Даревския құмдық кесірткелерінің туысы

Genus of lizards
Automatic taxobox
| image = Darevskia raddei Скальная Ящерица. jpg
| image caption = Darevskia raddei
| taxon = Darevskia
| authority = Arribas, 1999

In 1830, a professor at Kazan University, Eduard Friedrich Eversmann (1794 1860) made an expedition to the North Caucasus. As a result of which he described two new species: a meadow lizard, Lacerta praticola , and a rock lizard Lacerta saxicola At that time, European scientists did not recognize the independence of the species L. saxicola, considering it as part of the European L. muralis But at the beginning of the XX century between the two zoologists Lajos Méhelÿ (1862–1953) and George Albert Boulenger (1858–1937) there was a lengthy discussion about the taxonomic position of L. saxicola, which was resolved in favor of the former, and L. saxicola and subspecies were further considered separately from L. muralis. For several decades, scientists from different countries studied the monophyletic group of rock lizards independently, highlighting new subspecies, simplifying some taxa and describing new species. It was on this group of lizards that the phenomenon of parthenogenesis in amniotic vertebrates was first discovered by the Russian zoologist Ilya Sergeyevich Darevsky (1924 2009), who also made a significant contribution to understanding the ecology, systematics, and morphology of rock lizards. In 1997, the Spanish scientist Oscar J. Arribas named the genus of rock lizards Darevskia and designated the type species as D. saxicola.

Rock lizards are common in Abkhazia, Azerbaijan, Armenia, Georgia, Iran, Nagorno Karabakh, Russia (Adygea, Dagestan, Ingushetia, Kabardino Balkaria, Karachay Cherkessia, Krasnodar Territory, Republic of Crimea, North Ossetia Alania, Stavropol Territory and Chechnya), in Turkey and South Ossetia. It is worth noting that the boundaries of the range of some species are not reliably known, but the expected areas of their encounters coincide with the already indicated distribution sites for the whole genus

Rock lizards are found in various high altitude zones from above sea level and occupy a variety of landscapes: mountain steppe, forest steppe, mountain meadow, mountain forest, anthropogenic and coastal. By confinement to one or another habitat, they can be conditionally divided into several groups:

1) Lizards living in the forest, according to the occupied microreliefs, are divided into: adhering to rock outcrops (D. raddei, D. brauneri) and independent of them, able to live in habitats in which there are no rocks, using rodent burrows as shelters, deciduous litter, cavities in trees and bark (e. g. D. chlorogaster, D. armeniaca). 2) Inhabitants in areas of bedrock outcrops and clayey cliffs in alpine and subalpine meadows. As shelters, they often use rodent burrows, cavities between stones and cracks in the rocks. These habitats are adhered to by D. alpina and D. mixta, D. armeniaca and D. valentini. 3) Rock lizards of dry and moderately dry landscapes (alpine steppes) of rocks and their feet on slopes with dry loving shrubbery and grassy vegetation, road slopes. Such habitats have a large number of crevices and voids serving as shelters for lizards. Such species are found in such landscapes as: D. rudis, D. portschinski, D. daghestanica, D. raddei, D. saxicola. 4) Occupying anthropogenic habitats: an abandoned building, walls in cities, abandoned temples, monasteries, etc., where their number often exceeds that in natural habitats. For example, D. armeniaca, D. lindholmi, D. dahli. Rock lizards are found at heights of 0 – 3000 m above sea level. Zonal and geographical distribution is determined by the amount of precipitation, average annual temperature, duration of the adverse season, and exposure of the slope. For example, D. daghestanica on the southern slope of the Greater Caucasus Mountain Range (South Ossetia) is distributed at altitudes of above sea level, and on the northern slopes (Dagestan) at above sea level.

Rock lizards feed on various invertebrates with a body size from a few millimeters to : spiders, diptera, lepidoptera, hymenoptera, cockroaches, orthoptera, semi rigid winged, coleoptera, wood lice, worms, slugs, marine and freshwater amphipods, caddis flies, chironomids and sometimes parts of plants. Also, particular cases of cannibalism were recorded when adults ate juvenile individuals. Despite the diversity of the food supply, rock lizards can develop preferences for feeding on invertebrates of a certain group (for example, flying forms of ants), which is caused by seasonal changes in the availability or abundance of this type of prey. Even after a significant reduction in the density of invertebrates of this group, lizards continue to hunt for them for some time in the presence of more accessible food objects.

The seasonal activity of rock lizards is determined by temperature indicators. Therefore, species living at different heights differ in terms of exit from wintering shelters, mating period, laying of eggs, hatching of young individuals and time of leaving for wintering. Around the end of February until the end of May, exit from wintering shelters occurs, and the active period is from 6–7 months (in the mountains) and up to 9–10 months (in the valleys and on the seashore). During this period, mature individuals mate, and females lay eggs. Hibernation takes place from late September to mid November. The beginning and end of the daily activity of the lizard is determined by the lighting conditions within the individual area, and in some individuals it can start early in the morning, while individuals living on the slopes of the northern exposure or in deep forest valleys are active for several hours in the middle of the day [4]. After heating (basking), the body temperature of the lizard reaches about 30–34 °C (86–93 °F), and it begins a routine activity aimed at supporting the body. Late in the evening, when the heat subsides, the animals return to the basking places and stay there for some time, after which they go to their night shelters.

Rock lizards reach maturity in the second (females) and third (males) year of life with a total life expectancy of up to 13 years. Mating of some species of rock lizards occurs after the first molt, approximately 3–5 weeks after leaving wintering (D. brauneri), in others, immediately after leaving wintering shelter (D. valentini). Egg laying begins in the second half of June and lasts until early August. Clutch size is usually 2 to 7 eggs. The incubation period lasts approximately 55–65 days. Young animals with a snout to vent length (SVL) of about are born in late summer.

Separation of the genus Darevskia from the subfamily Lacertinae occurred approximately 12 16 million years ago, in the middle of the Miocene. Presumably, the ancestral form of the genus Darevskia penetrated the territory of the Western Caucasus in the Middle Miocene or in the Middle Pliocene, when there was a land connection between Asia Minor and the Balkans. The genus of rock lizards has 7 parthenogenetic species: D. armeniaca, D. bendimahiensis, D. dahli, D. rostombekovi, D. sapphirina, D. unisexualis and D. uzzelli, resulting from the hybridization of males and females of different bisexual species. Moreover, D. valentini and D. portschinskii always enter as paternal species, and D. mixta, D. nairensis, D. raddei always enter as maternal species. From the point of view of the classical concept of a species, homosexual taxa cannot be assigned a species status due to the lack of exchange of genetic material between individuals within the same population. However, on the basis of morphological and cytogenetic characters, they are assigned a species rank. The appearance of parthenogenetic species is usually associated with the last, Wurm glaciation. Parthenogenetic rock lizards appeared about 10 thousand years ago when, due to the formation of mountain glaciers, the habitats of the parent bisexual species were disturbed, which led to the overlap of their ranges and the hybridogenic formation of parthenogenetic individuals better adapted to the conditions of short summers and long winters. Due to the doubled reproduction rate and successful resettlement, same sex populations later began to exist independently of the parent species. Hybridization occurs in places where the ranges of parthenogenetic and bisexual species overlap, resulting in the appearance of triploid sterile females and a small number of males, with changes in the reproductive system (malfunctions in the formation of reproductive products, hermaphroditism). Nevertheless, presumably, these males are able to give offspring, which leads to the appearance of tetraploid hybrids. Sometimes males emerge from unfertilized eggs laid by parthenogenetic females. Like males of hybrid origin, they have reproductive disorders, which may not interfere with their offspring. A small amount of parthenogenetic female males emerging from clutches is explained by frequently occurring mutations incompatible with life. Despite the fact that as a result of parthenogenesis, individuals are born that receive hereditary material only from the mother's body, a small intraspecific genetic diversity has been revealed due to mutational processes, genetic instability and the appearance of same sex species as a result of repeated and independent crossing of parental species among themselves.