a ...

: eating grasses **

Granivore Seed predation, often referred to as granivory, is a type of plant-animal interaction in which granivores (seed predators) feed on the seeds of plants as a main or exclusive food source,Hulme, P.E. and Benkman, C.W. (2002) "Granivory", pp. 13 ...

: eating seeds ** Nectarivore: eating nectar ** Palynivore: eating pollen ** Phytoplanktonivore: eating phytoplankton ** Xylophage: eating wood * Omnivore: the eating of both plants, animals, fungi, bacteria etc. The term means "all-eater". * By amount of meat in diet **

Hypercarnivore A hypercarnivore is an animal which has a diet that is more than 70% meat, either via active predation or by scavenging. The remaining non-meat diet may consist of non-animal foods such as fungi, fruits or other plant material. Some extant exam ...

: more than 70% meat **

Mesocarnivore A mesocarnivore is an animal whose diet consists of 50–70% meat with the balance consisting of non-vertebrate foods which may include insects, fungi, fruits, other plant material and any food that is available to them. Mesocarnivores are from a ...

: 30–70% meat **

Hypocarnivore A hypocarnivore is an animal that consumes less than 30% meat for its diet, the majority of which consists of fungi, fruits, and other plant material. Examples of living hypocarnivores are the grizzly bear (''Ursus horribilis''), American black be ...

: less than 30% meat *

Fungivore Fungivory or mycophagy is the process of organisms consuming fungi. Many different organisms have been recorded to gain their energy from consuming fungi, including birds, mammals, insects, plants, amoebas, gastropods, nematodes, bacteria and oth ...

: the eating of fungus *

Bacterivore A bacterivore is an organism which obtains energy and nutrients primarily or entirely from the consumption of bacteria. The term is most commonly used to describe free-living, heterotrophic, microscopic organisms such as nematodes as well as many s ...

: the eating of bacteria The eating of non-living or decaying matter: *

Coprophage Coprophagia () or coprophagy () is the consumption of feces. The word is derived from the grc, κόπρος , "feces" and , "to eat". Coprophagy refers to many kinds of feces-eating, including eating feces of other species (heterospecifics), of ...

: eating faeces * Detritivore: eating decomposing material *

Geophagia Geophagia (), also known as geophagy (), is the intentional practice of eating earth or soil-like substances such as clay, chalk, or termite mounds. It is a behavioural adaptation that occurs in many non-human animals and has been documented in ...

: eating inorganic earth * Osteophage: eating bones *

Saprophage Saprotrophic nutrition or lysotrophic nutrition is a process of chemoheterotrophic extracellular digestion involved in the processing of decayed (dead or waste) organic matter. It occurs in saprotrophs, and is most often associated with fungi ( ...

: eating decaying organic matter * Scavenger: eating carrion There are also several unusual feeding behaviours, either normal,

opportunistic Opportunism is the practice of taking advantage of circumstances – with little regard for principles or with what the consequences are for others. Opportunist actions are expedient actions guided primarily by self-interested motives. The term ...

, or pathological, such as: * Cannibalism: feeding on members of the same species **

Anthropophagy Anthropophagy is the custom and practice of eating human flesh. It may refer to: *Human cannibalism, when one human consumes the flesh of another ** Anthropophage, a member of a mythical race of cannibals **Child cannibalism, the act of eating a ...

: the practice of eating

human Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, cultu ...

flesh **

***

Oophagy Oophagy ( ) sometimes ovophagy, literally "egg eating", is the practice of embryos feeding on eggs produced by the ovary while still inside the mother's uterus. The word oophagy is formed from the classical Greek (, "egg") and classical Greek (, ...

or Ovophagy: the embryo/foetus eats sibling eggs *** Embryophagy: the foetus eats sibling embryos **

Filial cannibalism Filial cannibalism occurs when an adult individual of a species consumes all or part of the young of its own species or immediate offspring. Filial cannibalism occurs in many animal species ranging from mammals to insects, and is especially prevalen ...

Self-cannibalism Self-cannibalism is the practice of eating oneself, also called autocannibalism, or autosarcophagy. A similar term which is applied differently is '' autophagy'', which specifically denotes the normal process of self-degradation by cells. While alm ...

: feeding on parts of one's own body (see also autophagy) **

Sexual cannibalism Sexual cannibalism is when an animal, usually the female, cannibalizes its mate prior to, during, or after copulation.Polis, G.A. & Farley, R.D. Behavior and Ecology of Mating in the journal of Arachnology 33-46 (1979). It is a trait observed in ...

: cannibalism after mating *

Kleptoparasitism Kleptoparasitism (etymologically, parasitism by theft) is a form of feeding in which one animal deliberately takes food from another. The strategy is evolutionarily stable when stealing is less costly than direct feeding, which can mean when f ...

: stealing food from another animal * Kleptopharmacophagy: act of stealing chemical compounds for consumption *

Lignophagia Lignophagia is the List of abnormal behaviours in animals, abnormal behaviour of chewing and eating wood. It has been recorded in several species, but perhaps most commonly in horses where it is usually called, simply, "wood chewing". Lignophagia ...

: eating wood, typically a pathological condition in some domestic animals * Paedophagy: eating young animals * Pica: appetite for largely non-nutritive substances, e.g. clay or hair, sometimes in pregnancy or in pathological states, typically a medical or veterinary concern. *

Placentophagy Placentophagy, also known as placentophagia, is the act of consuming part or all of the afterbirth following parturition in mammals. Parturition involves the delivery of the neonate, as well as the placenta and fetal membranes. The placenta is ...

: eating placenta *

Trophallaxis Trophallaxis () is the transfer of food or other fluids among members of a community through mouth-to-mouth ( stomodeal) or anus-to-mouth ( proctodeal) feeding. Along with nutrients, trophallaxis can involve the transfer of molecules such as pher ...

: eating food regurgitated by another animal *

Zoopharmacognosy Zoopharmacognosy is a behaviour in which non-human animals self-medicate by selecting and ingesting or topically applying plants, soils, insects, and psychoactive drugs to prevent or reduce the harmful effects of pathogens, toxins, and even o ...

self-medication Self-medication is a human behavior in which an individual uses a substance or any exogenous influence to self-administer treatment for physical or psychological conditions: for example headaches or fatigue. The substances most widely used in sel ...

by eating

plant Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclu ...

soil Soil, also commonly referred to as earth or dirt Dirt is an unclean matter, especially when in contact with a person's clothes, skin, or possessions. In such cases, they are said to become dirty. Common types of dirt include: * Debri ...

s, and

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three ...

s to treat and prevent disease. An opportunistic feeder sustains itself from a number of different food sources, because the species is behaviourally sufficiently flexible.

Storage behaviours

Some animals exhibit

hoarding Hoarding is a behavior where people or animals accumulate food or other items. Animal behavior ''Hoarding'' and ''caching'' are common in many bird species as well as in rodents. Most animal caches are of food. However, some birds will a ...

and caching behaviours in which they store or hide food for later use.

References

Notes

{{Feeding * Ethology af:Voeding pt:Alimentação