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An omnivore () is an
animal Animals (also called Metazoa) are multicellular A multicellular organism is an organism In biology, an organism () is any organic, life, living system that functions as an individual entity. All organisms are composed of cells ...

animal
that has the ability to eat and survive on both plant and animal matter. Obtaining energy and
nutrient A nutrient is a substance Substance may refer to: * Substance (Jainism), a term in Jain ontology to denote the base or owner of attributes * Chemical substance, a material with a definite chemical composition * Matter, anything that has mass and t ...
s from plant and animal matter, omnivores digest
carbohydrate A carbohydrate () is a biomolecule , showing alpha helices, represented by ribbons. This poten was the first to have its suckture solved by X-ray crystallography by Max Perutz and Sir John Cowdery Kendrew in 1958, for which they received a ...
s,
protein Proteins are large biomolecule , showing alpha helices, represented by ribbons. This poten was the first to have its suckture solved by X-ray crystallography by Max Perutz and Sir John Cowdery Kendrew in 1958, for which they received a No ...

protein
,
fat In nutrition Nutrition is the biochemical Biochemistry or biological chemistry, is the study of chemical processes within and relating to living organisms. A sub-discipline of both chemistry and biology, biochemistry may be divided ...

fat
, and
fiber Fiber or fibre (from la, fibra, links=no) is a natural Nature, in the broadest sense, is the natural, physical, material world or universe The universe ( la, universus) is all of space and time and their contents, including ...
, and
metabolize Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life Life is a characteristic that distinguishes physical entities that have biological processes, such as Cell signaling, signaling and self-sustaining ...
the nutrients and energy of the sources absorbed. Often, they have the ability to incorporate food sources such as
algae Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic Photosynthesis is a process used by plants and other organisms to convert Conversion or convert may refer to: Arts, entertainment, and media * Co ...

algae
,
fungi A fungus (plural The plural (sometimes abbreviated An abbreviation (from Latin ''brevis'', meaning ''short'') is a shortened form of a word or phrase, by any method. It may consist of a group of letters, or words taken from the full ...

fungi
, and
bacteria Bacteria (; common noun bacteria, singular bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of prokaryotic microorganisms. Typ ...

bacteria
into their diet. Omnivores come from diverse backgrounds that often independently evolved sophisticated consumption capabilities. For instance, dogs evolved from primarily
carnivorous A carnivore , meaning "meat eater" (Latin, ''caro'', genitive ''carnis'', meaning "meat" or "flesh" and ''vorare'' meaning "to devour"), is an organism, animal whose food and energy requirements derive solely from animal Tissue (biology), tissu ...
organisms (
Carnivora Carnivora is an order of placental Placentalia is one of the three extant subdivisions of the class of animals Mammalia Mammals (from Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch ...
) while pigs evolved from primarily
herbivorous A herbivore is an animal Animals (also called Metazoa) are multicellular A multicellular organism is an organism In biology, an organism () is any organic, life, living system that functions as an individual entity. All ...
organisms (
Artiodactyla The even-toed ungulates (Artiodactyla , ) are ungulate Ungulates ( ) are members of the diverse Ungulata which primarily consists of large mammals with . These include s such as s, es, and s; and s such as , s, s, s, , , and es. s such as , ...
). Despite this, physical characteristics such as tooth morphology may be reliable indicators of diet in mammals, with such morphological adaptation having been observed in bears. The variety of different animals that are classified as omnivores can be placed into further sub-categories depending on their
feeding behaviors 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 ...
.
Frugivore A frugivore is an animal that thrives mostly on raw fruits or succulent fruit-like produce of plants such as roots, shoots, nuts and seeds. Approximately 20% of mammalian herbivores eat fruit. Frugivores are highly dependent on the abundance and ...
s include maned wolves and
orangutan Orangutans are great apes The Hominidae (), whose members are known as great apes or hominids (), are a taxonomic family In human society A society is a Social group, group of individuals involved in persistent Social relati ...

orangutan
s;
insectivore A robber fly eating a _.html" ;"title="hoverfly ">hoverfly File:Myresluger2.jpg">The giant anteater, a large insectivorous mammal An insectivore is a Carnivore, carnivorous plant or animal that eats insects. An alternative term is entomophage ...
s include
swallow The swallows, martins, and saw-wings, or Hirundinidae, are a family of passerine birds found around the world on all continents, including occasionally in Antarctica. Highly adapted to aerial feeding, they have a distinctive appearance. The term ...

swallow
s and
pink fairy armadillo The pink fairy armadillo (''Chlamyphorus truncatus'') or ''pichiciego'' is the smallest species of armadillo Armadillos (meaning "little armored ones" in Spanish) are New World placental mammals in the order (biology), order Cingulata. Th ...
s;
granivores Image:Aardbei muizenschade.jpg, A strawberry aggregate fruit, aggregate accessory fruit damaged by a mouse eating the seeds (achenes). Seed predation, often referred to as granivory, is a type of plant-animal interaction in which granivores (seed ...
include
large ground finches
large ground finches
and
mice A mouse, plural mice, is a small mammal Mammals (from Latin Latin (, or , ) is a classical language A classical language is a language A language is a structured system of communication Communication (from Latin ...

mice
. All of these animals are omnivores, yet still fall into special niches in terms of feeding behavior and preferred foods. Being omnivores gives these animals more
food security Food security is the measure of the availability of food and individuals' Economic inequality, ability to access it. According to the United Nations' Committee on World Food Security, food security is defined as meaning that all people, at all t ...
in stressful times or makes possible living in less consistent environments.


Etymology and definitions

The word ''omnivore'' derives from Latin ''omnis'' 'all' and ''vora'', from ''vorare'' 'to eat or devour', having been coined by the French and later adopted by the English in the 1800s. Traditionally the definition for omnivory was entirely behavioral by means of simply "including both animal and vegetable tissue in the diet." In more recent times, with the advent of advanced technological capabilities in fields like
gastroenterology Gastroenterology is the branch of medicine Medicine is the science Science () is a systematic enterprise that builds and organizes knowledge Knowledge is a familiarity, awareness, or understanding of someone or something, such as ...
, biologists have formulated a standardized variation of omnivore used for labeling a species' actual ability to obtain energy and nutrients from materials. This has subsequently conditioned two context specific definitions. * Behavioral: This definition is used to specify if a species or individual is actively consuming both plant and animal materials. ''(e.g. "
vegans Veganism is the practice of abstaining from the use of s, particularly in , and an associated philosophy that rejects the . An individual who follows the diet or philosophy is known as a vegan. Distinctions may be made between several catego ...
do not participate in the omnivore based diet.")'' In the fields of nutrition, sociology and psychology the term “omnivore” is often used to distinguish prototypical highly diverse human diet patterns from restricted diet patterns that exclude major categories of food. * Physiological: This definition is often used in academia to specify species that have the capability to obtain energy and nutrients from both plant and animal matter. ''(e.g. "humans are omnivores due to their capability to obtain energy and nutrients from both plant and animal materials.")'' The taxonomic utility of omnivore's traditional and behavioral definition is limited, since the diet, behavior, and
phylogeny A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram A diagram is a symbolic representation Representation may refer to: Law a ...

phylogeny
of one omnivorous species might be very different from that of another: for instance, an omnivorous pig digging for roots and scavenging for fruit and carrion is taxonomically and ecologically quite distinct from an omnivorous
chameleon Chameleons or chamaeleons (family In human society A society is a Social group, group of individuals involved in persistent Social relation, social interaction, or a large social group sharing the same spatial or social territory ...

chameleon
that eats leaves and insects. The term "omnivory" is also not always comprehensive because it does not deal with mineral foods such as salt licks and the consumption of plant and animal material for medical purposes which would not otherwise be consumed (i.e.
zoopharmacognosy Zoopharmacognosy is a behaviour in which non-human animals apparently self-medication, self-medicate by selecting and Ingestion, ingesting or Topical medication, topically applying plants, soils, insects, and psychoactive drugs to prevent or red ...
) within non-omnivores.


Classification, contradictions and difficulties

Though
Carnivora Carnivora is an order of placental Placentalia is one of the three extant subdivisions of the class of animals Mammalia Mammals (from Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch ...
is a
taxon In biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, chemical processes, Molecular biology, molecular interactions, Physiology, physiological mechani ...
for species classification, no such equivalent exists for omnivores, as omnivores are widespread across multiple taxonomic
clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyly, monophyletic – that is, composed of a common ancestor and all its lineage (evolution), lineal descendants - on a phylogenetic tree. R ...

clade
s. The Carnivora order does not include all carnivorous species, and not all species within the Carnivora taxon are carnivorous. (The members of Carnivora are formally referred as carnivorans.) It is common to find physiological carnivores consuming materials from plants or physiological herbivores consuming material from animals, e.g. felines eating grass and deer eating birds. From a behavioral aspect, this would make them omnivores, but from the physiological standpoint, this may be due to
zoopharmacognosy Zoopharmacognosy is a behaviour in which non-human animals apparently self-medication, self-medicate by selecting and Ingestion, ingesting or Topical medication, topically applying plants, soils, insects, and psychoactive drugs to prevent or red ...
. Physiologically, animals must be able to obtain both energy and nutrients from plant and animal materials to be considered omnivorous. Thus, such animals are still able to be classified as carnivores and herbivores when they are just obtaining nutrients from materials originating from sources that do not seemingly complement their classification. For instance, it is well documented that animals such as giraffes, camels, and cattle will gnaw on bones, preferably dry bones, for particular minerals and nutrients.
Felines The Felinae are a subfamily of the Family (biology), family Felidae. This subfamily comprises the small cats having a bony hyoid, because of which they are able to purr but not Roar (vocalization), roar. Other authors proposed an alternative def ...
, which are usually regarded as obligate carnivores, occasionally eat grass to regurgitate indigestibles (e.g. hair, bones), aid with hemoglobin production, and as a laxative. Occasionally, it is found that animals historically classified as carnivorous may deliberately eat plant material. For example, in 2013, it was considered that
American alligator The American alligator (''Alligator mississippiensis''), sometimes referred to colloquially as a gator or common alligator, is a large crocodilian Crocodilia (or Crocodylia, both ) is an order Order or ORDER or Orders may refer to: * O ...

American alligator
s (''Alligator mississippiensis'') may be physiologically omnivorous once investigations had been conducted on why they occasionally eat fruits. It was suggested that alligators probably ate fruits both accidentally and deliberately. "Life-history omnivores" is a specialized classification given to organisms that change their eating habits during their life cycle. Some species, such as grazing waterfowl like geese, are known to eat mainly animal tissue at one stage of their lives, but plant matter at another.Maclean, Gordon Lindsay (1993). ''Roberts' Birds of Southern Africa''. Publisher: New Holland. . The same is true for many insects, such as beetles in the
family In human society A society is a Social group, group of individuals involved in persistent Social relation, social interaction, or a large social group sharing the same spatial or social territory, typically subject to the same Politic ...
Meloidae, which begin by eating animal tissue as
larva A larva (plural larvae ) is a distinct juvenile form many animal Animals (also called Metazoa) are multicellular A multicellular organism is an organism In biology, an organism () is any organic, life, living system that f ...
e, but change to eating plant matter after they mature. Likewise, many
mosquito Mosquitoes are members of a group of almost 3,600 species In biology, a species is the basic unit of biological classification, classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defin ...

mosquito
species in early life eat plants or assorted detritus, but as they mature, males continue to eat plant matter and nectar whereas the females (such as those of ''
Anopheles ''Anopheles'' () is a genus Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank In biological classification In biology Biology is the natural science that studies life and living organisms, including th ...
'', ''
Aedes ''Aedes'' is a genus Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank In biological classification In biology Biology is the natural science that studies life and living organisms, including their an ...
'' and ''
Culex ''Culex'' is a genus Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank In biological classification In biology Biology is the natural science that studies life and living organisms, including their ...
'') also eat blood to reproduce effectively.


Omnivorous species


General

Although cases exist of
herbivore A herbivore is an animal Animals (also called Metazoa) are multicellular A multicellular organism is an organism In biology, an organism () is any organic, life, living system that functions as an individual entity. All ...
s eating meat and
carnivore A carnivore , meaning "meat Meat is animal Animals (also called Metazoa) are multicellular eukaryotic organisms that form the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume orga ...
s eating
plant Plants are predominantly photosynthetic Photosynthesis is a process used by plants and other organisms to Energy transformation, convert light energy into chemical energy that, through cellular respiration, can later be released to fuel ...

plant
matter, the classification "omnivore" refers to the adaptation and main food source of the species in general, so these exceptions do not make either individual animals or the species as a whole omnivorous. For the concept of "omnivore" to be regarded as a
scientific classification In biology, taxonomy () is the scientific study of naming, defining (Circumscription (taxonomy), circumscribing) and classifying groups of biological organisms based on shared characteristics. Organisms are grouped into taxon, taxa (singular: ...

scientific classification
, some clear set of measurable and relevant criteria would need to be considered to differentiate between an "omnivore" and other categories, e.g. faunivore,
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. (199 ...
, and
scavenger Scavengers are animals that consume dead organisms that have died from causes other than predation Predation is a biological interaction In ecology Ecology (from el, οἶκος, "house" and el, -λογία, label=none, "study ...
. Some researchers argue that evolution of any species from herbivory to carnivory or carnivory to herbivory would be rare except via an intermediate stage of omnivory.


Omnivorous mammals

Various
mammal Mammals (from Latin Latin (, or , ) is a classical language A classical language is a language A language is a structured system of communication Communication (from Latin ''communicare'', meaning "to share" or "to be i ...
s are omnivorous in the wild, such as species of
hominids The Hominidae (), whose members are known as great apes or hominids (), are a taxonomic Family (biology), family of primates that includes eight Neontology#Extant taxa versus extinct taxa, extant species in four Genus, genera: ''Orangutan, Pon ...
,
pig The pig (''Sus domesticus''), often called swine, hog, or domestic pig when distinguishing from other members of the genus '' Sus'', is an omnivorous An omnivore () is an animal that has the ability to eat and survive on both plant and ani ...

pig
s,
badger Badgers are short-legged omnivore An omnivore () is an animal Animals (also called Metazoa) are multicellular eukaryotic organisms that form the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotro ...

badger
s,
bear Bears are carnivora Carnivora is an order of placental Placentalia is one of the three extant subdivisions of the class of animals Mammalia Mammals (from Latin Latin (, or , ) is a classical language belonging to the Ita ...

bear
s,
coati Coatis, also known as coatimundis (), are members of the family Procyonidae Procyonidae is a New World family (biology), family of the order (biology), order Carnivora. It comprises the Procyon (genus), raccoons, Ring-tailed cat, ringtails ...

coati
s,
civet A civet () is a small, lean, mostly nocturnal Nocturnality is an animal behavior Ethology is the scientific Science (from the Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch ...

civet
s,
hedgehog A hedgehog is a spiny mammal of the subfamily Erinaceinae, in the eulipotyphlan family (biology), family Erinaceidae. There are seventeen species of hedgehog in five genus, genera found throughout parts of Europe, Asia, and Africa, and in Ne ...

hedgehog
s,
opossum Opossums () are members of the marsupial Order (biology), order Didelphimorphia () Endemism, endemic to the Americas. The largest order of marsupials in the Western Hemisphere, it comprises 120+ species in 19 Genus, genera. Opossums originated i ...

opossum
s,
skunk Skunks are mammals Mammals (from Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken in the area around Rome, known as Latium. T ...

skunk
s,
sloth Sloths are a group of arboreal Neotropical xenarthran mammals, constituting the suborder Folivora. Noted for their slowness of movement, they spend most of their lives hanging upside down in the trees of the tropical rainforest File:Kop ...

sloth
s,
squirrel Squirrels are members of the family In human society A society is a Social group, group of individuals involved in persistent Social relation, social interaction, or a large social group sharing the same spatial or social terri ...

squirrel
s,
raccoon The raccoon ( or , ''Procyon lotor''), sometimes called the common raccoon to distinguish it from other species, is a medium-sized mammal Mammals (from Latin Latin (, or , ) is a classical language belonging to the Italic bra ...

raccoon
s,
chipmunk Chipmunks are small, striped rodents of the family Sciuridae. Chipmunks are found in North America, with the exception of the Siberian chipmunk which is found primarily in Asia. Taxonomy and systematics Chipmunks may be classified either as a ...

chipmunk
s,
mice A mouse, plural mice, is a small mammal Mammals (from Latin Latin (, or , ) is a classical language A classical language is a language A language is a structured system of communication Communication (from Latin ...

mice
, and
rat Rats are various medium-sized, long-tailed rodent Rodents (from Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken in the area a ...

rat
s. Most bear species are omnivores, but individual diets can range from almost exclusively herbivorous ( hypocarnivore) to almost exclusively carnivorous (
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 exampl ...
), depending on what food sources are available locally and seasonally.
Polar bear The polar bear (''Ursus Ursus is Latin for bear. It may also refer to: Animals *Ursus (mammal), ''Ursus'' (mammal), a genus of bears People * Ursus of Aosta, 6th-century evangelist * Ursus of Auxerre, 6th-century bishop * Ursus of Soloth ...

Polar bear
s are classified as carnivores, both taxonomically (they are in the
order Order, ORDER or Orders may refer to: * Orderliness Orderliness is a quality that is characterized by a person’s interest in keeping their surroundings and themselves well organized, and is associated with other qualities such as cleanliness a ...
Carnivora), and behaviorally (they subsist on a largely carnivorous diet). Depending on the species of bear, there is generally a preference for one class of food, as plants and animals are digested differently. Canines including
wolves The wolf (''Canis lupus''), also known as the gray wolf or grey wolf, is a large canine native to Eurasia Eurasia () is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern Hemisphere, N ...

wolves
,
dog The dog or domestic dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated Domestication is a sustained multi-generational relationship in which one group of organisms assumes a significant degree of influence over the ...

dog
s,
dingo The dingo (''Canis familiaris'', ''Canis familiaris dingo'', ''Canis dingo'', or ''Canis lupus dingo'') is an ancient (Basal (phylogenetics), basal) lineage of dog found in Australia (continent), Australia. Its taxonomic classification is deba ...

dingo
es, and
coyote The coyote (''Canis latrans'') is a species of canis, canine native to North America. It is smaller than its close relative, the wolf, and slightly smaller than the closely related eastern wolf and red wolf. It fills much of the same ecologica ...

coyote
s eat some plant matter, but they have a general preference and are evolutionarily geared towards meat. However, the
maned wolf The maned wolf (''Chrysocyon brachyurus'') is a large canine Canine may refer to: Zoology * dog-like mammals (i.e. members of the canid subfamily Caninae) ** ''Canis'', a genus including dogs, wolves, coyotes, and jackals ** Dog, the domestic do ...
is a canid whose diet is naturally 50% plant matter. Like most arboreal species, squirrels are primarily granivores, subsisting on nuts and seeds. However, like virtually all mammals, squirrels avidly consume some animal food when it becomes available. For example, the American
eastern gray squirrel The eastern gray squirrel (''Sciurus carolinensis''), also known as simply the grey squirrel, is a tree squirrel in the genus ''Sciurus''. It is native to eastern North America, where it is the most prodigious and ecologically essential natural ...

eastern gray squirrel
has been introduced to parts of Britain, continental Europe and South Africa. Its effect on populations of nesting birds is often serious because of consumption of eggs and nestlings.


Other species

Various
bird Birds are a group of warm-blooded vertebrate Vertebrates () comprise all species of animal Animals (also called Metazoa) are multicellular eukaryotic organisms that form the Kingdom (biology), biological kingdom Animalia. With ...

bird
s are omnivorous, with diets varying from
berries A berry is a small, pulpy, and often edible fruit. Typically, berries are juicy, rounded, brightly colored, sweet, sour or tart, and do not have a stone or pit, although many pips or seeds may be present. Common examples are strawberries, raspb ...

berries
and
nectar Nectar is a sugar Sugar is the generic name for , soluble s, many of which are used in food. Simple sugars, also called s, include , , and . Compound sugars, also called s or double sugars, are molecules made of two monosaccharides jo ...

nectar
to
insect Insects (from Latin Latin (, or , ) is a classical language A classical language is a language A language is a structured system of communication Communication (from Latin ''communicare'', meaning "to share" or "to be in ...

insect
s,
worm Worms are many different distantly related bilateral animals that typically have a long cylindrical tube-like body, no limb Limb can refer to: *Limb (anatomy), an appendage of a human or animal *Limb Music, a record label *Limb (album), an ...

worm
s,
fish Fish are aquatic Aquatic means relating to water Water (chemical formula H2O) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the ...

fish
, and small
rodent Rodents (from Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally spoken in the area around Rome, known as Latium. Through the power of the Roman Republi ...

rodent
s. Examples include cranes,
cassowaries ''Casuarius'' is a genus of birds in the order Casuariiformes, whose members are the cassowaries. It is classified as a ratite (flightless bird without a keel (bird anatomy), keel on its sternum bone) and is native to the tropical forests of Ne ...

cassowaries
,
chicken The chicken (''Gallus gallus domesticus'') is a domestication, domesticated subspecies of the red junglefowl originally from Southeastern Asia. Rooster or cock is a term for an adult male bird, and a younger male may be called a cockerel. A m ...

chicken
s,
crow A crow is a bird of the genus ''Corvus ''Corvus'' is a widely distributed genus Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms ...

crow
s and related
corvids Corvidae is a cosmopolitan Cosmopolitan may refer to: Food and drink * Cosmopolitan (cocktail), also known as a "Cosmo" History * Rootless cosmopolitan, a Soviet derogatory epithet during Joseph Stalin's anti-Semitic campaign of 1949–1953 ...

corvids
,
kea The kea (; ; ''Nestor notabilis'') is a species of large parrot in the Family (biology), family Nestoridae found in the forested and alpine regions of the South Island of New Zealand. About long, it is mostly olive-green with a brilliant orang ...

kea
,
rallidae The rails, or Rallidae, are a large cosmopolitan Cosmopolitan may refer to: Food and drink * Cosmopolitan (cocktail), also known as a "Cosmo" History * Rootless cosmopolitan, a Soviet derogatory epithet during Joseph Stalin's anti-Semitic ca ...
, and
rheas The rheas () are large ratite A ratite () is any of a diverse group of mostly flightless s are a well-known example of flightless birds. Flightless birds are birds that through evolution lost the ability to flight, fly. There are over 60 ...
. In addition, some
lizard Lizards (suborder In biological classification, the order ( la, wikt:ordo#Latin, ordo) is # a taxonomic rank used in the classification of organisms and recognized by the nomenclature codes. The well-known ranks in descending order are: lif ...

lizard
s (such as Galapagos Lava Lizard ,
turtle Turtles are an order Order, ORDER or Orders may refer to: * Orderliness Orderliness is a quality that is characterized by a person’s interest in keeping their surroundings and themselves well organized, and is associated with other qu ...

turtle
s, fish (such as
piranha A piranha or piraña (, , or ; , ), a member of family In human society, family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpo ...

piranha
s and
catfish Catfish (or catfishes; order Order or ORDER or Orders may refer to: * Orderliness Orderliness is associated with other qualities such as cleanliness Cleanliness is both the abstract state of being clean and free from germs, dirt, trash, o ...

catfish
), and
invertebrate Invertebrates are animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This includes all animals apart from the chordata, chordate subphylum vertebrate, Vertebra ...
s are omnivorous. Quite often, mainly herbivorous creatures will eagerly eat small quantities of animal food when it becomes available. Although this is trivial most of the time, omnivorous or herbivorous birds, such as sparrows, often will feed their chicks insects while food is most needed for growth. On close inspection it appears that nectar-feeding birds such as sunbirds rely on the ants and other insects that they find in flowers, not for a richer supply of protein, but for essential nutrients such as
cobalt Cobalt is a chemical element In chemistry, an element is a pure Chemical substance, substance consisting only of atoms that all have the same numbers of protons in their atomic nucleus, nuclei. Unlike chemical compounds, chemical element ...

cobalt
/
vitamin b12 Vitamin B12, also known as cobalamin, is a water-soluble vitamin A vitamin is an organic molecule , CH4; is among the simplest organic compounds. In chemistry, organic compounds are generally any chemical compounds that contain carbo ...

vitamin b12
that are absent from nectar. Similarly, monkeys of many species eat maggoty fruit, sometimes in clear preference to sound fruit.Ewing, Jack (2005). ''Monkeys Are Made of Chocolate''. Publisher: Pixyjack Press. . When to refer to such animals as omnivorous, or otherwise, is a question of context and emphasis, rather than of definition.


See also


References

{{Authority control Animals by eating behaviors Ethology