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99-478: The Aesculapian snake / ˌ ɛ s k j ə ˈ l eɪ p i ə n / (now Zamenis longissimus , previously Elaphe longissima ) is a species of nonvenomous snake native to Europe, a member of the Colubrinae subfamily of the family Colubridae . Growing up to 2 metres (6.6 ft) in length, it is among the largest European snakes, similar in size to the four-lined snake ( Elaphe quatuorlineata ) and

198-423: A mutation–selection balance . It is predicted that a viral quasispecies at a low but evolutionarily neutral and highly connected (that is, flat) region in the fitness landscape will outcompete a quasispecies located at a higher but narrower fitness peak in which the surrounding mutants are unfit, "the quasispecies effect" or the "survival of the flattest". There is no suggestion that a viral quasispecies resembles

297-400: A "classical" method of determining species, such as with Linnaeus, early in evolutionary theory. However, different phenotypes are not necessarily different species (e.g. a four-winged Drosophila born to a two-winged mother is not a different species). Species named in this manner are called morphospecies . In the 1970s, Robert R. Sokal , Theodore J. Crovello and Peter Sneath proposed

396-424: A 'smallest clade' idea" (a phylogenetic species concept). Mishler and Wilkins and others concur with this approach, even though this would raise difficulties in biological nomenclature. Wilkins cited the ichthyologist Charles Tate Regan 's early 20th century remark that "a species is whatever a suitably qualified biologist chooses to call a species". Wilkins noted that the philosopher Philip Kitcher called this

495-457: A chewing-like movement of the mouth and occasionally biting. It has been speculated that the species may be more prevalent than thought due to spending a significant part of its time in tree canopy, but no reliable data exist as to what part that would be. In France it is said to be the only snake species that occurs inside dense, shadowy forests with minimum undergrowth, presumably because of using foliage for basking and foraging. In other parts of

594-428: A connected series of neighbouring populations, each of which can sexually interbreed with adjacent related populations, but for which there exist at least two "end" populations in the series, which are too distantly related to interbreed, though there is a potential gene flow between each "linked" population. Such non-breeding, though genetically connected, "end" populations may co-exist in the same region thus closing

693-861: A degree of activity even during hibernation, moving around to keep a body temperature near 5 °C (41 °F) and occasionally emerging to bask on sunny days. The average home range for French populations has been calculated at 1.14 ha (2.8 acres), however males will travel longer distances of up to 2 km (1.2 mi) to find females during the mating season and females to find suitable hatching sites to lay eggs. The Aesculapian snakes are deemed secretive and not always easy to find even in areas of positive presence, or found in surprising contexts. In contact with humans, they can be rather tame, possibly due to their cryptic coloration keeping them hidden within their natural environment. They usually disappear and hide, but if cornered they may sometimes stand their ground and try to intimidate their opponent, sometimes with

792-432: A different species from its ancestors. Viruses have enormous populations, are doubtfully living since they consist of little more than a string of DNA or RNA in a protein coat, and mutate rapidly. All of these factors make conventional species concepts largely inapplicable. A viral quasispecies is a group of genotypes related by similar mutations, competing within a highly mutagenic environment, and hence governed by

891-445: A divided anal scale , and 60-91 paired subcaudal scales (Schultz 1996; Arnold 2002). Ventral scales are sharply angled where the underside meets the side of the body, which enhances the species' climbing ability. Lifespan is estimated at 25 to 30 years. The contiguous area of the previous nominotypical subspecies , Zamenis longissimus longissimus , which is now the only recognized monotypic form, covers most of France except in

990-508: A genetic boundary suitable for defining a species concept is present. DNA barcoding has been proposed as a way to distinguish species suitable even for non-specialists to use. One of the barcodes is a region of mitochondrial DNA within the gene for cytochrome c oxidase . A database, Barcode of Life Data System , contains DNA barcode sequences from over 190,000 species. However, scientists such as Rob DeSalle have expressed concern that classical taxonomy and DNA barcoding, which they consider

1089-465: A lineage should be divided into multiple chronospecies , or when populations have diverged to have enough distinct character states to be described as cladistic species. Species and higher taxa were seen from the time of Aristotle until the 18th century as categories that could be arranged in a hierarchy, the great chain of being . In the 19th century, biologists grasped that species could evolve given sufficient time. Charles Darwin 's 1859 book On

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1188-492: A misnomer, need to be reconciled, as they delimit species differently. Genetic introgression mediated by endosymbionts and other vectors can further make barcodes ineffective in the identification of species. A phylogenetic or cladistic species is "the smallest aggregation of populations (sexual) or lineages (asexual) diagnosable by a unique combination of character states in comparable individuals (semaphoronts)". The empirical basis – observed character states – provides

1287-449: A particular species, including which genus (and higher taxa) it is placed in, is a hypothesis about the evolutionary relationships and distinguishability of that group of organisms. As further information comes to hand, the hypothesis may be corroborated or refuted. Sometimes, especially in the past when communication was more difficult, taxonomists working in isolation have given two distinct names to individual organisms later identified as

1386-400: A perfect model of life, it is still a useful tool to scientists and conservationists for studying life on Earth, regardless of the theoretical difficulties. If species were fixed and clearly distinct from one another, there would be no problem, but evolutionary processes cause species to change. This obliges taxonomists to decide, for example, when enough change has occurred to declare that

1485-400: A short way of saying that something applies to many species within a genus, but not to all. If scientists mean that something applies to all species within a genus, they use the genus name without the specific name or epithet. The names of genera and species are usually printed in italics . However, abbreviations such as "sp." should not be italicised. When a species' identity is not clear,

1584-404: A specialist may use "cf." before the epithet to indicate that confirmation is required. The abbreviations "nr." (near) or "aff." (affine) may be used when the identity is unclear but when the species appears to be similar to the species mentioned after. With the rise of online databases, codes have been devised to provide identifiers for species that are already defined, including: The naming of

1683-523: A species as groups of actually or potentially interbreeding natural populations, which are reproductively isolated from other such groups. It has been argued that this definition is a natural consequence of the effect of sexual reproduction on the dynamics of natural selection. Mayr's use of the adjective "potentially" has been a point of debate; some interpretations exclude unusual or artificial matings that occur only in captivity, or that involve animals capable of mating but that do not normally do so in

1782-400: A species as determined by a taxonomist. A typological species is a group of organisms in which individuals conform to certain fixed properties (a type), so that even pre-literate people often recognise the same taxon as do modern taxonomists. The clusters of variations or phenotypes within specimens (such as longer or shorter tails) would differentiate the species. This method was used as

1881-488: A species. All species definitions assume that an organism acquires its genes from one or two parents very like the "daughter" organism, but that is not what happens in HGT. There is strong evidence of HGT between very dissimilar groups of prokaryotes , and at least occasionally between dissimilar groups of eukaryotes , including some crustaceans and echinoderms . The evolutionary biologist James Mallet concludes that there

1980-685: A species. Generally the term includes the unknown element of a distinct act of creation. Many authors have argued that a simple textbook definition, following Mayr's concept, works well for most multi-celled organisms , but breaks down in several situations: Species identification is made difficult by discordance between molecular and morphological investigations; these can be categorised as two types: (i) one morphology, multiple lineages (e.g. morphological convergence , cryptic species ) and (ii) one lineage, multiple morphologies (e.g. phenotypic plasticity , multiple life-cycle stages). In addition, horizontal gene transfer (HGT) makes it difficult to define

2079-519: A taxonomic decision at the discretion of cognizant specialists, is not governed by the Codes of Zoological or Botanical Nomenclature, in contrast to the PhyloCode , and contrary to what is done in several other fields, in which the definitions of technical terms, like geochronological units and geopolitical entities, are explicitly delimited. The nomenclatural codes that guide the naming of species, including

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2178-653: A threat mainly to juveniles and hatches are domestic animals such as cats, dogs, and chickens, and even rats may be dangerous to inactive adult specimens in hibernation. In areas of concurrent distribution, they are also preyed upon by introduced North American raccoons and east Asian raccoon dogs . The snakes are active by day. In the warmer months of the year, they come out in late afternoon or early morning. They are very good climbers capable of ascending even vertical, branchless tree trunks. The snakes have been observed at heights of 4 to 5 m (13 to 16 ft) and even 15 to 20 m (49 to 66 ft) in trees, and foraging in

2277-506: A traditional biological species. The International Committee on Taxonomy of Viruses has since 1962 developed a universal taxonomic scheme for viruses; this has stabilised viral taxonomy. Most modern textbooks make use of Ernst Mayr 's 1942 definition, known as the Biological Species Concept as a basis for further discussion on the definition of species. It is also called a reproductive or isolation concept. This defines

2376-447: A variation on the morphological species concept, a phenetic species, defined as a set of organisms with a similar phenotype to each other, but a different phenotype from other sets of organisms. It differs from the morphological species concept in including a numerical measure of distance or similarity to cluster entities based on multivariate comparisons of a reasonably large number of phenotypic traits. A mate-recognition species

2475-431: A variety of hiding and basking places. The synanthropic aspect appears to be more pronounced in northernmost parts of the range where they are dependent on human structures for food, warmth and hatching grounds. They avoid open plains and agricultural deserts. In the south their range seems to coincide with the borderline between deciduous broadleaf forests and Mediterranean shrublands, with the latter presumably too dry for

2574-515: A variety of reasons. Viruses are a special case, driven by a balance of mutation and selection , and can be treated as quasispecies . Biologists and taxonomists have made many attempts to define species, beginning from morphology and moving towards genetics . Early taxonomists such as Linnaeus had no option but to describe what they saw: this was later formalised as the typological or morphological species concept. Ernst Mayr emphasised reproductive isolation, but this, like other species concepts,

2673-667: A wider sense corresponds to the western part of the Mid-Carpathian Depression and to the westernmost part of the Polonynian Beskids. Settled in prehistoric times, the south-eastern Poland region that is now Bieszczady was overrun in pre-Roman times by various tribes, including the Celts , Goths and Vandals ( Przeworsk culture and Puchov culture ). After the fall of the Roman Empire, of which most of south-eastern Poland

2772-484: A yellow collar on the neck that may persist for some time in younger adults. Juvenile Z. longissimus are light green or brownish-green with various darker patterns along the flanks and on the back. Two darker patches appear in the form of lines running on the top of the flanks. The head in juveniles also features several distinctive dark spots, one hoof-like on the back of the head in-between the yellow neck stripes, and two paired ones, with one horizontal stripe running from

2871-438: Is "an entity composed of organisms which maintains its identity from other such entities through time and over space, and which has its own independent evolutionary fate and historical tendencies". This differs from the biological species concept in embodying persistence over time. Wiley and Mayden stated that they see the evolutionary species concept as "identical" to Willi Hennig 's species-as-lineages concept, and asserted that

2970-400: Is a group of sexually reproducing organisms that recognise one another as potential mates. Expanding on this to allow for post-mating isolation, a cohesion species is the most inclusive population of individuals having the potential for phenotypic cohesion through intrinsic cohesion mechanisms; no matter whether populations can hybridise successfully, they are still distinct cohesion species if

3069-452: Is a population of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring , typically by sexual reproduction . It is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity . Other ways of defining species include their karyotype , DNA sequence, morphology , behaviour, or ecological niche . In addition, paleontologists use

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3168-458: Is a set of organisms adapted to a particular set of resources, called a niche, in the environment. According to this concept, populations form the discrete phenetic clusters that we recognise as species because the ecological and evolutionary processes controlling how resources are divided up tend to produce those clusters. A genetic species as defined by Robert Baker and Robert Bradley is a set of genetically isolated interbreeding populations. This

3267-414: Is called speciation . Charles Darwin was the first to describe the role of natural selection in speciation in his 1859 book The Origin of Species . Speciation depends on a measure of reproductive isolation , a reduced gene flow. This occurs most easily in allopatric speciation, where populations are separated geographically and can diverge gradually as mutations accumulate. Reproductive isolation

3366-412: Is called the specific name or the specific epithet (in botanical nomenclature , also sometimes in zoological nomenclature ). For example, Boa constrictor is one of the species of the genus Boa , with constrictor being the species' epithet. While the definitions given above may seem adequate at first glance, when looked at more closely they represent problematic species concepts. For example,

3465-403: Is described formally, in a publication that assigns it a unique scientific name. The description typically provides means for identifying the new species, which may not be based solely on morphology (see cryptic species ), differentiating it from other previously described and related or confusable species and provides a validly published name (in botany) or an available name (in zoology) when

3564-558: Is due. The snake has been classified as Critically Endangered in the German Red List of endangered species. In most other countries including France, Switzerland, Austria, the Czech Republic, Slovakia, Hungary, Bulgaria, Poland, Ukraine and Russia it is also under protection status. Among the key concerns is human-caused habitat destruction , with a series of respective recommendations concerning forestry and agriculture as to

3663-455: Is especially vulnerable in fringe parts and northern areas of its distribution where, given the historic retreat as a result of climatic changes since the Holocene climatic optimum, local populations remain isolated both from each other and from the main distribution centers, with no exchange of genetic material and no reinforcement through migration as a result. In such areas active local protection

3762-671: Is further weakened by the existence of microspecies , groups of organisms, including many plants, with very little genetic variability, usually forming species aggregates . For example, the dandelion Taraxacum officinale and the blackberry Rubus fruticosus are aggregates with many microspecies—perhaps 400 in the case of the blackberry and over 200 in the dandelion, complicated by hybridisation , apomixis and polyploidy , making gene flow between populations difficult to determine, and their taxonomy debatable. Species complexes occur in insects such as Heliconius butterflies, vertebrates such as Hypsiboas treefrogs, and fungi such as

3861-726: Is hard or even impossible to test. Later biologists have tried to refine Mayr's definition with the recognition and cohesion concepts, among others. Many of the concepts are quite similar or overlap, so they are not easy to count: the biologist R. L. Mayden recorded about 24 concepts, and the philosopher of science John Wilkins counted 26. Wilkins further grouped the species concepts into seven basic kinds of concepts: (1) agamospecies for asexual organisms (2) biospecies for reproductively isolated sexual organisms (3) ecospecies based on ecological niches (4) evolutionary species based on lineage (5) genetic species based on gene pool (6) morphospecies based on form or phenotype and (7) taxonomic species,

3960-403: Is no easy way to tell whether related geographic or temporal forms belong to the same or different species. Species gaps can be verified only locally and at a point of time. One is forced to admit that Darwin's insight is correct: any local reality or integrity of species is greatly reduced over large geographic ranges and time periods. The botanist Brent Mishler argued that the species concept

4059-468: Is not valid, notably because gene flux decreases gradually rather than in discrete steps, which hampers objective delimitation of species. Indeed, complex and unstable patterns of gene flux have been observed in cichlid teleosts of the East African Great Lakes . Wilkins argued that "if we were being true to evolution and the consequent phylogenetic approach to taxa, we should replace it with

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4158-586: Is similar to Mayr's Biological Species Concept, but stresses genetic rather than reproductive isolation. In the 21st century, a genetic species could be established by comparing DNA sequences. Earlier, other methods were available, such as comparing karyotypes (sets of chromosomes ) and allozymes ( enzyme variants). An evolutionarily significant unit (ESU) or "wildlife species" is a population of organisms considered distinct for purposes of conservation. In palaeontology , with only comparative anatomy (morphology) and histology from fossils as evidence,

4257-616: Is sometimes an important source of genetic variation. Viruses can transfer genes between species. Bacteria can exchange plasmids with bacteria of other species, including some apparently distantly related ones in different phylogenetic domains , making analysis of their relationships difficult, and weakening the concept of a bacterial species. Bieszczady Mountains Upper parties of Bieszczady are covered with montane meadows called polonyna (Ukrainian: полонина ; Polish: połonina ; Slovak: polonina ). The term Bieszczady has been introduced into English from Polish. In Poland,

4356-509: Is the term being related to Middle Low German beshêt , beskēt , meaning watershed . Since there exist many variants of divisions of the mountain ranges and names for the Eastern Beskids (and Ukrainian Carpathians in general), several divisions are given in the following: Division 1: Division 2: Division 3: In an old Ukrainian division, what is defined here as the Bieszczady in

4455-594: Is threatened by hybridisation, but this can be selected against once a pair of populations have incompatible alleles of the same gene, as described in the Bateson–Dobzhansky–Muller model . A different mechanism, phyletic speciation, involves one lineage gradually changing over time into a new and distinct form (a chronospecies ), without increasing the number of resultant species. Horizontal gene transfer between organisms of different species, either through hybridisation , antigenic shift , or reassortment ,

4554-523: The ICZN for animals and the ICN for plants, do not make rules for defining the boundaries of the species. Research can change the boundaries, also known as circumscription, based on new evidence. Species may then need to be distinguished by the boundary definitions used, and in such cases the names may be qualified with sensu stricto ("in the narrow sense") to denote usage in the exact meaning given by an author such as

4653-603: The Pleistocene . There are three populations of Aesculapian snake, descendants of escapees, in Great Britain . The oldest recorded of these is on the grounds and in the vicinity of the Welsh Mountain Zoo , near Conwy , North Wales . This population has survived and consistently reproduced since at least the early 1970s, and, in 2022, the population was estimated at 70 adults. A second, more recently established population

4752-399: The fly agaric . Natural hybridisation presents a challenge to the concept of a reproductively isolated species, as fertile hybrids permit gene flow between two populations. For example, the carrion crow Corvus corone and the hooded crow Corvus cornix appear and are classified as separate species, yet they can hybridise where their geographical ranges overlap. A ring species is

4851-498: The jaguar ( Panthera onca ) of Latin America or the leopard ( Panthera pardus ) of Africa and Asia. In contrast, the scientific names of species are chosen to be unique and universal (except for some inter-code homonyms ); they are in two parts used together : the genus as in Puma , and the specific epithet as in concolor . A species is given a taxonomic name when a type specimen

4950-406: The "cynical species concept", and arguing that far from being cynical, it usefully leads to an empirical taxonomy for any given group, based on taxonomists' experience. Other biologists have gone further and argued that we should abandon species entirely, and refer to the "Least Inclusive Taxonomic Units" (LITUs), a view that would be coherent with current evolutionary theory. The species concept

5049-565: The 9th century. This area was mentioned for the first time in 981, when Volodymyr the Great of Kievan Rus took the area over on the way into Poland. In 1018 it returned to Poland, 1031 back to Rus, in 1340 Casimir III of Poland recovered it. Bieszczady was one of the strategically important areas of the Carpathian mountains bitterly contested in battles on the Eastern Front of World War I during

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5148-486: The Montpellier snake ( Malpolon monspessulanus ). The Aesculapian snake has been of cultural and historical significance for its role in ancient Greek, Roman and Illyrian mythology and derived symbolism. Z. longissimus hatches at around 30 cm (11.8 in). Adults are usually from 110 cm (43.3 in) to 160 cm (63 in) in total length (including tail), but can grow to 200 cm (79 in), with

5247-622: The Origin of Species explained how species could arise by natural selection . That understanding was greatly extended in the 20th century through genetics and population ecology . Genetic variability arises from mutations and recombination , while organisms themselves are mobile, leading to geographical isolation and genetic drift with varying selection pressures . Genes can sometimes be exchanged between species by horizontal gene transfer ; new species can arise rapidly through hybridisation and polyploidy ; and species may become extinct for

5346-642: The Poles living in the Bieszczady area before 1947, but the area became much less populated than before 1947. In 2002, then president Aleksander Kwaśniewski expressed regret for this operation. In 1991, the UNESCO East Carpathian Biosphere Reserve was created that encapsulates a large part of the area and continues into Slovakia and Ukraine. It comprises the Bieszczady National Park (Poland), Poloniny National Park (Slovakia) and

5445-405: The abbreviation "sp." in the singular or "spp." (standing for species pluralis , Latin for "multiple species") in the plural in place of the specific name or epithet (e.g. Canis sp.). This commonly occurs when authors are confident that some individuals belong to a particular genus but are not sure to which exact species they belong, as is common in paleontology . Authors may also use "spp." as

5544-570: The amount of hybridisation is insufficient to completely mix their respective gene pools . A further development of the recognition concept is provided by the biosemiotic concept of species. In microbiology , genes can move freely even between distantly related bacteria, possibly extending to the whole bacterial domain. As a rule of thumb, microbiologists have assumed that members of Bacteria or Archaea with 16S ribosomal RNA gene sequences more similar than 97% to each other need to be checked by DNA–DNA hybridisation to decide if they belong to

5643-474: The biological species concept, "the several versions" of the phylogenetic species concept, and the idea that species are of the same kind as higher taxa are not suitable for biodiversity studies (with the intention of estimating the number of species accurately). They further suggested that the concept works for both asexual and sexually-reproducing species. A version of the concept is Kevin de Queiroz 's "General Lineage Concept of Species". An ecological species

5742-505: The biological species concept, a cladistic species does not rely on reproductive isolation – its criteria are independent of processes that are integral in other concepts. Therefore, it applies to asexual lineages. However, it does not always provide clear cut and intuitively satisfying boundaries between taxa, and may require multiple sources of evidence, such as more than one polymorphic locus, to give plausible results. An evolutionary species, suggested by George Gaylord Simpson in 1951,

5841-428: The boundaries between closely related species become unclear with hybridisation , in a species complex of hundreds of similar microspecies , and in a ring species . Also, among organisms that reproduce only asexually , the concept of a reproductive species breaks down, and each clone is potentially a microspecies. Although none of these are entirely satisfactory definitions, and while the concept of species may not be

5940-433: The concept of a chronospecies can be applied. During anagenesis (evolution, not necessarily involving branching), some palaeontologists seek to identify a sequence of species, each one derived from the phyletically extinct one before through continuous, slow and more or less uniform change. In such a time sequence, some palaeontologists assess how much change is required for a morphologically distinct form to be considered

6039-416: The concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. About 14% of these had been described by 2011. All species (except viruses ) are given a two-part name , called a "binomial". The first part of a binomial is the genus to which the species belongs. The second part

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6138-577: The contiguous distribution area) and the northwest of the Czech Republic (near Karlovy Vary , the northernmost known current natural presence of the species). Also found in a separate enclave south of Greater Caucasus along the Russian, Georgian and Turkish northeastern and eastern shores of the Black Sea. Two further enclaves include the first around Lake Urmia in northern Iran, and on the northern slopes of Mount Ararat in east Turkey, roughly halfway between

6237-435: The evidence to support hypotheses about evolutionarily divergent lineages that have maintained their hereditary integrity through time and space. Molecular markers may be used to determine diagnostic genetic differences in the nuclear or mitochondrial DNA of various species. For example, in a study done on fungi , studying the nucleotide characters using cladistic species produced the most accurate results in recognising

6336-425: The eye and connecting to the neck marks, and one short vertical stripe connecting the eye with the fourth to fifth upper labial scales. Adults are much more uniform, sometimes being olive-yellow, brownish-green, sometimes almost black. Often in adults, there may be a more or less regular pattern of white-edged dorsal scales appearing as white freckles all over the body up to moiré-like structures in places, enhancing

6435-537: The female's head with its jaw (Lotze 1975). 4 to 6 weeks after about 10 eggs are laid (extremes are from 2 to 20, with 5–11 on average) in a moist, warm spot where organic decomposition occurs, usually under hay piles, in rotting wood piles, heaps of manure or leaf mold, old tree stumps and similar places. Particularly in the northern parts of the range, preferred hatching grounds often are used by multiple females and are also shared with grass snakes . The eggs incubate for around 8 (6 to 10) weeks before hatching. Apart from

6534-476: The former and the Black Sea habitats. V.L. Laughlin hypothesized that parts of the species' geographical distribution may be the result of intentional placement and later release of these snakes by Romans from the temples of Asclepius , classical god of medicine, where they were important in the medical rituals and worship of the god. The previously recognised subspecies Zamenis longissimus romanus , found in southern Italy and Sicily, has been recently elevated to

6633-606: The medical professions as used in a number of variations today. The species, along with four-lined snakes , is carried in an annual religious procession in Cocullo in central Italy, which is of separate origin and was later made part of the Catholic calendar. Though the Aesculapian snake occupies a relatively broad range and is not endangered as a species, it is thought to be in general decline largely due to anthropic disturbances. The snake

6732-462: The more significant energy input of the latter into the reproductive cycle. Maximum weight for German populations has been 890 grams (1.96 lb) for males and 550 grams (1.21 lb) for females ( Böhme 1993; Gomille 2002). Other distinctions, as in many snakes, include in males a relatively longer tail to total body length and a wider tail base. Scale arrangement includes 23 dorsal scale rows at midbody (rarely 19 or 21), 211-250 ventral scales ,

6831-945: The north (up to about the latitude of Paris), the Spanish Pyrenees and the eastern side of the Spanish northern coast, Italy (except the south and Sicily), all of the Balkan peninsula down to Greece and Asia Minor and parts of Central and Eastern Europe up until about the 49th parallel in the eastern part of the range (Switzerland, Austria, South Moravia ( Podyjí /Thayatal in Austria) in the Czech Republic, Hungary, Slovakia, south Poland (mainly Bieszczady / Bukovec Mountains in Slovakia), Romania, south-west Ukraine). Further isolated populations have been identified in western Germany ( Schlangenbad , Odenwald , lower Salzach , plus one - near Passau - connected to

6930-478: The numerous fungi species of all the concepts studied. Versions of the phylogenetic species concept that emphasise monophyly or diagnosability may lead to splitting of existing species, for example in Bovidae , by recognising old subspecies as species, despite the fact that there are no reproductive barriers, and populations may intergrade morphologically. Others have called this approach taxonomic inflation , diluting

7029-585: The paper is accepted for publication. The type material is usually held in a permanent repository, often the research collection of a major museum or university, that allows independent verification and the means to compare specimens. Describers of new species are asked to choose names that, in the words of the International Code of Zoological Nomenclature , are "appropriate, compact, euphonious, memorable, and do not cause offence". Books and articles sometimes intentionally do not identify species fully, using

7128-674: The person who named the species, while the antonym sensu lato ("in the broad sense") denotes a wider usage, for instance including other subspecies. Other abbreviations such as "auct." ("author"), and qualifiers such as "non" ("not") may be used to further clarify the sense in which the specified authors delineated or described the species. Species are subject to change, whether by evolving into new species, exchanging genes with other species, merging with other species or by becoming extinct. The evolutionary process by which biological populations of sexually-reproducing organisms evolve to become distinct or reproductively isolated as species

7227-726: The population estimated at around 40. In 2020, a third population was confirmed in Britain, this one in Bridgend , Wales. This group has thrived for approximately 20 years. As of 2022, the Aesculapian snake is believed to be the only non-native species of snake in the United Kingdom to have established breeding populations. The Aesculapian snake prefers forested, warm but not hot, moderately humid but not wet, hilly or rocky habitats with proper insolation and varied, not sparse vegetation that provides sufficient variation in local microclimates, helping

7326-449: The protection through non-intervention of the species' core distribution centers, including targeted protection of potential hatching and hibernation places like old growth zones and fringe ecotones near woodland areas. A significant threat also are roads both in terms of new construction and rising traffic, with a risk of further fragmentation of populations and loss of genetic exchange. Species A species ( pl. : species)

7425-542: The range it has been reported to only use the canopy on a more substantial basis in largely uninhabited areas, such as the natural beech forests of the East Slovak and Ukrainian Carpathians , with similar characteristics. Minimum length of individuals entering the reproductive cycle has been reported at 85–100 cm, which corresponds to sexual maturity age of about 4–6 years. Breeding occurs annually after hibernation in spring, typically from mid-May to mid-June. In this time

7524-593: The recent taxonomic changes, there are currently four recognised phylogeographically traceable genetic lines in the species: the Western haplotype , Adriatic haplotype, the Danube haplotype and Eastern haplotype. The status of the Iranian enclave population remains unclear due to its specific morphological characteristics (smaller length, scale arrangement, darker underbelly), probably pending reclassification. The Aesculapian snake

7623-425: The record size being 225 cm (7.38 ft). Expected body mass in adult Aesculapian snakes is from 350 to 890 g (0.77 to 1.96 lb). It is dark, long, slender, and typically bronzy in colour, with smooth scales that give it a metallic sheen. Juveniles can easily be confused with juvenile grass snakes ( Natrix natrix ) and barred grass snakes ( Natrix helvetica ), because juvenile Aesculapians also have

7722-489: The region often have two or more name variants (unstable terminology), usually containing the word Beščady in combination with some other terms. Historically, the terms Bieszczady / Beščady / Beshchady have been used for hundreds of years to describe the mountains separating the old Kingdom of Hungary from Poland . A Latin language source of 1269 refers to them as " Beschad Alpes Poloniae " (translated as: Bieszczady Mountains of Poland ). The Polish folk etymology holds

7821-662: The reptile with thermoregulation . In most of their range they are typically found in relatively intact or fairly cultivated warmer temperate broadleaf forests including the more humid variety such as along river valleys and riverbeds (but not marshes) and forest steppes . Frequented locations include places such as forest clearings in succession, shrublands at the edges of forests and forest/field ecotones , woods interspersed with meadows etc. However, they generally do not avoid human presence, being often found in places such as gardens and sheds, and even prefer habitats such as old walls and stonewalls, derelict buildings and ruins that offer

7920-487: The result of misclassification leading to questions on whether there really are any ring species. The commonly used names for kinds of organisms are often ambiguous: "cat" could mean the domestic cat, Felis catus , or the cat family, Felidae . Another problem with common names is that they often vary from place to place, so that puma, cougar, catamount, panther, painter and mountain lion all mean Puma concolor in various parts of America, while "panther" may also mean

8019-516: The results of genetic analyses (it is closest genetically to the Carpathian populations). This likely applies also to the German populations. There are also fossils showing that they had UK residency during earlier interglacial periods but were driven south afterwards with subsequent glacials ; these repeated climate-caused contractions and extensions of range in Europe appear to have occurred multiple times over

8118-573: The ring. Ring species thus present a difficulty for any species concept that relies on reproductive isolation. However, ring species are at best rare. Proposed examples include the herring gull – lesser black-backed gull complex around the North pole, the Ensatina eschscholtzii group of 19 populations of salamanders in America, and the greenish warbler in Asia, but many so-called ring species have turned out to be

8217-555: The roofs of buildings. Observed optimum temperature for activity in German populations is 20–22 °C (68–72 °F) (Heems 1988) and they are rarely recorded below 16 °C (61 °F) or above 25 °C (77 °F), other observations for Ukrainian populations (Skarbek et Ščerban 1980) put minimum activity temperature from 19 °C (66 °F) and optimum to 21–26 °C (70–79 °F). Above around 27 °C (81 °F) they try to avoid exposure to direct sunlight and cease activity with more extreme heat. The snakes will exhibit

8316-508: The same species. This concept was narrowed in 2006 to a similarity of 98.7%. The average nucleotide identity (ANI) method quantifies genetic distance between entire genomes , using regions of about 10,000 base pairs . With enough data from genomes of one genus, algorithms can be used to categorize species, as for Pseudomonas avellanae in 2013, and for all sequenced bacteria and archaea since 2020. Observed ANI values among sequences appear to have an "ANI gap" at 85–95%, suggesting that

8415-529: The same species. When two species names are discovered to apply to the same species, the older species name is given priority and usually retained, and the newer name considered as a junior synonym, a process called synonymy . Dividing a taxon into multiple, often new, taxa is called splitting . Taxonomists are often referred to as "lumpers" or "splitters" by their colleagues, depending on their personal approach to recognising differences or commonalities between organisms. The circumscription of taxa, considered

8514-459: The shiny metallic appearance. Sometimes, especially when pale in colour, two darker longitudinal lines along the flanks can be visible. The belly is plain yellow to off-white, while the round iris has amber to ochre colouration. Melanistic , erythristic , and albinotic natural forms are known, as is a dark grey form. Although there is no noticeable sexual dimorphism in colouration, males grow significantly longer than females, presumably because of

8613-479: The snake is one of the longest over its range. The common name of the species — "Aesculape" in French and its equivalents in other languages — refers to the classical god of healing (Greek Asclepius and later Roman Aesculapius ) whose temples the snake was encouraged around. It is surmised that the typical depiction of the god with his snake-entwined staff features the species. Later from these, modern symbols developed of

8712-409: The snakes actively seek each other and mating begins. Rival males engage in ritual fights the aim of which is to pin down the opponent's head with one's own or coils of one's body; biting may occur but is not typical. The actual courtship takes the form of an elegant dance between the male and female, with anterior portions of the bodies raised in an S-shape and the tails entwined. The male may also grasp

8811-502: The species concept and making taxonomy unstable. Yet others defend this approach, considering "taxonomic inflation" pejorative and labelling the opposing view as "taxonomic conservatism"; claiming it is politically expedient to split species and recognise smaller populations at the species level, because this means they can more easily be included as endangered in the IUCN red list and can attract conservation legislation and funding. Unlike

8910-452: The species' area in the warmer Atlantic period (around 8000–5000 years ago) of Holocene reached as far north as Denmark. Three specimens were collected in Denmark between 1810 and 1863 on the southern part of Zealand , presumably from a relict and now extinct population. The current northwestern Czech population now is considered an autochthonous remnant of that maximum distribution based on

9009-962: The species. In the north their line of presence appears temperature-limited. Their main food source are rodents up to the size of rats (a 130 cm adult specimen has been reported to have overpowered a 200g rat) and other small mammals such as shrews and moles. They also eat birds as well as bird eggs and nestlings. They suffocate their prey by constriction, though harmless smaller mouthfuls may be eaten alive without constriction, or simply crushed on eating by jaws. Juveniles mainly eat lizards and arthropods, later small rodents. Other snakes and lizards are taken, but only found rarely in adult prey. Predators include badgers and other mustelids , foxes, wild boar (mainly by digging up and decimating hatches and newborns), hedgehogs, and various birds of prey (though there are reports of adults successfully standing their ground against feathered attackers). Juveniles may be eaten by smooth snakes and other reptilivorous snakes. Also

9108-420: The status of a separate new species, Zamenis lineatus (Italian Aesculapian snake). It is lighter in color, with a reddish-orange to glowing red iris. The populations previously classified as Elaphe longissima living in south-east Azerbaijan and northern Iranian Hyrcanian forests were reclassified by Nilson and Andrén in 1984 to Elaphe persica , now Zamenis persicus . According to fossil evidence,

9207-513: The term Bieszczady to have stemmed from the terms Bies and Czad (possibly from Chort ) along with the Polish plural y stem giving Bies + czady + y . Some folk stories connect the origin of the mountains to the demonic activity of the Biesy and Czady , while other folk stories tell of the mountains being populated with hordes of Biesy and Czady , hence the name. Another less probable possibility

9306-462: The term usually refers (in the narrower sense) to the Polish part of the Bieszczady region, while in the wider sense it can also refer to the entire region. In Slovakia, the Bieszczady region is known as Beščady , while the Slovak part of the region is called Bukovec Mountains (Slovak: Bukovské vrchy ). In Ukraine, the Bieszczady region is known as Beshchady (Ukrainian: Бещади ), while various parts of

9405-537: The wild. It is difficult to define a species in a way that applies to all organisms. The debate about species concepts is called the species problem. The problem was recognised even in 1859, when Darwin wrote in On the Origin of Species : I was much struck how entirely vague and arbitrary is the distinction between species and varieties. He went on to write: No one definition has satisfied all naturalists; yet every naturalist knows vaguely what he means when he speaks of

9504-716: The winter of 1914/1915. Up until 1947, about 75% of the population of the Polish part of the Bieszczadzkie Mountains was Boyko . The killing of the Polish General Karol Świerczewski in Jabłonki by the Ukrainian Insurgent Army in 1947 was the direct cause of the replacement of the Boykos, the so-called Operation Vistula . The area was mostly uninhabited afterward. New Poles settled in the Bieszczady, joining

9603-431: Was first described by Josephus Nicolaus Laurenti in 1768 as Natrix longissima , later it was also known as Coluber longissimus and for the most part of its history as Elaphe longissima . The current scientific name of the species based on revisions of the large genus Elaphe is Zamenis longissimus . Zamenis is from Greek ζαμενής "angry", "irritable", "fierce", longissimus comes from Latin and means "longest";

9702-752: Was part (all parts below the San ), Hungarians and West Slavs invaded the area. The region subsequently became part of the Great Moravian state. Upon the invasion of the Hungarian tribes into the heart of the Great Moravian Empire around 899, the Lendians of the area declared their allegiance to the Hungarians. The region then became a site of contention between Poland, Kievan Rus and Hungary starting in at least

9801-483: Was reported in 2010 along Regent's Canal , near the London Zoo , likely living on rats and mice, and thought to number a few dozen. Growth of this population may be limited due to the urban setting and potential scarcity of appropriate nesting sites. It is thought this colony has been present for years, living unseen: it is not harmful or invasive and is predicted to die out. Sightings were still being reported in 2023, with

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