Feeding is the process by which organisms, typically

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

s, obtain

food Food is any substance consumed by an organism for Nutrient, nutritional support. Food is usually of plant, animal, or Fungus, fungal origin and contains essential nutrients such as carbohydrates, fats, protein (nutrient), proteins, vitamins, ...

. Terminology often uses either the

suffix In linguistics, a suffix is an affix which is placed after the stem of a word. Common examples are case endings, which indicate the grammatical case of nouns and adjectives, and verb endings, which form the conjugation of verbs. Suffixes can ca ...

es -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 primarily eats fish. Fish were the diet of early tetrapod evolution (via water-bound amphibians during the Devonian period); insectivory came next; then in time, the more terrestrially adapted repti ...

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 the change in the heritable Phenotypic trait, characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, re ...

of form and function, such as: *

Mouth A mouth also referred to as the oral is the body orifice through which many animals ingest food and animal communication#Auditory, vocalize. The body cavity immediately behind the mouth opening, known as the oral cavity (or in Latin), is also t ...

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, tear ...

, such as in

whale Whales are a widely distributed and diverse group of fully Aquatic animal, aquatic placental mammal, placental marine mammals. As an informal and Colloquialism, colloquial grouping, they correspond to large members of the infraorder Cetacea ...

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

leech Leeches are segmented parasitism, parasitic or Predation, predatory worms that comprise the Class (biology), subclass Hirudinea within the phylum Annelida. They are closely related to the Oligochaeta, oligochaetes, which include the earthwor ...

es,

mosquito Mosquitoes, the Culicidae, are a Family (biology), family of small Diptera, flies consisting of 3,600 species. The word ''mosquito'' (formed by ''Musca (fly), mosca'' and diminutive ''-ito'') is Spanish and Portuguese for ''little fly''. Mos ...

s, predatory animals such as felines and

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

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 pecking, grasping, and holding (in probing for food, eating, manipulating and ...

s in

birds Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

, such as in

hawk Hawks are birds of prey of the family Accipitridae. They are very widely distributed and are found on all continents, except Antarctica. The subfamily Accipitrinae includes goshawks, sparrowhawks, sharp-shinned hawks, and others. This ...

woodpecker Woodpeckers are part of the bird family (biology), 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 ...

pelican Pelicans (genus ''Pelecanus'') are a genus of large water birds that make up the family Pelecanidae. They are characterized by a long beak and a large throat pouch used for catching prey and draining water from the scooped-up contents before ...

hummingbird Hummingbirds are birds native to the Americas and comprise the Family (biology), biological family Trochilidae. With approximately 366 species and 113 genus, genera, they occur from Alaska to Tierra del Fuego, but most species are found in Cen ...

parrot Parrots (Psittaciformes), also known as psittacines (), are birds with a strong curved beak, upright stance, and clawed feet. They are classified in four families that contain roughly 410 species in 101 genus (biology), genera, found mostly in ...

s, Kingfishers, 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 Arthro ...

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

primate Primates is an order (biology), order of mammals, which is further divided into the Strepsirrhini, strepsirrhines, which include lemurs, galagos, and Lorisidae, lorisids; and the Haplorhini, haplorhines, which include Tarsiiformes, tarsiers a ...

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 upper gastrointestinal tract of Human, humans and many other animals, including several invertebrates. The Ancient Greek name for the stomach is ''gaster'' which is used as ''gastric'' in medical t ...

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 Symbiosis (Ancient Greek : living with, companionship < : together; and ''bíōsis'': living) is any type of a close and long-term biological interaction, between two organisms of different species. The two organisms, termed symbionts, can fo ...

Classification

By mode of ingestion

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

Filter feeding Filter feeders are aquatic animals that acquire nutrients by feeding on organic matters, food particles or smaller organisms (bacteria, microalgae and zooplanktons) suspended in water, typically by having the water pass over or through a spe ...

: A form of food procurement in which food particles or small organisms are randomly strained from 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 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 pierce ...

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

Phagocytosis Phagocytosis () is the process by which a cell (biology), 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 ph ...

: 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 habit in an animal species, of eating and tolerating a relatively wide variety of foods, whereas monophagy is the intolerance of every food except for one specific type (see

generalist and specialist species A generalist species is able to thrive in a wide variety of environmental conditions and can make use of a variety of different resources (for example, a heterotroph with a varied diet). A specialist species can thrive only in a narrow range of en ...

Oligophagy Oligophagy refers to the eating of only a few specific foods, and to monophagy when restricted to a single food source. The term is usually associated with insect dietary behaviour.Johns, Timothy: The Origins of Human Diet and Medicine -- CHEMICAL ECOLOGY. ISBN 0-8165-1023-7, p. 5 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 Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they ar ...

: the eating of animals ** Araneophagy: eating spiders ** Avivore: eating birds ** Corallivore: eating coral ** Durophagy: eating hard-shelled or

exoskeleton An exoskeleton () . is a skeleton that is on the exterior of an animal in the form of hardened integument, which both supports the body's shape and protects the internal organs, in contrast to an internal endoskeleton (e.g. human skeleton, that ...

bearing organisms ** Egg predator: eating eggs (but also see " Intrauterine cannibalism" below), also Ovivore ** Haematophage/Sanguivore: eating blood **

Insectivore file:Common brown robberfly with prey.jpg, A Asilidae, robber fly eating a hoverfly An insectivore is a carnivore, carnivorous animal or plant which eats insects. An alternative term is entomophage, which can also refer to the Entomophagy ...

: eating insects *** Myrmecophage: eating ants and/or termites ** Invertivore: eating

invertebrates Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordate subphylum ...

** Keratophagy or Ceratophagy: eating

keratin Keratin () is one of a family of structural fibrous proteins also known as ''scleroproteins''. It is the key structural material making up Scale (anatomy), scales, hair, Nail (anatomy), nails, feathers, horn (anatomy), horns, claws, Hoof, hoove ...

-based material, such as wool by cloths moths, or snakes eating their own skin after

ecdysis Ecdysis is the moulting of the cuticle in many invertebrates of the clade Ecdysozoa. Since the cuticle of these animals typically forms a largely inelastic exoskeleton, it is shed during growth and a new, larger covering is formed. The remnant ...

. ** Lepidophagy: eating fish scales ** Molluscivore: eating molluscs ** Mucophagy: eating mucus ** Ophiophagy: eating snakes **

Piscivore A piscivore () is a carnivorous animal that primarily eats fish. Fish were the diet of early tetrapod evolution (via water-bound amphibians during the Devonian period); insectivory came next; then in time, the more terrestrially adapted repti ...

: eating fish ** Anurophagy: eating frogs ** Spongivore: eating sponges ** Teuthophagore: eating mainly squid and other cephalopods **

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

: eating worms ** Zooplanktonivore: eating zooplankton *

Herbivore A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat ...

: the eating of plants ** Exudativore: eating plant and/or insect exudates ( gum, sap, lerp, etc.) *** Gummivore: eating tree sap or gum ** Folivore: eating leaves ** Florivore: eating flower tissue prior to seed coat formation ** Frugivore: eating fruits ** Graminivore: eating grasses ** Granivore: eating seeds ** Nectarivore: eating nectar ** Palynivore: eating pollen ** Xylophage: eating wood * Algivore: eating

algae Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular ...

(both macroalgae and

microalgae Microalgae or microphytes are microscopic scale, microscopic algae invisible to the naked eye. They are phytoplankton typically found in freshwater and marine life, marine systems, living in both the water column and sediment. They are unicellul ...

) ** Phytoplanktonivore: eating

phytoplankton Phytoplankton () are the autotrophic (self-feeding) components of the plankton community and a key part of ocean and freshwater Aquatic ecosystem, ecosystems. The name comes from the Greek language, Greek words (), meaning 'plant', and (), mea ...

Omnivore An omnivore () is an animal that regularly consumes significant quantities of both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize t ...

: 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 that 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 exampl ...

: more than 70% meat **

Mesocarnivore A mesocarnivore is an animal whose diet consists of 30–70% 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 ...

: 30–70% meat ** Hypocarnivore: less than 30% meat * Fungivore: the eating of fungus * Bacterivore: the eating of bacteria The eating of non-living or decaying matter: * Coprophage: eating faeces *

Detritivore Detritivores (also known as detrivores, detritophages, detritus feeders or detritus eaters) are heterotrophs that obtain nutrients by consuming detritus (decomposing plant and animal parts as well as feces). There are many kinds of invertebrates, ...

: eating decomposing material *

Geophagia Geophagia (), also known as geophagy (), is the intentional practice of consuming 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 i ...

: eating inorganic earth * Osteophage: eating bones * Saprophage: eating decaying organic matter *

Scavenger Scavengers are animals that consume Corpse decomposition, dead organisms that have died from causes other than predation or have been killed by other predators. While scavenging generally refers to carnivores feeding on carrion, it is also a he ...

: eating carrion There are also several unusual feeding behaviours, either normal,

opportunistic 300px, ''Opportunity Seized, Opportunity Missed'', engraving by Theodoor Galle, 1605 Opportunism is the practice of taking advantage of circumstances — with little regard for principles or with what the consequences are for others. Opport ...

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

human Humans (''Homo sapiens'') or modern humans are the most common and widespread species of primate, and the last surviving species of the genus ''Homo''. They are Hominidae, great apes characterized by their Prehistory of nakedness and clothing ...

flesh ** Autocannibalism: feeding on parts of one's own body (see also

autophagy Autophagy (or autophagocytosis; from the Greek language, Greek , , meaning "self-devouring" and , , meaning "hollow") is the natural, conserved degradation of the cell that removes unnecessary or dysfunctional components through a lysosome-depe ...

) ** Filial cannibalism ** Intrauterine cannibalism *** Oophagy or ovophagy: the embryo/foetus eats sibling eggs *** Embryophagy: the foetus eats sibling embryos **

Sexual cannibalism Sexual cannibalism is when an animal, usually the female, Cannibalism, cannibalizes its mate prior to, during, or after Copulation (zoology), copulation. This trait is observed in many arachnid orders, several insect and crustacean clades, Gastro ...

: cannibalism after mating *

Kleptoparasitism Kleptoparasitism (originally spelt clepto-parasitism, meaning "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 f ...

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

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

: eating food regurgitated by another animal * Zoopharmacognosy:

self-medication Self-medication, sometime called do-it-yourself (DIY) medicine, 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 ...

by eating

plant Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they are predominantly Photosynthesis, photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with c ...

soil Soil, also commonly referred to as earth, is a mixture of organic matter, minerals, gases, water, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish dirt from ''soil'' by re ...

s, and

insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...

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 the act of engaging in excessive acquisition of items that are not needed or for which no space is available. Civil unrest or the threat of natural disasters may lead people to hoard foodstuffs, water, gasoline, and other essentials ...

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

References

Notes

{{Feeding * Ethology af:Voeding pt:Alimentação