Omnivore

Last updated

Examples of omnivores. From left to right: humans, dogs, pigs, channel catfish, American crows, gravel ant Omnivore Examples.png
Examples of omnivores. From left to right: humans, dogs, pigs, channel catfish, American crows, gravel ant
Among birds, the hooded crow is a typical omnivore. Kraka (Corvus corone) - Ystad-2023.jpg
Among birds, the hooded crow is a typical omnivore.

An omnivore ( /ˈɒmnɪvɔːr/ ) is an animal that has the ability to eat and survive on both plant and animal matter. [3] Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nutrients and energy of the sources absorbed. [4] Often, they have the ability to incorporate food sources such as algae, fungi, and bacteria into their diet. [5] [6] [7]

Contents

Omnivores come from diverse backgrounds that often independently evolved sophisticated consumption capabilities. For instance, dogs evolved from primarily carnivorous organisms (Carnivora) while pigs evolved from primarily herbivorous organisms (Artiodactyla). [8] [9] [10] 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. [11] [12]

The variety of different animals that are classified as omnivores can be placed into further sub-categories depending on their feeding behaviors. Frugivores include cassowaries, orangutans and grey parrots; [13] [14] [15] insectivores include swallows and pink fairy armadillos; [16] [17] granivores include large ground finches and 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 in stressful times or makes possible living in less consistent environments. [18]

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. [19] Traditionally the definition for omnivory was entirely behavioral by means of simply "including both animal and vegetable tissue in the diet. [20] " In more recent times, with the advent of advanced technological capabilities in fields like gastroenterology, biologists have formulated a standardized variation of omnivore used for labeling a species' actual ability to obtain energy and nutrients from materials. [21] [22] This has subsequently conditioned two context-specific definitions.

The taxonomic utility of omnivore's traditional and behavioral definition is limited, since the diet, behavior, and phylogeny of one omnivorous species may 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 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 or with non-omnivores that self-medicate by consuming either plant or animal material which they otherwise would not (i.e. zoopharmacognosy).

Classification, contradictions and difficulties

Though Carnivora is a taxon for species classification, no such equivalent exists for omnivores, as omnivores are widespread across multiple taxonomic clades. 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 to as carnivorans.) [33] 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. [34] [35] From a behavioral aspect, this would make them omnivores, but from the physiological standpoint, this may be due to zoopharmacognosy. 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. [36] Felines, 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. [37]

Occasionally, it is found that animals historically classified as carnivorous may deliberately eat plant material. For example, in 2013, it was considered that American alligators (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. [38]

"Life-history omnivores" is a specialized classification given to organisms that change their eating habits during their life cycle. [39] 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. [40] The same is true for many insects, such as beetles in the family Meloidae, [41] which begin by eating animal tissue as larvae, but change to eating plant matter after they mature. Likewise, many 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 , Aedes and Culex ) also eat blood to reproduce effectively. [42]

Omnivorous species

General

Although cases exist of herbivores eating meat and carnivores eating 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, 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, and scavenger. [43] 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. [44]

Omnivorous mammals

Various mammals are omnivorous in the wild, such as species of hominids, pigs, [45] badgers, bears, foxes, coatis, civets, hedgehogs, opossums, skunks, sloths, squirrels, [46] raccoons, chipmunks, [47] mice, [48] hamsters and rats. [49] [7] [50] [51]

Most bear species are omnivores Brown bears salmon.jpg
Most bear species are omnivores

Most bear species are omnivores, [52] but individual diets can range from almost exclusively herbivorous (hypocarnivore) to almost exclusively carnivorous (hypercarnivore), depending on what food sources are available locally and seasonally. Polar bears are classified as carnivores, both taxonomically (they are in the order 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, dogs, dingoes, and coyotes eat some plant matter, but they have a general preference and are evolutionarily geared towards meat. [53] However, the maned wolf is a canid whose diet is naturally 50% plant matter.

Like most arboreal species, squirrels are primarily granivores, subsisting on nuts and seeds. [54] However, like virtually all mammals, squirrels avidly consume some animal food when it becomes available. For example, the American 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. [55] [56]

Other species

Various birds are omnivorous, with diets varying from berries and nectar to insects, worms, fish, and small rodents. Examples include cranes, cassowaries, chickens, crows [57] and related corvids, kea, rallidae, and rheas. In addition, some lizards (such as Galapagos Lava Lizard), turtles, fish (such as piranhas and catfish), and invertebrates 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. [58] 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/vitamin b12 that are absent from nectar. Similarly, monkeys of many species eat maggoty fruit, sometimes in clear preference to sound fruit. [59] When to refer to such animals as omnivorous, or otherwise, is a question of context and emphasis, rather than of definition.

See also

Related Research Articles

<span class="mw-page-title-main">Carnivore</span> Organism that eats mostly or exclusively animal tissue

A carnivore, or meat-eater, is an animal or plant whose food and energy requirements derive from the consumption of animal tissues whether through hunting or scavenging.

<span class="mw-page-title-main">Food</span> Substances consumed for nutrition

Food is any substance consumed by an organism for nutritional support. Food is usually of plant, animal, or fungal origin and contains essential nutrients such as carbohydrates, fats, proteins, vitamins, or minerals. The substance is ingested by an organism and assimilated by the organism's cells to provide energy, maintain life, or stimulate growth. Different species of animals have different feeding behaviours that satisfy the needs of their metabolisms and have evolved to fill a specific ecological niche within specific geographical contexts.

<span class="mw-page-title-main">Nutrition</span> Provision to cells and organisms to support life

Nutrition is the biochemical and physiological process by which an organism uses food to support its life. It provides organisms with nutrients, which can be metabolized to create energy and chemical structures. Failure to obtain the required amount of nutrients causes malnutrition. Nutritional science is the study of nutrition, though it typically emphasizes human nutrition.

<span class="mw-page-title-main">Ringtail</span> Species of mammal

The ringtail is a mammal of the raccoon family native to arid regions of North America. It is widely distributed and well adapted to disturbed areas. It has been legally trapped for its fur. It is listed as Least Concern on the IUCN Red List. The species is known by variety of different names, such as ring-tailed cat, miner's cat, civet cat, and cacomistle, though the last of these can refer to B. sumichrasti.

<span class="mw-page-title-main">Eating</span> Ingestion of food

Eating is the ingestion of food. In biology, this is typically done to provide a heterotrophic organism with energy and nutrients and to allow for growth. Animals and other heterotrophs must eat in order to survive — carnivores eat other animals, herbivores eat plants, omnivores consume a mixture of both plant and animal matter, and detritivores eat detritus. Fungi digest organic matter outside their bodies as opposed to animals that digest their food inside their bodies.

<span class="mw-page-title-main">Insectivore</span> Organism which eats insects

An insectivore is a carnivorous animal or plant that eats insects. An alternative term is entomophage, which can also refer to the human practice of eating insects.

<span class="mw-page-title-main">Diet (nutrition)</span> Sum of food consumed by an organism

In nutrition, diet is the sum of food consumed by a person or other organism. The word diet often implies the use of specific intake of nutrition for health or weight-management reasons. Although humans are omnivores, each culture and each person holds some food preferences or some food taboos. This may be due to personal tastes or ethical reasons. Individual dietary choices may be more or less healthy.

<span class="mw-page-title-main">Caniformia</span> Suborder of mammals

Caniformia is a suborder within the order Carnivora consisting of "dog-like" carnivorans. They include dogs, bears, raccoons, and mustelids. The Pinnipedia are also assigned to this group. The center of diversification for the Caniformia is North America and northern Eurasia. Caniformia stands in contrast to the other suborder of Carnivora, the Feliformia, the center of diversification of which was in Africa and southern Asia.

<span class="mw-page-title-main">Folivore</span> Herbivorous animal that specializes in eating leaves

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. For this reason, folivorous animals tend to have long digestive tracts and slow metabolisms. Many enlist the help of symbiotic bacteria to release the nutrients in their diet. Additionally, as has been observed in folivorous primates, they exhibit a strong preference for immature leaves which tend to be easier to masticate, are higher in energy and protein, and lower in fibre and poisons than more mature fibrous leaves.

<span class="mw-page-title-main">Red-bellied piranha</span> Fish species native to South America

The red-bellied piranha, also known as the red piranha, is a type of piranha native to South America, found in the Amazon, Paraguay, Paraná and Essequibo basins, as well as coastal rivers of northeastern Brazil. This fish is locally abundant in its freshwater habitat. They are omnivorous foragers and feed on insects, worms, crustaceans, and fish. They are not a migratory species but do travel to seek out conditions conducive to breeding and spawning during periods of increased rainfall. Red-bellied piranhas often travel in shoals as a predatory defense but rarely exhibit group hunting behavior. Acoustic communication is common and is sometimes exhibited along with aggressive behaviors. They are a popular aquarium fish.

<span class="mw-page-title-main">Protocarnivorous plant</span> Carnivorous plant that can not digest prey

A protocarnivorous plant, according to some definitions, traps and kills insects or other animals but lacks the ability to either directly digest or absorb nutrients from its prey like a carnivorous plant. The morphological adaptations such as sticky trichomes or pitfall traps of protocarnivorous plants parallel the trap structures of confirmed carnivorous plants.

The wildlife of Iraq includes its flora and fauna and their natural habitats. Iraq has multiple biomes from mountainous region in the north to the wet marshlands along the Euphrates river. The western part of the country is mainly desert and some semi-arid regions. As of 2001, seven of Iraq's mammal species and 12 of its bird species were endangered. The endangered species include the northern bald ibis and Persian fallow deer. The Syrian wild ass is extinct, and the Saudi Arabian dorcas gazelle was declared extinct in 2008.

<span class="mw-page-title-main">Feliformia</span> Suborder of carnivores

Feliformia is a suborder within the order Carnivora consisting of "cat-like" carnivorans, including cats, hyenas, mongooses, viverrids, and related taxa. Feliformia stands in contrast to the other suborder of Carnivora, Caniformia.

<span class="mw-page-title-main">Trophic level</span> Position of an organism in a food chain

The trophic level of an organism is the position it occupies in a food web. A food chain is a succession of organisms that eat other organisms and may, in turn, be eaten themselves. The trophic level of an organism is the number of steps it is from the start of the chain. A food web starts at trophic level 1 with primary producers such as plants, can move to herbivores at level 2, carnivores at level 3 or higher, and typically finish with apex predators at level 4 or 5. The path along the chain can form either a one-way flow or a food "web". Ecological communities with higher biodiversity form more complex trophic paths.

<span class="mw-page-title-main">Carnivorous plant</span> Plants that consume animals

Carnivorous plants are plants that derive some or most of their nutrients from trapping and consuming animals or protozoans, typically insects and other arthropods, and occasionally small mammals and birds. They still generate all of their energy from photosynthesis. They have adapted to grow in waterlogged sunny places where the soil is thin or poor in nutrients, especially nitrogen, such as acidic bogs. They can be found on all continents except Antarctica, as well as many Pacific islands. In 1875, Charles Darwin published Insectivorous Plants, the first treatise to recognize the significance of carnivory in plants, describing years of painstaking research.

<span class="mw-page-title-main">Mesocarnivore</span> Organism that eats mostly animal tissue

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 large family group of mammalian carnivores and vary from small to medium sized, which are less than fifteen kilograms. Mesocarnivores are seen today among the Canidae, Viverridae (civets), Mustelidae, Procyonidae, Mephitidae (skunks), and Herpestidae. The red fox is also the most common of the mesocarnivores in Europe and has a high population density in the areas they reside.

A consumer in a food chain is a living creature that eats organisms from a different population. A consumer is a heterotroph and a producer is an autotroph. Like sea angels, they take in organic moles by consuming other organisms, so they are commonly called consumers. Heterotrophs can be classified by what they usually eat as herbivores, carnivores, omnivores, or decomposers. On the other hand, autotrophs are organisms that use energy directly from the sun or from chemical bonds. Autotrophs are vital to all ecosystems because all organisms need organic molecules, and only autotrophs can produce them from inorganic compounds. Autotrophs are classified as either photoautotrophs or chemoautotrophs.

Consumer–resource interactions are the core motif of ecological food chains or food webs, and are an umbrella term for a variety of more specialized types of biological species interactions including prey-predator, host-parasite, plant-herbivore and victim-exploiter systems. These kinds of interactions have been studied and modeled by population ecologists for nearly a century. Species at the bottom of the food chain, such as algae and other autotrophs, consume non-biological resources, such as minerals and nutrients of various kinds, and they derive their energy from light (photons) or chemical sources. Species higher up in the food chain survive by consuming other species and can be classified by what they eat and how they obtain or find their food.

Lepidosaur herbivory describes herbivorous lepidosaurs. Living non-avian reptiles form a paraphyletic group that consists of over 9,000 species of crocodiles, turtles, and lepidosaurs. The most diverse group, Lepidosauria, is first known from the Middle Triassic fossils, but likely originated in the Permian. Living lepidosaurs, which include snakes, lizards, and rhynchocephalians, occupy a wide range of environments and niches. The lepidosaurs have many similar anatomical morphology like transverse cloaca, distal tongue, superficial teeth attachment, fused pelvic bones etc. Though widely viewed as obligate carnivores, a small number of lepidosaurs are known to consume plant material. For example, there are roughly 3,300 species of living lizards and approximately 3% of them eat at least some plants. Though the exact definition of herbivory varies significantly between scientists, most define herbivorous lepidosaurs as those that consume plants for approximately 70-90% of its diet.

References

  1. ↑ Beasley, DeAnna; Koltz, Amanda; Lambert, Joanna; Fierer, Noah; Dunn, Rob (29 July 2015). "The Evolution of Stomach Acidity and Its Relevance to the Human Microbiome". PLOS ONE. 10 (7): e0134116. Bibcode:2015PLoSO..1034116B. doi: 10.1371/journal.pone.0134116 . PMC   4519257 . PMID   26222383.
  2. ↑ Dewey, T. & Bhagat, S. (2002). "Canis lupus familiaris". Animal Diversity Web. Retrieved 3 April 2016.
  3. ↑ Brooker RJ (2008). Biology . McGraw-Hill. p. 1326. ISBN   978-0072956207.
  4. ↑ Pond G, Ullrey DE, Baer CK (2018). Encyclopedia of Animal Science - (Two-Volume Set). McGraw-Hill. p. 1350. ISBN   978-0072956207.
  5. ↑ Bradford, Alina (25 January 2016). "Reference: Omnivores: Facts About Flexible Eaters". Livescience. Retrieved 2 April 2016.
  6. 1 2 "Omnivore". National Geographic Education. National Geographic Society. 21 January 2011. Archived from the original on 9 January 2013. Retrieved 4 October 2012.
  7. 1 2 McArdle, John. "Humans are Omnivores". Vegetarian Resource Group. Retrieved 6 October 2013.
  8. ↑ "Why Your Dog's Pedigree Goes Back 40 Million Years". About.com Education. Retrieved 2 April 2016.
  9. ↑ "Evolutionary History of Pigs – Domesticating Wilbur". blogs.lt.vt.edu. Retrieved 2 April 2016.
  10. ↑ "Order Cetartiodactyla - Even-toed ungulates (and whales)". www.ultimateungulate.com. Retrieved 2 April 2016.
  11. ↑ Evans, Alistair R.; Pineda-Munoz, Silvia (2018), Croft, Darin A.; Su, Denise F.; Simpson, Scott W. (eds.), "Inferring Mammal Dietary Ecology from Dental Morphology", Methods in Paleoecology: Reconstructing Cenozoic Terrestrial Environments and Ecological Communities, Vertebrate Paleobiology and Paleoanthropology, Springer International Publishing, pp. 37–51, doi:10.1007/978-3-319-94265-0_4, ISBN   978-3-319-94265-0
  12. ↑ Sacco, Tyson; Valkenburgh, Blaire Van (2004). "Ecomorphological indicators of feeding behaviour in the bears (Carnivora: Ursidae)". Journal of Zoology. 263 (1): 41–54. doi:10.1017/S0952836904004856. ISSN   1469-7998.
  13. ↑ "Diet and metabolism", Parrots of Africa, Madagascar and the Mascarene Islands, Wits University Press, pp. 159–191, 2012, doi:10.18772/22012125522.13, ISBN   9781868145911 , retrieved 5 June 2023
  14. ↑ "Cassowary". San Diego Zoo Wildlife Alliance. 2022. Retrieved 18 September 2022.
  15. ↑ Galdikas, Biruté M. F. (1 February 1988). "Orangutan diet, range, and activity at Tanjung Puting, Central Borneo". International Journal of Primatology. 9 (1): 1–35. doi:10.1007/BF02740195. ISSN   0164-0291. S2CID   40513842.
  16. ↑ McCarty, John P.; Winkler, David W. (1 January 1999). "Foraging Ecology and Diet Selectivity of Tree Swallows Feeding Nestlings". The Condor. 101 (2): 246–254. doi: 10.2307/1369987 . JSTOR   1369987.
  17. ↑ Superina, Mariella (1 March 2011). "Husbandry of a pink fairy armadillo (Chlamyphorus truncatus): case study of a cryptic and little known species in captivity". Zoo Biology. 30 (2): 225–231. doi:10.1002/zoo.20334. hdl: 11336/80345 . ISSN   1098-2361. PMID   20648566.
  18. ↑ Shute, Nancy (20 April 2012). "For Most Of Human History, Being An Omnivore Was No Dilemma". NPR. Retrieved 3 April 2016.
  19. ↑ "omnivore: definition of omnivore (American English) (US)". Oxford dictionary. Archived from the original on 16 March 2013. Retrieved 2 April 2016.
  20. ↑ Collocott, T. C., ed. (1974). Chambers Dictionary of science and technology. Edinburgh: W. and R. Chambers. ISBN   978-0-550-13202-4.
  21. 1 2 "Omnivore - Biology-Online Dictionary". www.biology-online.org. Retrieved 2 April 2016.
  22. 1 2 "omnivore - definition of omnivore in English from the Oxford dictionary". www.oxforddictionaries.com. Archived from the original on 5 October 2014. Retrieved 2 April 2016.
  23. ↑ "Definition of OMNIVORE". www.merriam-webster.com. Retrieved 2 April 2016.
  24. ↑ "omnivore Definition in the Cambridge English Dictionary". dictionary.cambridge.org. Retrieved 2 April 2016.
  25. ↑ Clarys, Peter; Deliens, Tom; Huybrechts, Inge; Deriemaeker, Peter; Vanaelst, Barbara; De Keyzer, Willem; Hebbelinck, Marcel; Mullie, Patrick (24 March 2014). "Comparison of Nutritional Quality of the Vegan, Vegetarian, Semi-Vegetarian, Pesco-Vegetarian and Omnivorous Diet". Nutrients. 6 (3): 1318–1332. doi: 10.3390/nu6031318 . ISSN   2072-6643. PMC   3967195 . PMID   24667136.
  26. ↑ Michel, Fabienne; Knaapila, Antti; Hartmann, Christina; Siegrist, Michael (1 July 2021). "A multi-national comparison of meat eaters' attitudes and expectations for burgers containing beef, pea or algae protein". Food Quality and Preference. 91: 104195. doi: 10.1016/j.foodqual.2021.104195 . hdl: 20.500.11850/471981 . ISSN   0950-3293.
  27. ↑ Valente, Martina; Syurina, Elena V.; Muftugil-Yalcin, Seda; Cesuroglu, Tomris (1 November 2020). ""Keep Yourself Alive": From Healthy Eating to Progression to Orthorexia Nervosa A Mixed Methods Study among Young Women in the Netherlands". Ecology of Food and Nutrition. 59 (6): 578–597. Bibcode:2020EcoFN..59..578V. doi: 10.1080/03670244.2020.1755279 . ISSN   0367-0244. PMID   32366121.
  28. ↑ Norris, Catherine J.; Do, Elena; Close, Emma; Deswert, Sky (1 September 2019). "Ambivalence toward healthy and unhealthy food and moderation by individual differences in restrained eating". Appetite. 140: 309–317. doi:10.1016/j.appet.2019.05.033. ISSN   0195-6663. PMID   31136805. S2CID   164216932.
  29. ↑ Schreiner, Philipp; Yilmaz, Bahtiyar; Rossel, Jean-Benoît; Franc, Yannick; Misselwitz, Benjamin; Scharl, Michael; Zeitz, Jonas; Frei, Pascal; Greuter, Thomas; Vavricka, Stephan R.; Pittet, Valérie (July 2019). "Vegetarian or gluten-free diets in patients with inflammatory bowel disease are associated with lower psychological well-being and a different gut microbiota, but no beneficial effects on the course of the disease". United European Gastroenterology Journal. 7 (6): 767–781. doi:10.1177/2050640619841249. ISSN   2050-6406. PMC   6620875 . PMID   31316781.
  30. ↑ O'Malley, Keelia; Willits-Smith, Amelia; Aranda, Rodrigo; Heller, Martin; Rose, Diego (1 June 2019). "Vegan vs Paleo: Carbon Footprints and Diet Quality of 5 Popular Eating Patterns as Reported by US Consumers (P03-007-19)". Current Developments in Nutrition. 3 (Supplement_1): nzz047.P03–007–19. doi: 10.1093/cdn/nzz047.P03-007-19 . PMC   6574879 .
  31. ↑ Reece, Jane (10 November 2013). Campbell Biology (10th ed.). Boston: Pearson. pp. Chapter 55. ISBN   978-0321775658.
  32. ↑ "Animals: Carnivore, Herbivore or Omnivore?". science made simple. 27 February 2014. Retrieved 2 April 2016.
  33. ↑ Ewer, R. F. (1973). The Carnivores. London: Weidenfeld and Nicolson. ISBN   978-0-297-99564-7.
  34. ↑ "Why Dogs Eat Grass ~ Dr. Richard Orzeck". www.worldsvet.com. Retrieved 17 April 2016.
  35. ↑ "White-tailed deer shown to raid nests, eat eggs and baby birds, USGS reports". NOLA.com. Retrieved 17 April 2016.
  36. ↑ Hutson, Jarod M.; Burke, Chrissina C.; Haynes, Gary (1 December 2013). "Osteophagia and bone modifications by giraffe and other large ungulates". Journal of Archaeological Science. 40 (12): 4139–4149. Bibcode:2013JArSc..40.4139H. doi:10.1016/j.jas.2013.06.004.
  37. ↑ Negron, Vladimir (20 April 2009). "Why do cats eat grass?". petMD.
  38. ↑ Platt, S. G.; Elsey, R. M.; Liu, H.; Rainwater, T. R.; Nifong, J. C.; Rosenblatt, A. E.; Heithaus, M. R.; Mazzotti, F. J. (2013). "Frugivory and seed dispersal by crocodilians: an overlooked form of saurochory?". Journal of Zoology. 291 (2): 87–99. doi: 10.1111/jzo.12052 . ISSN   1469-7998.
  39. ↑ "Omnivore". www.eoearth.org. Retrieved 3 April 2016.
  40. ↑ Maclean, Gordon Lindsay (1993). Roberts' Birds of Southern Africa. Publisher: New Holland. ISBN   978-0620175838.
  41. ↑ Skaife, S. H. (1953). African Insect Life. Pub. Longmans, Green & Co., London.
  42. ↑ "Anopheles Male Vs. Female". animals.mom.me. Retrieved 17 April 2016.
  43. ↑ Singer, Michael S.; Bernays, Elizabeth A. (2003). "Understanding Omnivory Needs: A Behavioral Perspective". Ecology . 84 (10): 2532–2537. Bibcode:2003Ecol...84.2532S. doi:10.1890/02-0397.
  44. ↑ "Omnivores' ancestors primarily ate plants, or animals, but not both". 17 April 2012. Retrieved 17 April 2012.
  45. ↑ Brent Huffman. "Family Suidae (Pigs)". UltimateUngulate.com. Archived from the original on 7 January 2019. Retrieved 29 December 2007.
  46. ↑ "Tree Squirrels". The Humane Society of the United States. Archived from the original on 25 December 2008. Retrieved 1 January 2009.
  47. ↑ "Eastern Chipmunk". Wonder Club. Retrieved 1 January 2009.
  48. ↑ "Florida Mouse". United States Fauna. Archived from the original on 29 August 2007. Retrieved 1 January 2009.
  49. ↑ "Brown Rat". Science Daily. Archived from the original on 31 December 2008. Retrieved 1 January 2009.
  50. ↑ Robert E. C. Wildman; Denis M. Medeiros (2000). Advanced Human Nutrition. CRC Press. p. 37. ISBN   978-0849385667 . Retrieved 6 October 2013.
  51. ↑ Robert Mari Womack (2010). The Anthropology of Health and Healing. Rowman & Littlefield. p. 243. ISBN   978-0759110441 . Retrieved 6 October 2013.
  52. ↑ "Food and Diet". bearsmart.com. Retrieved 3 July 2013.
  53. ↑ "About Wolves". Wolf Park. Archived from the original on 20 November 2015. Retrieved 26 August 2015.
  54. ↑ Halle, S. & Stenseth, N. (2000). Activity patterns in small mammals: an ecological approach. Berlin; Heidelberg, Germany; New York: Springer-Verlag. p. 131.
  55. ↑ Annex: Towards a Forestry Commission England Grey Squirrel Policy (PDF), UK: Forestry Commission, 22 January 2006, archived from the original (PDF) on 7 April 2017, retrieved 15 May 2012
  56. ↑ Moller, H. (1983). "Food and foraging behaviour of red (Scirus vulgaris) and grey (Scirus carolinensis) squirrels". Mammal Review13: 81-98.
  57. ↑ Seattle Audubon Society. "Family Corvidae (Crows/Ravens)". BirdWeb.org. Retrieved 1 January 2011.
  58. ↑ Capinera, John (2010). Insects and Wildlife. Publisher: Wiley-Blackwell. ISBN   978-1-4443-3300-8.
  59. ↑ Ewing, Jack (2005). Monkeys Are Made of Chocolate. Publisher: Pixyjack Press. ISBN   978-0-9658098-1-8.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.