A generalist species is able to thrive in a wide variety of environmental conditions and can make use of a variety of different

resources ''Resource'' refers to all the materials available in our environment which are Technology, technologically accessible, Economics, economically feasible and Culture, culturally Sustainability, sustainable and help us to satisfy our needs and want ...

(for example, a

heterotroph A heterotroph (; ) is an organism that cannot produce its own food, instead taking nutrition from other sources of organic carbon, mainly plant or animal matter. In the food chain, heterotrophs are primary, secondary and tertiary consumers, but ...

with a varied

diet Diet may refer to: Food * Diet (nutrition), the sum of the food consumed by an organism or group * Dieting, the deliberate selection of food to control body weight or nutrient intake ** Diet food, foods that aid in creating a diet for weight loss ...

). A specialist species can thrive only in a narrow range of environmental conditions or has a limited diet. Most

organism An organism is any life, living thing that functions as an individual. Such a definition raises more problems than it solves, not least because the concept of an individual is also difficult. Many criteria, few of them widely accepted, have be ...

s do not all fit neatly into either group, however. Some species are highly specialized (the most extreme case being monophagous, eating one specific type of food), others less so, and some can tolerate many different environments. In other words, there is a continuum from highly specialized to broadly generalist species.

Description

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

s are usually generalists.

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 ...

s are often specialists, but those that eat a variety of plants may be considered generalists. A well-known example of a specialist animal is the monophagous

koala The koala (''Phascolarctos cinereus''), sometimes inaccurately called the koala bear, is an arboreal herbivorous marsupial native to Australia. It is the only Extant taxon, extant representative of the Family (biology), family ''Phascolar ...

, which subsists almost entirely on

eucalyptus ''Eucalyptus'' () is a genus of more than 700 species of flowering plants in the family Myrtaceae. Most species of ''Eucalyptus'' are trees, often Mallee (habit), mallees, and a few are shrubs. Along with several other genera in the tribe Eucalyp ...

leaves. The

raccoon The raccoon ( or , ''Procyon lotor''), sometimes called the North American, northern or common raccoon (also spelled racoon) to distinguish it from Procyonina, other species of raccoon, is a mammal native to North America. It is the largest ...

is a generalist, because it has a natural range that includes most of North and Central America, and it is omnivorous, eating

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 fruit, stone or pit (fruit), pit although many wikt:pip#Etymology 2, pips or seeds may be p ...

, insects such as butterflies, eggs, and various small animals. When it comes to insects, particularly native bees and

lepidoptera Lepidoptera ( ) or lepidopterans is an order (biology), order of winged insects which includes butterflies and moths. About 180,000 species of the Lepidoptera have been described, representing 10% of the total described species of living organ ...

(butterflies and moths), many are specialist species. It is estimated that about half of native US bee species are pollen specialists, meaning they collect resources from specific

genera Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...

. For instance, the threatened

monarch butterfly The monarch butterfly or simply monarch (''Danaus plexippus'') is a milkweed butterfly (subfamily Danainae) in the family Nymphalidae. Other common names, depending on region, include milkweed, common tiger, wanderer, and black-veined brown. I ...

exclusively lays its eggs on milkweed species. This reliance underscores the critical role of native plants in supporting ecological food chains. The distinction between generalists and specialists is not limited to animals. For example, some plants require a narrow range of temperatures, soil conditions and

precipitation In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls from clouds due to gravitational pull. The main forms of precipitation include drizzle, rain, rain and snow mixed ("sleet" in Commonwe ...

to survive while others can tolerate a broader range of conditions. A

cactus A cactus (: cacti, cactuses, or less commonly, cactus) is a member of the plant family Cactaceae (), a family of the order Caryophyllales comprising about 127 genera with some 1,750 known species. The word ''cactus'' derives, through Latin, ...

could be considered a specialist species. It will die during winters at high

latitude In geography, latitude is a geographic coordinate system, geographic coordinate that specifies the north-south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from −90° at t ...

s or if it receives too much water. When

body weight Human body weight is a person's mass or weight. Strictly speaking, body weight is the measurement of mass without items located on the person. Practically though, body weight may be measured with clothes on, but without shoes or heavy accessori ...

is controlled for, specialist feeders such as

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

s and

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 ...

s have larger

home range A home range is the area in which an animal lives and moves on a periodic basis. It is related to the concept of an animal's territory which is the area that is actively defended. The concept of a home range was introduced by W. H. Burt in 1943. ...

s than generalists like some

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

s (leaf-eaters), whose food-source is less abundant; they need a bigger area for

foraging Foraging is searching for wild food resources. It affects an animal's fitness because it plays an important role in an animal's ability to survive and reproduce. Foraging theory is a branch of behavioral ecology that studies the foraging behavi ...

. An example comes from the research of

Tim Clutton-Brock Timothy Hugh Clutton-Brock (born 13 August 1946) is a British zoologist known for his comparative studies of the behavioural ecology of mammals, particularly red deer and meerkats.black-and-white colobus Black-and-white colobuses (or colobi) are Old World monkeys of the genus ''Colobus'', native to Africa. They are closely related to the red colobus monkeys of genus '' Piliocolobus''. There are five species of this monkey, and at least eight subs ...

, a folivore generalist, needs a home range of only 15 ha. On the other hand, the more specialized

red colobus monkey Red colobuses are Old World monkeys of the genus ''Piliocolobus''. It was formerly considered a subgenus within the genus '' Procolobus'', which is now restricted to the olive colobus. They are closely related to the black-and-white colobus mon ...

has a home range of 70 ha, which it requires to find patchy shoots, flowers and fruit. When environmental conditions change, generalists are able to adapt, but specialists tend to fall victim to

extinction Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

much more easily. For example, if a species of fish were to go extinct, any specialist

parasite Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted str ...

s would also face extinction. On the other hand, a species with a highly specialized

ecological niche In ecology, a niche is the match of a species to a specific environmental condition. Three variants of ecological niche are described by It describes how an organism or population responds to the distribution of Resource (biology), resources an ...

is more effective at competing with other organisms. For example, a fish and its parasites are in an

evolutionary arms race In evolutionary biology, an evolutionary arms race is an ongoing struggle between competing sets of co-evolving genes, phenotypic and behavioral traits that develop escalating adaptations and counter-adaptations against each other, resembling the ...

, a form of

coevolution In biology, coevolution occurs when two or more species reciprocally affect each other's evolution through the process of natural selection. The term sometimes is used for two traits in the same species affecting each other's evolution, as well a ...

, in which the fish constantly develops defenses against the parasite, while the parasite in turn evolves adaptations to cope with the specific defenses of its host. This tends to drive the

speciation Speciation is the evolutionary process by which populations evolve to become distinct species. The biologist Orator F. Cook coined the term in 1906 for cladogenesis, the splitting of lineages, as opposed to anagenesis, phyletic evolution within ...

of more specialized species provided conditions remain relatively stable. This involves

niche partitioning In ecology, a niche is the match of a species to a specific environmental condition. Three variants of ecological niche are described by It describes how an organism or population responds to the distribution of resources and competitors (for e ...

as new species are formed, and

biodiversity Biodiversity is the variability of life, life on Earth. It can be measured on various levels. There is for example genetic variability, species diversity, ecosystem diversity and Phylogenetics, phylogenetic diversity. Diversity is not distribut ...

is increased. A benefit of a specialist species is that because the species has a more clearly defined niche, this reduces competition from other species. On the other hand, generalist species, by their nature, cannot realize as much resources from one niche, but instead find resources from many. Because other species can also be generalists, there is more competition between species, reducing the amount of resources for all generalists in an ecosystem. Specialist herbivores can have morphological differences as compared to generalists that allow them to be more efficient at hunting a certain prey item, or able to eat a plant that generalists would be less tolerant of.

References

https://www.webpages.uidaho.edu/range556/appl_behave/projects/different_strokes.html{{modelling ecosystems Ecology

Description

See also

References