Mating

In biology, mating (or mateing in British English) is the pairing of either opposite-sex or hermaphroditic organisms, usually for the purposes of sexual reproduction. Some definitions limit the term to pairing between animals,[1] while other definitions extend the term to mating in plants and fungi. Fertilization is the fusion of both sex cell or gamete.[2] Copulation is the union of the sex organs of two sexually reproducing animals for insemination and subsequent internal fertilization. Mating may also lead to external fertilization, as seen in amphibians, fishes and plants. For the majority of species, mating is between two individuals of opposite sexes. However, for some hermaphroditic species, copulation is not required because the parent organism is capable of self-fertilization (autogamy); for example, banana slugs.

The term mating is also applied to related processes in bacteria, archaea and viruses. Mating in these cases involves the pairing of individuals, accompanied by the pairing of their homologous chromosomes and then exchange of genomic information leading to formation of recombinant progeny (see mating systems).

Blue-tailed damselflies (Ischnura elegans) mating, female typica 2
Blue-tailed damselflies
(Ischnura elegans) mating

Animals

For animals, mating strategies include random mating, disassortative mating, assortative mating, or a mating pool. In some birds, it includes behaviors such as nest-building and feeding offspring. The human practice of mating and artificially inseminating domesticated animals is part of animal husbandry.

In some terrestrial arthropods, including insects representing basal (primitive) phylogenetic clades, the male deposits spermatozoa on the substrate, sometimes stored within a special structure. Courtship involves inducing the female to take up the sperm package into her genital opening without actual copulation. In groups such as dragonflies and many spiders, males extrude sperm into secondary copulatory structures removed from their genital opening, which are then used to inseminate the female (in dragonflies, it is a set of modified sternites on the second abdominal segment; in spiders, it is the male pedipalps). In advanced groups of insects, the male uses its aedeagus, a structure formed from the terminal segments of the abdomen, to deposit sperm directly (though sometimes in a capsule called a "spermatophore") into the female's reproductive tract.

Other animals reproduce sexually with external fertilization, including many basal vertebrates. Vertebrates (such as reptiles, some fish, and most birds) reproduce with internal fertilization through cloacal copulation (see also hemipenis), while mammals copulate vaginally.[3]

Tortoise mating

African spurred tortoises (Centrochelys sulcata) mating

Chalkhill blue butterflies (Polyommatus coridon) mating 1

Chalkhill blue butterflies (Polyommatus coridon) mating

Joined moths

Poplar hawk-moths (Laothoe populi) mating

Ladybird-Coccinellidae-mating

Ladybugs mating

Aphrophora alni mating

Spittlebugs (Aphrophora alni) mating

Plants and fungi

Like in animals, mating in other Eukaryotes, such as plants and fungi, denotes sexual conjugation. However, in vascular plants this is mostly achieved without physical contact between mating individuals (see pollination), and in some cases, e.g., in fungi no distinguishable male or female organs exist (see isogamy); however, mating types in some fungal species are somewhat analogous to sexual dimorphism in animals, and determine whether or not two individual isolates can mate. Yeasts are eukaryotic microorganisms classified in the kingdom Fungi, with 1,500 species currently described.[4] In general, under high stress conditions like nutrient starvation, haploid cells will die; under the same conditions, however, diploid cells of Saccharomyces cerevisiae can undergo sporulation, entering sexual reproduction (meiosis) and produce a variety of haploid spores, which can go on to mate (conjugate) and reform the diploid.[5]

Protists

Protists are a large group of diverse eukaryotic microorganisms, mainly unicellular animals and plants, that do not form tissues. Eukaryotes emerged in evolution more than 1.5 billion years ago.[6] The earliest eukaryotes were likely protists. Mating and sexual reproduction are widespread among extant eukaryotes including protists such as Paramecium and Chlamydomonas. In many eukaryotic species, mating is promoted by sex pheromones including the protist Blepharisma japonicum. Based on a phylogenetic analysis, Dacks and Roger[7] proposed that facultative sex was present in the common ancestor of all eukaryotes.

However, to many biologists it seemed unlikely until recently, that mating and sex could be a primordial and fundamental characteristic of eukaryotes. A principal reason for this view was that mating and sex appeared to be lacking in certain pathogenic protists whose ancestors branched off early from the eukaryotic family tree. However, several of these protists are now known to be capable of, or to recently have had, the capability for meiosis and hence mating. To cite one example, the common intestinal parasite Giardia intestinalis was once considered to be a descendant of a protist lineage that predated the emergence of meiosis and sex. However, G. intestinalis was recently found to have a core set of genes that function in meiosis and that are widely present among sexual eukaryotes.[8] These results suggested that G. intestinalis is capable of meiosis and thus mating and sexual reproduction. Furthermore, direct evidence for meiotic recombination, indicative of mating and sexual reproduction, was also found in G. intestinalis.[9][9] Other protists for which evidence of mating and sexual reproduction has recently been described are parasitic protozoa of the genus Leishmania,[10] Trichomonas vaginalis,[11] and acanthamoeba.[12]

Protists generally reproduce asexually under favorable environmental conditions, but tend to reproduce sexually under stressful conditions, such as starvation or heat shock.[13]

See also

References

  1. ^ The Free Dictionary. "Mate". Retrieved May 31, 2013.
  2. ^ The Free Dictionary. "'Fertilization' - definition of". Farlex, Inc. Retrieved 25 January 2014.
  3. ^ Libbie Henrietta Hyman (15 September 1992). Hyman's Comparative Vertebrate Anatomy. University of Chicago Press. ISBN 978-0-226-87013-7.
  4. ^ "What are yeasts?". Yeast Virtual Library. 13 September 2009. Archived from the original on 26 February 2009. Retrieved 28 November 2009.
  5. ^ Neiman, A.M. (2005). "Ascospore formation in the yeast Saccharomyces cerevisiae". Microbiology and Molecular Biology Reviews. 69 (4): 565–584. doi:10.1128/MMBR.69.4.565-584.2005. PMC 1306807. PMID 16339736.
  6. ^ Javaux EJ, Knoll AH, Walter MR (2001). "Morphological and ecological complexity in early eukaryotic ecosystems". Nature. 412 (6842): 66–9. doi:10.1038/35083562. PMID 11452306.
  7. ^ Dacks J, Roger AJ (1999). "The first sexual lineage and the relevance of facultative sex". J. Mol. Evol. 48 (6): 779–83. doi:10.1007/pl00013156. PMID 10229582.
  8. ^ Ramesh MA, Malik SB, Logsdon JM (2005). "A phylogenomic inventory of meiotic genes; evidence for sex in Giardia and an early eukaryotic origin of meiosis". Curr. Biol. 15 (2): 185–91. doi:10.1016/j.cub.2005.01.003. PMID 15668177.
  9. ^ a b Cooper MA, Adam RD, Worobey M, Sterling CR (2007). "Population genetics provides evidence for recombination in Giardia". Curr. Biol. 17 (22): 1984–8. doi:10.1016/j.cub.2007.10.020. PMID 17980591.
  10. ^ Akopyants NS, Kimblin N, Secundino N, Patrick R, Peters N, Lawyer P, Dobson DE, Beverley SM, Sacks DL (2009). "Demonstration of genetic exchange during cyclical development of Leishmania in the sand fly vector". Science. 324 (5924): 265–8. doi:10.1126/science.1169464. PMC 2729066. PMID 19359589.
  11. ^ Malik SB, Pightling AW, Stefaniak LM, Schurko AM, Logsdon JM (2008). "An expanded inventory of conserved meiotic genes provides evidence for sex in Trichomonas vaginalis". PLoS ONE. 3 (8): e2879. doi:10.1371/journal.pone.0002879. PMC 2488364. PMID 18663385.
  12. ^ Khan NA, Siddiqui R (2015). "Is there evidence of sexual reproduction (meiosis) in Acanthamoeba?". Pathog Glob Health. 109 (4): 193–5. doi:10.1179/2047773215Y.0000000009. PMC 4530557. PMID 25800982.
  13. ^ Bernstein H and Bernstein C (2013). Evolutionary Origin and Adaptive Function of Meiosis. In Meiosis: Bernstein C and Bernstein H, editors, InTech. ISBN 978-953-51-1197-9

External links

Animal sexual behaviour

Animal sexual behaviour takes many different forms, including within the same species. Common mating or reproductively motivated systems include monogamy, polygyny, polyandry, polygamy and promiscuity. Other sexual behaviour may be reproductively motivated (e.g. sex apparently due to duress or coercion and situational sexual behaviour) or non-reproductively motivated (e.g. interspecific sexuality, sexual arousal from objects or places, sex with dead animals, homosexual sexual behaviour, and bisexual sexual behaviour).

When animal sexual behaviour is reproductively motivated, it is often termed mating or copulation; for most non-human mammals, mating and copulation occur at oestrus (the most fertile period in the mammalian female's reproductive cycle), which increases the chances of successful impregnation. Some animal sexual behaviour involves competition, sometimes fighting, between multiple males. Females often select males for mating only if they appear strong and able to protect themselves. The male that wins a fight may also have the chance to mate with a larger number of females and will therefore pass on his genes to their offspring.Historically, it was believed that only humans and a small number of other species performed sexual acts other than for reproduction, and that animals' sexuality was instinctive and a simple "stimulus-response" behaviour. However, in addition to homosexual behaviours, a range of species masturbate and may use objects as tools to help them do so. Sexual behaviour may be tied more strongly to establishment and maintenance of complex social bonds across a population which support its success in non-reproductive ways. Both reproductive and non-reproductive behaviours can be related to expressions of dominance over another animal or survival within a stressful situation (such as sex due to duress or coercion).

Clasper

In biology, a clasper is a male anatomical structure found in some groups of animals, used in mating.

Male cartilaginous fish have claspers formed from the posterior portion of their pelvic fin which serve as intromittent organs used to channel semen into the female's cloaca during mating. The act of mating in some fish including sharks usually includes one of the claspers raised to allow water into the siphon through a specific orifice. The clasper is then inserted into the cloaca, where it opens like an umbrella to anchor its position. The siphon then begins to contract, expelling water and sperm. Male chimaeras have cephalic claspers (tenacula) on their heads, which are thought to aid in holding the female during mating.

In entomology, it is a structure in male insects that is used to hold the female during copulation (see Lepidoptera genitalia for more).

Courtship

Courtship is the period of development towards an intimate relationship wherein a couple get to know each other and decide if there will be an engagement. A courtship may be an informal and private matter between two people or may be a public affair, or a formal arrangement with family approval. Traditionally, in the case of a formal engagement, it has been perceived that it is the role of a male to actively "court" or "woo" a female, thus encouraging her to understand him and her receptiveness to a proposal of marriage.

Courtship display

A courtship display is a set of display behaviors in which an animal attempts to attract a mate and exhibit their desire to copulate. These behaviors often include ritualized movement ("dances"), vocalizations, mechanical sound production, or displays of beauty, strength, or agonistic ability.

Estrous cycle

The estrous cycle or oestrus cycle (derived from Latin oestrus 'frenzy', originally from Greek οἶστρος oîstros 'gadfly') is the recurring physiological changes that are induced by reproductive hormones in most mammalian therian females. Estrous cycles start after sexual maturity in females and are interrupted by anestrous phases or by pregnancies. Typically, estrous cycles continue until death. Some animals may display bloody vaginal discharge, often mistaken for menstruation.

Fallow deer

The fallow deer (Dama dama) is a ruminant mammal belonging to the family Cervidae. This common species is native to Europe, but has been introduced to Antigua & Barbuda, Argentina, South Africa, Fernando Pó, São Tomé, Madagascar, Mauritius, Mayotte, Réunion, Seychelles, Comoro Islands, Morocco, Algeria, Tunisia, Cyprus, Israel, Cape Verde, Lebanon, Australia, New Zealand, Canada, the United States, the Falkland Islands, and Peru. Some taxonomers include the rarer Persian fallow deer as a subspecies (D. d. mesopotamica), while others treat it as an entirely different species (D. mesopotamica).

Fossa (animal)

The fossa ( or ; Malagasy pronunciation: [ˈfusə̥]; Cryptoprocta ferox) is a cat-like, carnivorous mammal endemic to Madagascar. It is a member of the Eupleridae, a family of carnivorans closely related to the mongoose family (Herpestidae). Its classification has been controversial because its physical traits resemble those of cats, yet other traits suggest a close relationship with viverrids (most civets and their relatives). Its classification, along with that of the other Malagasy carnivores, influenced hypotheses about how many times mammalian carnivores have colonized Madagascar. With genetic studies demonstrating that the fossa and all other Malagasy carnivores are most closely related to each other (forming a clade, recognized as the family Eupleridae), carnivorans are now thought to have colonized the island once, around 18 to 20 million years ago.

The fossa is the largest mammalian carnivore on the island of Madagascar and has been compared to a small cougar. Adults have a head-body length of 70–80 cm (28–31 in) and weigh between 5.5 and 8.6 kg (12 and 19 lb), with the males larger than the females. It has semi-retractable claws (meaning it can extend but not retract its claws fully) and flexible ankles that allow it to climb up and down trees head-first, and also support jumping from tree to tree. The fossa is unique within its family for the shape of its genitalia, which share traits with those of cats and hyenas.

The species is widespread, although population densities are usually low. It is found solely in forested habitat, and actively hunts both by day and night. Over 50% of its diet consists of lemurs, the endemic primates found on the island; tenrecs, rodents, lizards, birds, and other animals are also documented as prey. Mating usually occurs in trees on horizontal limbs and can last for several hours. Litters range from one to six pups, which are born blind and toothless (altricial). Infants wean after 4.5 months and are independent after a year. Sexual maturity occurs around three to four years of age, and life expectancy in captivity is 20 years. The fossa is listed as a vulnerable species by the International Union for Conservation of Nature. It is generally feared by the Malagasy people and is often protected by their fady (taboo). The greatest threat to the species is habitat destruction.

Giraffe

The giraffe (Giraffa) is a genus of African even-toed ungulate mammals, the tallest living terrestrial animals and the largest ruminants. Taxonomic classifications of one to eight extant giraffe species have been described, based upon research into the mitochondrial and nuclear DNA, as well as morphological measurements of Giraffa, but the International Union for Conservation of Nature currently recognises only one species, Giraffa camelopardalis, the type species, with nine subspecies. Seven other species are extinct, prehistoric species known from fossils.

The giraffe's chief distinguishing characteristics are its extremely long neck and legs, its horn-like ossicones, and its distinctive coat patterns. It is classified under the family Giraffidae, along with its closest extant relative, the okapi. Its scattered range extends from Chad in the north to South Africa in the south, and from Niger in the west to Somalia in the east. Giraffes usually inhabit savannahs and woodlands. Their food source is leaves, fruits and flowers of woody plants, primarily acacia species, which they browse at heights most other herbivores cannot reach. They may be preyed on by lions, leopards, spotted hyenas and African wild dogs. Giraffes live in herds of related females and their offspring, or bachelor herds of unrelated adult males, but are gregarious and may gather in large aggregations. Males establish social hierarchies through "necking", which are combat bouts where the neck is used as a weapon. Dominant males gain mating access to females, which bear the sole responsibility for raising the young.

The giraffe has intrigued various cultures, both ancient and modern, for its peculiar appearance, and has often been featured in paintings, books, and cartoons. It is classified by the International Union for Conservation of Nature as Vulnerable to extinction, and has been extirpated from many parts of its former range. Giraffes are still found in numerous national parks and game reserves but estimations as of 2016 indicate that there are approximately 97,500 members of Giraffa in the wild. More than 1,600 were kept in zoos in 2010.

Human mating strategies

In evolutionary psychology and behavioral ecology, human mating strategies are a set of behaviors used by individuals to attract, select, and retain mates. Mating strategies overlap with reproductive strategies, which encompass a broader set of behaviors involving the timing of reproduction and the trade-off between quantity and quality of offspring (see life history theory).

Relative to other animals, human mating strategies are unique in their relationship with cultural variables such as the institution of marriage. Humans may seek out individuals with the intention of forming a long-term intimate relationship, marriage, casual relationship, or friendship. The human desire for companionship is one of the strongest human drives. It is an innate feature of human nature, and may be related to the sex drive. The human mating process encompasses the social and cultural processes whereby one person may meet another to assess suitability, the courtship process and the process of forming an interpersonal relationship. Commonalities, however, can be found between humans and nonhuman animals in mating behavior (see animal sexual behavior).

Hyena

Hyenas or hyaenas (from Greek ὕαινα hýaina) are any feliform carnivoran mammals of the family Hyaenidae . With only four extant species (in three genera), it is the fifth-smallest biological family in the Carnivora, and one of the smallest in the class Mammalia. Despite their low diversity, hyenas are unique and vital components of most African ecosystems.Although phylogenetically they are closer to felines and viverrids, and belong to the feliform category, hyenas are behaviourally and morphologically similar to canines in several elements of convergent evolution; both hyenas and canines are non-arboreal, cursorial hunters that catch prey with their teeth rather than claws. Both eat food quickly and may store it, and their calloused feet with large, blunt, nonretractable claws are adapted for running and making sharp turns. However, the hyenas' grooming, scent marking, defecating habits, mating and parental behaviour are consistent with the behaviour of other feliforms.Spotted hyenas may kill as many as 95% of the animals they eat, while striped hyenas are largely scavengers. Generally, hyenas are known to drive off larger predators, like lions, from their kills, despite having a reputation in popular culture for being cowardly. Hyenas are primarily nocturnal animals, but sometimes venture from their lairs in the early-morning hours. With the exception of the highly social spotted hyena, hyenas are generally not gregarious animals, though they may live in family groups and congregate at kills.Hyenas first arose in Eurasia during the Miocene period from viverrid-like ancestors, and diversified into two distinct types: lightly built dog-like hyenas and robust bone-crushing hyenas. Although the dog-like hyenas thrived 15 million years ago (with one taxon having colonised North America), they became extinct after a change in climate along with the arrival of canids into Eurasia. Of the dog-like hyena lineage, only the insectivorous aardwolf survived, while the bone-crushing hyenas (including the extant spotted, brown and striped hyenas) became the undisputed top scavengers of Eurasia and Africa.Hyenas feature prominently in the folklore and mythology of human cultures that live alongside them. Hyenas are commonly viewed as frightening and worthy of contempt. In some cultures, hyenas are thought to influence people’s spirits, rob graves, and steal livestock and children. Other cultures associate them with witchcraft, using their body parts in traditional African medicine.

Hypergamy

Hypergamy (colloquially referred to as "marrying up" or "gold-digging", occasionally referred to as "higher-gamy") is a term used in social science for the act or practice of a person marrying a spouse of higher caste or social status than themselves.

The antonym "hypogamy" refers to the inverse: marrying a person of lower social class or status (colloquially "marrying down").

Both terms were coined in the Indian subcontinent in the 19th century while translating classical Hindu law books, which used the Sanskrit terms anuloma and pratiloma, respectively, for the two concepts.

Lek mating

A lek is an aggregation of male animals gathered to engage in competitive displays, lekking, to entice visiting females which are surveying prospective partners for copulation. Leks are commonly formed before or during the breeding season. A lekking species is characterised by male displays, strong female mate choice, and the conferring of indirect benefits to males. Although most prevalent among birds such as black grouse, lekking is also found in insects including paper wasps, crustaceans, fishes, amphibians, reptiles and mammals.

A classical lek consists of male territories in visual and auditory range of each other. An exploded lek, as seen in the kakapo (the owl parrot), has more widely separated territories, but still in auditory range.

Lekking is associated with an apparent paradox: strong sexual selection by females for specific male traits ought to erode genetic diversity by Fisherian runaway, but diversity is maintained and runaway does not occur. Many attempts have been made to explain it away, but the paradox remains.

Leopard

The leopard (Panthera pardus) is one of the five extant species in the genus Panthera, a member of the Felidae. It occurs in a wide range in sub-Saharan Africa, in small parts of Western Asia, on the Indian subcontinent to Southeast and East Asia. It is listed as Vulnerable on the IUCN Red List because leopard populations are threatened by habitat loss and fragmentation, and are declining in large parts of the global range. In Hong Kong, Singapore, Kuwait, Syria, Libya, Tunisia and most likely in Morocco, leopard populations have already been extirpated.

Contemporary records suggest that the leopard occurs in only 25% of its historical global range.

Leopards are hunted illegally, and their body parts are smuggled in the wildlife trade for medicinal practices and decoration.Compared to other wild cats, the leopard has relatively short legs and a long body with a large skull. Its fur is marked with rosettes. It is similar in appearance to the jaguar, but has a smaller, lighter physique, and its rosettes are generally smaller, more densely packed and without central spots. Both leopards and jaguars that are melanistic are known as black panthers. The leopard is distinguished by its well-camouflaged fur, opportunistic hunting behaviour, broad diet, strength, and its ability to adapt to a variety of habitats ranging from rainforest to steppe, including arid and montane areas. It can run at speeds of up to 58 kilometres per hour (36 mph). The earliest known leopard fossils excavated in Europe are estimated 600,000 years old, dating to the late Early Pleistocene. Leopard fossils were also found in Japan.

Mating type

Mating types are molecular mechanisms that regulate compatibility in sexually reproducing eukaryotes. They occur in isogamous and anisogamous species. Depending on the group, different mating types are often referred to by numbers, letters, or simply "+" and "-" instead of "male" and "female", that refer to "sexes" or differences in size between gametes. Syngamy can only take place between gametes carrying different mating types.

Reproduction regulated by mating types is especially prevalent in fungi. Filamentous ascomycetes usually have two mating types referred to as "MAT1-1" and "MAT1-2", following the yeast mating type locus MAT. Under standard nomenclature, MAT1-1 (which may informally be called MAT1) encodes for a regulatory protein with a high motility-group (HMG) DNA-binding motif, while MAT1-2 (informally called MAT2) encodes for a protein with an alpha box motif, as in the yeast mating type MATα1. The corresponding mating types in yeast, a non-filamentous ascomycete, are referred to as MATa and MATα.

Mating type genes in ascomycetes are called idiomorphs rather than alleles due to the uncertainty of the origin by common descent. The proteins they encode are transcription factors that regulate both the early and late stages of the sexual cycle. Heterothallic ascomycetes produce gametes that present a single Mat idiomorph and syngamy will only be possible between gametes carrying complementary mating types. On the other hand, homothallic ascomycetes produce gametes that can fuse with every other gamete in the population (including its own mitotic descendants) most often because each haploid contains the two alternate forms of the Mat locus in its genome.Basidiomycetes on the other hand can have thousands of different mating types.The adaptive function of mating type in the ascomycete Neurospora crassa is discussed in the article Neurospora crassa. That matings in N. crassa are restricted to interaction of strains of opposite mating type may be an adaptation to promote some degree of outcrossing. Outcrossing, through complementation, could provide the benefit of masking recessive deleterious mutations in genes that function in the dikaryon and/or diploid stage of the life cycle.

Seasonal breeder

Seasonal breeders are animal species that successfully mate only during certain times of the year. These times of year allow for the optimization of survival of young due to factors such as ambient temperature, food and water availability, and changes in the predation behaviors of other species. Related sexual interest and behaviors are expressed and accepted only during this period. Female seasonal breeders will have one or more estrus cycles only when she is "in season" or fertile and receptive to mating. At other times of the year, they will be anestrus, or have a dearth of their sexual cycle. Unlike reproductive cyclicity, seasonality is described in both males and females. Male seasonal breeders may exhibit changes in testosterone levels, testes weight, and fertility depending on the time of year.Seasonal breeders are distinct from opportunistic breeders, that mate whenever the conditions of their environment become favorable, and continuous breeders, like humans, that mate year-round.

Sex

Organisms of many species are specialized into male and female varieties, each known as a sex. Sexual reproduction involves the combining and mixing of genetic traits: specialized cells known as gametes combine to form offspring that inherit traits from each parent. The gametes produced by an organism define its sex: males produce small gametes (e.g. spermatozoa, or sperm, in animals; pollen in seed plants) while females produce large gametes (ova, or egg cells). Individual organisms which produce both male and female gametes are termed hermaphroditic. Gametes can be identical in form and function (known as isogamy), but, in many cases, an asymmetry has evolved such that two different types of gametes (heterogametes) exist (known as anisogamy).

Physical differences are often associated with the different sexes of an organism; these sexual dimorphisms can reflect the different reproductive pressures the sexes experience. For instance, mate choice and sexual selection can accelerate the evolution of physical differences between the sexes.

Among humans and other mammals, males typically carry an X and a Y chromosome (XY), whereas females typically carry two X chromosomes (XX), which are a part of the XY sex-determination system. Humans may also be intersex. Other animals have different sex-determination systems, such as the ZW system in birds, the X0 system in insects, and various environmental systems, for example in crustaceans. Fungi may also have more complex allelic mating systems, with sexes not accurately described as male, female, or hermaphroditic.

Ursus (genus)

Ursus is a genus in the family Ursidae (bears) that includes the widely distributed brown bear, the polar bear,the American black bear, and the

Asian black bear. The name is derived from the Latin ursus, meaning bear.

Vole

Voles are small rodents that are relatives of mice, but with a stouter body; a shorter, hairy tail; a slightly rounder head; smaller ears and eyes; and differently formed molars (high-crowned with angular cusps instead of low-crowned with rounded cusps). They are sometimes known as meadow mice or field mice in North America and Australia.

Vole species form the subfamily Arvicolinae with the lemmings and the muskrats. There are approximately 155 different vole species.

Wolf

The wolf (Canis lupus), also known as the gray/grey wolf, timber wolf,or tundra wolf, is a canine native to the wilderness and remote areas of Eurasia and North America. It is the largest extant member of its family, with males averaging 43–45 kg (95–99 lb) and females 36–38.5 kg (79–85 lb). It is distinguished from other Canis species by its larger size and less pointed features, particularly on the ears and muzzle. Its winter fur is long and bushy and predominantly a mottled gray in color, although nearly pure white, red and brown to black also occur. Mammal Species of the World (3rd ed., 2005), a standard reference work in zoology, recognises 38 subspecies of C. lupus.The gray wolf is the second most specialized member of the genus Canis, after the Ethiopian wolf, as demonstrated by its morphological adaptations to hunting large prey, its more gregarious nature, and its highly advanced expressive behavior. It is nonetheless closely related enough to smaller Canis species, such as the coyote and golden jackal, to produce fertile hybrids. It is the only species of Canis to have a range encompassing both Eurasia and North America, and originated in Eurasia during the Pleistocene, colonizing North America on at least three separate occasions during the Rancholabrean. It is a social animal, travelling in nuclear families consisting of a mated pair, accompanied by the pair's adult offspring. The gray wolf is typically an apex predator throughout its range, with only humans and tigers posing a serious threat to it. It feeds primarily on large ungulates, though it also eats smaller animals, livestock, carrion, and garbage. A seven-year-old wolf is considered to be relatively old, and the maximum lifespan is about 16 years.The global gray wolf population is estimated to be 300,000. The gray wolf is one of the world's best-known and most-researched animals, with probably more books written about it than any other wildlife species. It has a long history of association with humans, having been despised and hunted in most pastoral communities because of its attacks on livestock, while conversely being respected in some agrarian and hunter-gatherer societies. Although the fear of wolves is pervasive in many human societies, the majority of recorded attacks on people have been attributed to animals suffering from rabies. Non-rabid wolves have attacked and killed people, mainly children, but this is rare, as wolves are relatively few, live away from people, and have developed a fear of humans from hunters and shepherds.

This page is based on a Wikipedia article written by authors (here).
Text is available under the CC BY-SA 3.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.