73-596: A wood buffalo is another name for a wood bison . Wood buffalo may also refer to: Wood bison The wood bison ( Bison bison athabascae ) or mountain bison (often called the wood buffalo or mountain buffalo ), is a distinct northern subspecies or ecotype of the American bison . Its original range included much of the boreal forest regions of Alaska , Yukon , western Northwest Territories , northeastern British Columbia , northern Alberta , and northwestern Saskatchewan . The term "buffalo"
146-427: A barrier between the bison and their food source, so they must use their large heads and neck muscles to dig for edible morsels. After the temperature rises and the snow melts, wood bison also feed on silverberry and willow leaves in the summer. Researchers believe wood bison are beneficiaries of a natural law known as Bergmann's rule due to their sheer size. Their increased body mass over their southern cousin,
219-481: A byproduct of metabolizing the food, further contributing to maintaining body temperature. Although wood bison are native to Canada and Alaska, they have also been introduced to Yakutia , Russia as part of an ongoing species restoration project. Yakutia provides similar climatic conditions as in Canada, albeit with colder average temperatures. The Northwest Territories in Canada can drop as low as −60 °C during
292-523: A decrease in abundance of leaf-chewing larvae in the fall when hardwood leaf palatability decreases due to increased tannin levels which results in a decline of arthropod species richness , and increased palatability of plant communities at higher elevations where grasshoppers abundances are lower. Climatic stressors such as ocean acidification can lead to responses in plant-herbivore interactions in relation to palatability as well. The myriad defenses displayed by plants means that their herbivores need
365-623: A greater and more diverse set of resources. Coevolution and phylogenetic correlation between herbivores and plants are important aspects of the influence of herbivore and plant interactions on communities and ecosystem functioning, especially in regard to herbivorous insects. This is apparent in the adaptations plants develop to tolerate and/or defend from insect herbivory and the responses of herbivores to overcome these adaptations. The evolution of antagonistic and mutualistic plant-herbivore interactions are not mutually exclusive and may co-occur. Plant phylogeny has been found to facilitate
438-465: A herbivore in a dense forest would spend more time handling (eating) the vegetation because there was so much vegetation around than a herbivore in a sparse forest, who could easily browse through the forest vegetation. According to the Holling's disk equation, a herbivore in the sparse forest would be more efficient at eating than the herbivore in the dense forest. The marginal value theorem describes
511-495: A mutual relationship with the plant species that they forage by digging and disturbing the sediment which removes competing plants and subsequently allows colonization of other plant species. When herbivores are affected by trophic cascades , plant communities can be indirectly affected. Often these effects are felt when predator populations decline and herbivore populations are no longer limited, which leads to intense herbivore foraging which can suppress plant communities. With
584-557: A new patch of food when the patch they are currently feeding on requires more energy to obtain food than an average patch. Within this theory, two subsequent parameters emerge, the Giving Up Density (GUD) and the Giving Up Time (GUT). The Giving Up Density (GUD) quantifies the amount of food that remains in a patch when a forager moves to a new patch. The Giving Up Time (GUT) is used when an animal continuously assesses
657-774: A remote area to form the second herd. Pleistocene Park in Yakutia originally wanted to bring wood bison into its enclosures, but failed to do so and brought in European bison instead. 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 non-vascular autotrophs such as mosses , algae and lichens , but do not include those feeding on decomposed plant matters (i.e. detritivores ) or macrofungi (i.e. fungivores ). As
730-715: A result of their plant-based diet, herbivorous animals typically have mouth structures ( jaws or mouthparts ) well adapted to mechanically break down plant materials, and their digestive systems have special enzymes (e.g. amylase and cellulase ) to digest polysaccharides . Grazing herbivores such as horses and cattles have wide flat- crowned teeth that are better adapted for grinding grass , tree bark and other tougher lignin -containing materials, and many of them evolved rumination or cecotropic behaviors to better extract nutrients from plants. A large percentage of herbivores also have mutualistic gut flora made up of bacteria and protozoans that help to degrade
803-520: A similar meaning. Though the name "bison" might be considered to be more scientifically correct, the name "buffalo" is listed in many dictionaries as an acceptable alternative for American bison. In reference to this animal, the term "buffalo" dates to 1635 in North American usage when the term was first recorded for the American mammal. It thus has a longer history than the term "bison", which
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#1732802063707876-635: A single plant can have hundreds of different chemical defenses. Chemical defenses can be divided into two main groups, carbon-based defenses and nitrogen-based defenses. Plants have also changed features that enhance the probability of attracting natural enemies to herbivores. Some emit semiochemicals, odors that attract natural enemies, while others provide food and housing to maintain the natural enemies' presence, e.g. ants that reduce herbivory. A given plant species often has many types of defensive mechanisms, mechanical or chemical, constitutive or induced, which allow it to escape from herbivores. According to
949-574: A terrestrial mammal to be called a grazer, at least 90% of the forage has to be grass, and for a browser at least 90% tree leaves and twigs. An intermediate feeding strategy is called "mixed-feeding". In their daily need to take up energy from forage, herbivores of different body mass may be selective in choosing their food. "Selective" means that herbivores may choose their forage source depending on, e.g., season or food availability, but also that they may choose high quality (and consequently highly nutritious) forage before lower quality. The latter especially
1022-399: A tradeoff however, between foraging on many plant species to avoid toxins or specializing on one type of plant that can be detoxified. Herbivore modification is when various adaptations to body or digestive systems of the herbivore allow them to overcome plant defenses. This might include detoxifying secondary metabolites , sequestering toxins unaltered, or avoiding toxins, such as through
1095-438: A trophic cascade involved plant-herbivore interactions are coral reef ecosystems. Herbivorous fish and marine animals are important algae and seaweed grazers, and in the absence of plant-eating fish, corals are outcompeted and seaweeds deprive corals of sunlight. Agricultural crop damage by the same species totals approximately $ 100 million every year. Insect crop damages also contribute largely to annual crop losses in
1168-579: A variety of physical and metabolic alterations in the way the host plant interacts with itself and other surrounding biotic factors. Fungi, bacteria, and protists that feed on living plants are usually termed plant pathogens (plant diseases), while fungi and microbes that feed on dead plants are described as saprotrophs . Flowering plants that obtain nutrition from other living plants are usually termed parasitic plants . There is, however, no single exclusive and definitive ecological classification of consumption patterns; each textbook has its own variations on
1241-527: A variety of skills to overcome these defenses and obtain food. These allow herbivores to increase their feeding and use of a host plant. Herbivores have three primary strategies for dealing with plant defenses: choice, herbivore modification, and plant modification. Feeding choice involves which plants a herbivore chooses to consume. It has been suggested that many herbivores feed on a variety of plants to balance their nutrient uptake and to avoid consuming too much of any one type of defensive chemical. This involves
1314-460: Is a model for predicting animal behavior while looking for food or other resources, such as shelter or water. This model assesses both individual movement, such as animal behavior while looking for food, and distribution within a habitat, such as dynamics at the population and community level. For example, the model would be used to look at the browsing behavior of a deer while looking for food, as well as that deer's specific location and movement within
1387-742: Is a possibility that there are surviving pure wood bison. Publicly owned free-ranging herds in Alberta, British Columbia, Yukon, and the Northwest Territories comprise 90% of existing wood bison, although six smaller public and private captive-breeding herds with conservation objectives comprise roughly 10% of the total, or around 900 head. These captive herds and two large isolated free-ranging herds all derive from disease-free and morphologically representative founding stock from Wood Buffalo National Park. These captive herds are particularly important for conservation and recovery purposes, because
1460-403: Is aided in reproduction. Plants can also be indirectly affected by herbivores through nutrient recycling , with plants benefiting from herbivores when nutrients are recycled very efficiently. Another form of plant-herbivore mutualism is physical changes to the environment and/or plant community structure by herbivores which serve as ecosystem engineers , such as wallowing by bison. Swans form
1533-506: Is considered to be a misnomer for this animal, as it is only distantly related to either of the two "true buffalo", the water buffalo and the African buffalo . However, " bison " is a Greek word meaning an ox -like animal, while "buffalo" originated with the French fur trappers who called these massive beasts bœufs , meaning ox or bullock—so both names, "bison" and "buffalo", have
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#17328020637071606-431: Is derived from Latin herba 'small plant, herb' and vora , from vorare 'to eat, devour'. Herbivory is a form of consumption in which an organism principally eats autotrophs such as plants , algae and photosynthesizing bacteria . More generally, organisms that feed on autotrophs in general are known as primary consumers . Herbivory is usually limited to animals that eat plants. Insect herbivory can cause
1679-563: Is determined by the body mass of the herbivore, with small herbivores selecting for high-quality forage, and with increasing body mass animals are less selective. Several theories attempt to explain and quantify the relationship between animals and their food, such as Kleiber's law , Holling's disk equation and the marginal value theorem (see below). Kleiber's law describes the relationship between an animal's size and its feeding strategy, saying that larger animals need to eat less food per unit weight than smaller animals. Kleiber's law states that
1752-783: Is irrelevant and derived to explain trends that do not exist in nature. Holling's disk equation models the efficiency at which predators consume prey. The model predicts that as the number of prey increases, the amount of time predators spend handling prey also increases, and therefore the efficiency of the predator decreases. In 1959, S. Holling proposed an equation to model the rate of return for an optimal diet: Rate (R )=Energy gained in foraging (Ef)/(time searching (Ts) + time handling (Th)) R = E f / ( T s + T h ) {\displaystyle R=Ef/(Ts+Th)} Where s=cost of search per unit time f=rate of encounter with items, h=handling time, e=energy gained per encounter. In effect, this would indicate that
1825-488: Is the ability of a plant to withstand damage without a reduction in fitness. This can occur by diverting herbivory to non-essential plant parts, resource allocation, compensatory growth, or by rapid regrowth and recovery from herbivory. Resistance refers to the ability of a plant to reduce the amount of damage it receives from herbivores. This can occur via avoidance in space or time, physical defenses, or chemical defenses. Defenses can either be constitutive, always present in
1898-464: Is unclear whether today's animals preserve the original phenotypes existing prior to the 1920s. The wood bison is larger and heavier than the plains bison. Despite a limited number of samples, large males have been recorded to reach 3.35 m (11.0 ft) in body length with 95 cm (3.12 ft) tails, 201 cm (6.59 ft) tall at withers , and 1,179 kg (2,600 lb) in weight, making it morphologically more similar to at least one of
1971-417: The cattle industry rapidly encroaching on the park's boundaries. Disease management strategies and initiatives began in the 1950s and have yet to result in a reduction of the incidence of either disease, despite considerable expenditure and increased public involvement. The herd currently has a total population around 2,500, largely as a result of conservation efforts by Canadian government agencies. In 1988,
2044-491: The cellulose in plants, whose heavily cross-linking polymer structure makes it far more difficult to digest than the protein - and fat -rich animal tissues that carnivores eat. Herbivore is the anglicized form of a modern Latin coinage, herbivora , cited in Charles Lyell 's 1830 Principles of Geology . Richard Owen employed the anglicized term in an 1854 work on fossil teeth and skeletons. Herbivora
2117-403: The plains bison , produces more heat and provides a larger frame on which to store fat for the winter months. This, along with several other adaptations, helps the animal survive in the harsh climate of northern Canada and Alaska . The wooly hair that covers the body is such an effective insulator that falling snow will collect on the bison rather than melting, further insulating the animal from
2190-432: The wetland ecosystem . Such differences in herbivore modalities can potentially lead to trade-offs that influence species traits and may lead to additive effects on community composition and ecosystem functioning. Seasonal changes and environmental gradients such as elevation and latitude often affect the palatability of plants which in turn influences herbivore community assemblages and vice versa. Examples include
2263-630: The 1920s, being measured from degrees of morphological overlaps between pure plains bison, even surpassing the preserved herds at Elk Island National Park and Mackenzie Bison Sanctuary. Natural hybridization between wood and plains bison presumably occurred for a limited extent in the regions where the two ecotypes (or subspecies) overlapped. Wood–plains hybrids are generally called "Parkland bison". As below-mentioned, disease-free and genetically unique populations of wood bison have been discovered in recent years. If these populations had little or no contacts with bison from Wood Buffalo National Park, there
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2336-686: The Committee on the Status of Endangered Wildlife in Canada changed the subspecies' conservation status from "endangered" to " threatened ", where it remains. On June 17, 2008, 53 wood bison were transferred from Alberta's Elk Island National Park to the Alaska Wildlife Conservation Center in Anchorage, Alaska . There they were to be held in quarantine for two years and then reintroduced to their native habitat in
2409-671: The Minto Flats area near Fairbanks , but this plan was placed on hold. In May 2014, the U.S. Fish and Wildlife Service published a final rule allowing the reintroduction of a "non-essential experimental" population of wood bison into three areas of Alaska. As a result, the Alaska Department of Fish and Game introduced the first herd of 100 animals to the Innoko River area in western Alaska in spring 2015. Currently, about 7,000 wood bison remain in wildernesses within
2482-568: The Northwest Territories, the Yukon, British Columbia, Alberta, and Manitoba . Recently, several bison herds that are disease-free, and genetically unique compared to the populations within Wood Buffalo National Park (WBNP), have been detected. These herds were once considered as merely split groups from WBNP bison, however members of First Nations and Métis community members claimed that they knew for generations that one of
2555-515: The U.S. Herbivores also affect economics through the revenue generated by hunting and ecotourism. For example, the hunting of herbivorous game species such as white-tailed deer, cottontail rabbits, antelope, and elk in the U.S. contributes greatly to the billion-dollar annually, hunting industry. Ecotourism is a major source of revenue, particularly in Africa, where many large mammalian herbivores such as elephants, zebras, and giraffes help to bring in
2628-416: The balance between eating all the food in a patch for immediate energy, or moving to a new patch and leaving the plants in the first patch to regenerate for future use. The theory predicts that absent complicating factors, an animal should leave a resource patch when the rate of payoff (amount of food) falls below the average rate of payoff for the entire area. According to this theory, an animal should move to
2701-704: The chronological subspecies of ancestral steppe bisons ( Bison priscus sp.) and Bison occidentalis . It is among the largest extant bovids and is the heaviest and longest terrestrial animal in North America and Siberia. The peak of the wood bison's shoulder hump sits anterior to the forelegs, while the plains bison's shoulder hump is located directly above the forelegs. Wood bison also have larger horn cores, darker and woollier hair and less hair on their forelegs, with smaller and more pointed beards. Plains bison are capable of running faster, reaching up to 65 km/h (40 mph), and longer than bison living in
2774-412: The cold. When food becomes more scarce in the winter, wood bison are also capable of slowing down their metabolic rate. The primary benefit is slower digestion rates which means the animals are able to pull more nutrients out of each meal. This results in fewer necessary feedings to maintain energy demands. In addition to greater nutrient absorption, the slower digestion rate means more heat is produced as
2847-824: The colonization and community assembly of herbivores, and there is evidence of phylogenetic linkage between plant beta diversity and phylogenetic beta diversity of insect clades such as butterflies . These types of eco-evolutionary feedbacks between plants and herbivores are likely the main driving force behind plant and herbivore diversity. Abiotic factors such as climate and biogeographical features also impact plant-herbivore communities and interactions. For example, in temperate freshwater wetlands herbivorous waterfowl communities change according to season, with species that eat above-ground vegetation being abundant during summer, and species that forage below-ground being present in winter months. These seasonal herbivore communities differ in both their assemblage and functions within
2920-424: The effectiveness of plant defenses activated by sunlight. A plant defense is a trait that increases plant fitness when faced with herbivory. This is measured relative to another plant that lacks the defensive trait. Plant defenses increase survival and/or reproduction (fitness) of plants under pressure of predation from herbivores. Defense can be divided into two main categories, tolerance and resistance. Tolerance
2993-538: The end of that period. Herbivory among four-limbed terrestrial vertebrates, the tetrapods , developed in the Late Carboniferous (307–299 million years ago). The oldest known example being Desmatodon hesperis. Early tetrapods were large amphibious piscivores . While amphibians continued to feed on fish and insects, some reptiles began exploring two new food types, tetrapods (carnivory) and plants (herbivory). The entire dinosaur order ornithischia
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3066-532: The extremely small sizes of other herds, and the herd became protected under a unique designation. To strengthen the protections, a new sanctuary Kitaskino Nuwenëné Wildland Provincial Park was established in 2019 by a historic collaboration of the government and indigenous communities including first nations. Along with the Ronald Lake herd, the much smaller Wabasca herd has also become a subject of special protection. The reintroductions of muskoxen and
3139-493: The first land plants evolved. Insects fed on the spores of early Devonian plants, and the Rhynie chert also provides evidence that organisms fed on plants using a "pierce and suck" technique. During the next 75 million years , plants evolved a range of more complex organs, such as roots and seeds. There is no evidence of any organism being fed upon until the middle-late Mississippian , 330.9 million years ago . There
3212-596: The food chain because they consume plants to digest the carbohydrates photosynthetically produced by a plant. Carnivores in turn consume herbivores for the same reason, while omnivores can obtain their nutrients from either plants or animals. Due to a herbivore's ability to survive solely on tough and fibrous plant matter, they are termed the primary consumers in the food cycle (chain). Herbivory, carnivory, and omnivory can be regarded as special cases of consumer–resource interactions . Two herbivore feeding strategies are grazing (e.g. cows) and browsing (e.g. moose). For
3285-565: The food source, in this case, the plant. Several factors play into these fluctuating populations and help stabilize predator-prey dynamics. For example, spatial heterogeneity is maintained, which means there will always be pockets of plants not found by herbivores. This stabilizing dynamic plays an especially important role for specialist herbivores that feed on one species of plant and prevents these specialists from wiping out their food source. Prey defenses also help stabilize predator-prey dynamics, and for more information on these relationships see
3358-426: The forested habitat and its interaction with other deer while in that habitat. This model has been criticized as circular and untestable. Critics have pointed out that its proponents use examples that fit the theory, but do not use the model when it does not fit the reality. Other critics point out that animals do not have the ability to assess and maximize their potential gains, therefore the optimal foraging theory
3431-472: The forests and mountains. Wood bison reach sexual maturity at age 2. Females will often rear their first calf by age 3 and may produce a single additional offspring every 1–2 years. Mating season typically runs from July to September, with most activity occurring during August as evidenced by the fact most calves are born in May following a 9-month gestation period. Bison young are precocial , with many mastering
3504-832: The fossil record of their jaws near the Permio-Carboniferous boundary, approximately 300 million years ago. The earliest evidence of their herbivory has been attributed to dental occlusion , the process in which teeth from the upper jaw come in contact with teeth in the lower jaw is present. The evolution of dental occlusion led to a drastic increase in plant food processing and provides evidence about feeding strategies based on tooth wear patterns. Examination of phylogenetic frameworks of tooth and jaw morphologes has revealed that dental occlusion developed independently in several lineages tetrapod herbivores. This suggests that evolution and spread occurred simultaneously within various lineages. Herbivores form an important link in
3577-552: The genetic stock , the phenotype, and health condition. Between 1925 and 1928, 6,673 plains bisons, compared to 1,500–2,000 wood bisons, were translocated from Buffalo National Park into the Wood Buffalo National Park by the Government of Canada, to avoid mass culling because of overpopulation, despite protests from conservation biologists. The translocation was regarded as a severe tragedy because all
3650-407: The herds, the Ronald Lake herd, is a separated population. This, and genetic uniqueness and disease-free conditions of these herds indicate that these herds either remained isolated or had limited contacts with animals from WBNP despite being located adjacent to the boundary of WBNP. The Ronald Lake herd became particular interest among researchers and conservationists due to its genetic uniqueness and
3723-430: The incorporation of silica into cell walls is analogous to that of the role of lignin in that it is a compression-resistant structural component of cell walls; so that plants with their cell walls impregnated with silica are thereby afforded a measure of protection against herbivory. Chemical defenses are secondary metabolites produced by the plant that deter herbivory. There are a wide variety of these in nature and
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#17328020637073796-406: The interaction of herbivory and plant defense is negative, with one individual reducing the fitness of the other, some is beneficial. This beneficial herbivory takes the form of mutualisms in which both partners benefit in some way from the interaction. Seed dispersal by herbivores and pollination are two forms of mutualistic herbivory in which the herbivore receives a food resource and the plant
3869-480: The introduction of wood bison into Yakutia , Russia, were first proposed by zoologists P. B. Yurgenson in 1961 and O. V. Egorov in 1963. Compared to the first reintroduction of muskoxen in 1996, an outherd of wood bison was established as part of an international conservation project in 2006, where the related steppe bison ( B. priscus ) died out over 6,000 years ago. Additional bison were sent from Elk Island National Park in 2011, 2013, and 2020 to Russia, bringing
3942-444: The larger free-ranging herds in and around Wood Buffalo National Park were infected with bovine brucellosis and tuberculosis after the plains bison had been translocated from Buffalo National Park. Diseases including brucellosis and tuberculosis remain endemic in the free-ranging herds in and around Wood Buffalo National Park. The diseases represent a serious management issue for governments, various local indigenous groups , and
4015-414: The local forage. Loss of functional habitat is a major ecological concern for this species due to the density-dependent nature of reproduction. Wood bison are herbivorous grazers that feed primarily on grasses , sedges , and forbs . Due to frequent and heavy snowfall in their native habitat, food availability fluctuates throughout the year, leading to a diverse and varied diet. Deep snow often creates
4088-407: The metabolic rate (q 0 ) of an animal is the mass of the animal (M) raised to the 3/4 power: q 0 =M Therefore, the mass of the animal increases at a faster rate than the metabolic rate. Herbivores employ numerous types of feeding strategies. Many herbivores do not fall into one specific feeding strategy, but employ several strategies and eat a variety of plant parts. Optimal foraging theory
4161-402: The patch quality. Interactions between plants and herbivores can play a prevalent role in ecosystem dynamics such community structure and functional processes. Plant diversity and distribution is often driven by herbivory, and it is likely that trade-offs between plant competitiveness and defensiveness , and between colonization and mortality allow for coexistence between species in
4234-570: The plant, or induced, produced or translocated by the plant following damage or stress. Physical, or mechanical, defenses are barriers or structures designed to deter herbivores or reduce intake rates, lowering overall herbivory. Thorns such as those found on roses or acacia trees are one example, as are the spines on a cactus. Smaller hairs known as trichomes may cover leaves or stems and are especially effective against invertebrate herbivores. In addition, some plants have waxes or resins that alter their texture, making them difficult to eat. Also
4307-538: The presence of herbivores. However, the effects of herbivory on plant diversity and richness is variable. For example, increased abundance of herbivores such as deer decrease plant diversity and species richness , while other large mammalian herbivores like bison control dominant species which allows other species to flourish. Plant-herbivore interactions can also operate so that plant communities mediate herbivore communities. Plant communities that are more diverse typically sustain greater herbivore richness by providing
4380-403: The production of large amounts of saliva to reduce effectiveness of defenses. Herbivores may also utilize symbionts to evade plant defenses. For example, some aphids use bacteria in their gut to provide essential amino acids lacking in their sap diet. Plant modification occurs when herbivores manipulate their plant prey to increase feeding. For example, some caterpillars roll leaves to reduce
4453-415: The remnant wood bisons were thought to be hybridized with the larger numbers of plains bisons. However, in 1957 a relatively pure herd of about 200 was discovered in an isolated part of Wood Buffalo National Park, although gene flows likely occurred elsewhere within the park when the herd was discovered, and this herd unlikely remained completely isolated and did not preserve pure genes and phenotype. Thus
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#17328020637074526-490: The section on Plant Defenses. Eating a second prey type helps herbivores' populations stabilize. Alternating between two or more plant types provides population stability for the herbivore, while the populations of the plants oscillate. This plays an important role for generalist herbivores that eat a variety of plants. Keystone herbivores keep vegetation populations in check and allow for a greater diversity of both herbivores and plants. When an invasive herbivore or plant enters
4599-556: The size of herbivores having an effect on the amount of energy intake that is needed, larger herbivores need to forage on higher quality or more plants to gain the optimal amount of nutrients and energy compared to smaller herbivores. Environmental degradation from white-tailed deer ( Odocoileus virginianus ) in the US alone has the potential to both change vegetative communities through over-browsing and cost forest restoration projects upwards of $ 750 million annually. Another example of
4672-527: The skills required to evade predators, such as running and kicking, on the same day they are born. Reproduction is limited by the amount of habitat available. Bison tend to disperse when there is not enough food to sustain a population within the current range, which causes a decrease in population density, indirectly lowering the rate at which mating occurs. Older bulls will typically have smaller ranges than female herds, because they live either solitarily or in smaller herds and therefore exert less pressure on
4745-453: The system, the balance is thrown off and the diversity can collapse to a monotaxon system. The back and forth relationship of plant defense and herbivore offense drives coevolution between plants and herbivores, resulting in a "coevolutionary arms race". The escape and radiation mechanisms for coevolution, presents the idea that adaptations in herbivores and their host plants, has been the driving force behind speciation . While much of
4818-485: The theme. The understanding of herbivory in geological time comes from three sources: fossilized plants, which may preserve evidence of defence (such as spines), or herbivory-related damage; the observation of plant debris in fossilised animal faeces ; and the construction of herbivore mouthparts. Although herbivory was long thought to be a Mesozoic phenomenon, fossils have shown that plants were being consumed by arthropods within less than 20 million years after
4891-421: The theory of predator –prey interactions, the relationship between herbivores and plants is cyclic. When prey (plants) are numerous their predators (herbivores) increase in numbers, reducing the prey population, which in turn causes predator number to decline. The prey population eventually recovers, starting a new cycle. This suggests that the population of the herbivore fluctuates around the carrying capacity of
4964-496: The total to over 120. A team of Russian and Korean scientists proposed a potential de-extinction of the steppe bison with wood bison in Siberia using cloning techniques. As of 2019, the number of bison increased to more than 210 animals, and a portion of the herd was released into the wild. To strengthen the restoration further, the Yakutia's Red List officially registered wood bison. In 2020, 10 juveniles were translocated into
5037-502: The winter months while areas in Yakutia, such as Oymyakon have been reported to drop as low as −71.2 °C. Despite the frigid temperatures, the bison herd is adapting well to the new environment. As with other bison, the wood bison's population was devastated by hunting, loss of habitat, and other factors. By the early 20th century, they were regarded as extremely rare. Wood bison populations have been susceptible to hybridization with illness-infected plains bison, thereby polluting
5110-623: The wood bison in the Wood Buffalo National Park are considered hybrid descendants. However, a study in 1995 detected that there have been notable differences among each herd within the park, showing different degrees of hybridization. The herd at the Sweetgrass Station near the Peace–Athabasca Delta , as well as the Slave River Lowlands herd, preserved phenotypes relatively loyal to the original wood bison before
5183-429: Was a gap of 50 to 100 million years between the time each organ evolved and the time organisms evolved to feed upon them; this may be due to the low levels of oxygen during this period, which may have suppressed evolution. Further than their arthropod status, the identity of these early herbivores is uncertain. Hole feeding and skeletonization are recorded in the early Permian , with surface fluid feeding evolving by
5256-431: Was composed of herbivorous dinosaurs. 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. Arthropods evolved herbivory in four phases, changing their approach to it in response to changing plant communities. Tetrapod herbivores made their first appearance in
5329-444: Was first recorded in 1774. The "eastern bison" ( B. b. pennsylvanicus ) from the eastern United States, a junior synonym of B. b. bison had been called "wood(s) bison" or "woodland bison", not referring to B. b. athabascae . The wood bison is potentially more primitive in phenotype than the plains bison ( Bison bison bison ), while the latter probably evolved from a mixing of Bison occidentalis and Bison antiquus . It
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