Types of Siberian frogs. Siberian frog - Rana amurensis Boul. Behavior and nutrition

Siberian frog ( Rana chensinensis) inhabits Siberia, North-Eastern Kazakhstan, Northern Kyrgyzstan, Far East and is found in Primorye, Amur region, Sakhalin, Shantar Islands.

In the west, the border of its distribution runs between 70 and 80 degrees east longitude. To the south it goes down to Central China, to the north it reaches the tundra.

To the east of the Urals along the forest and forest-steppe belt, it seems to replace the grass and sharp-faced frogs. Like the latter, it is found in steppes and semi-deserts.

In most of its range, the Siberian frog is attached to river floodplains, where it inhabits open lowland marshes and swampy lake shores. On Sakhalin it lives in floodplain meadows and swamps, including tundra ones. IN southern parts The habitat is kept only near water bodies.

Active in the evening hours, often active during the day. The basis of food is insects. Siberian frog leaves for the winter at the end of September - beginning of October. It overwinters in the thickets of swampy reservoirs in wells and on land near the water in pits with rotting vegetation, in soil crevices, and in rodent burrows.

The Siberian frog appears in spring in March - early April. Vital for seven to eight months a year. Soon after waking up it begins to spawn. Mating season lasts from two weeks to a month. Males occasionally make quiet sounds. Mating takes place underwater.

The female lays 1000-1800 eggs, colored dark brown. The diameter of the egg is 1.7-2.3 mm, the eggs - 5-7 millimeters. The spawning grounds are reservoirs in the floodplains of rivers, shallow, slightly swampy, slowly flowing springs. Eggs are usually laid when the water temperature is 18 degrees Celsius.

Tadpoles hatch after 6-10 days, reaching a length of 7-12 mm. Tadpoles, already leading an active lifestyle, are dark gray on top with small spots and specks of brown color. On the underside, the tadpoles are single-colored, gray, and their body is very transparent.

By the end of development, the length of tadpoles ranges from 37 to 60 mm. They feed on phyto- and zooplankton and detritus. Feed of plant origin makes up 20-25%. The length of newly metamorphosed fingerlings is 13-17 millimeters.

The young frogs emerge on land in the last days of May. Development takes from 25 to 60 days. Over the course of a month, the size of the fingerlings increases by 7-10 millimeters and by the end of summer their length reaches 33 millimeters.

Boulenger, 1886
(= Rana cruenta - Middendorf, 1853; Rana middendorffi Steenstrup, 1869; Rana muta johanseni Kastschenko, 1902; Rana temporaria - Nikolsky, 1918 (part.); Rana asiatica - Nikolsky, 1918 (part.); Rana amurensis amurensis - Nikolsky, 1918 (part.); Rana chensinensis - Terentyev and Chernov, 1949)

Appearance. frogs small and medium sizes; maximum body length 78 mm (smaller in Primorye than in Siberia). Head relatively narrow, although its width is greater than its length; the muzzle is elongated and pointed. The dorsal-lateral folds are thin, light, and form a bend towards the eardrum. Hind limbs(shins) are not long. If they are folded perpendicular to the axis of the body, then the ankle joints touch or slightly overlap each other. If the limb is extended along the body, the ankle joint reaches the eye. Swimming membrane well developed. Interior calcaneal tubercle small; its length ranges from 1/5 to 1/3, on average 1/4, of the length of the finger.

2 - articular tubercles, 3 - external calcaneal tubercle, 4 - internal calcaneal tubercle

Resonators are absent in males. Marriage callus semi-dismembered on the first finger.

Leather on the back and especially the sides it is covered with numerous small tubercles-grains. Brown on top colors different shades from light to dark, often carmine. Dark spots can merge in the form of strands. A characteristic light stripe runs along the middle of the back, often flanked by tubercles. Dark temporal spot available. Bottom painted in characteristic blood red color on a white or gray background, in the form of small or large spots, and sometimes covering almost the entire surface. In the south of Sakhalin, some individuals are greenish or grayish-yellow below. Red tones may also be visible on the sides, less often on the back. Very often the small grains are also colored red. There is no yellow-green spot where the sides and hips meet.

Spreading. Siberian-Far Eastern species. Its huge range covers almost all of Siberia and the Russian Far East, including Sakhalin, as well as northern Mongolia, northeastern China and Korea. In Siberia, to the west the border of the range reaches the Sverdlovsk region (about 64° E), to the north in Yakutia to 71° N. w.

Taxonomy of the species. Formally, the species consists of 2 subspecies. In the southwest of Korea there is a smaller Korean frog, Rana amurensis coreana Okada, 1927, which may be a separate species. The rest of the range is occupied by the nominate subspecies, Rana amurensis amurensis Boulenger, 1886. For a long time The taxonomy of the species (especially nomenclatural issues) was confused, and the Siberian frog was combined into one species with the Far Eastern and Central Asian frogs.

Belongs to group brown frogs(group Rana temporaria).

Habitat. Inhabits forest and forest-steppe areas, being clearly a lowland species. Not known above 500 m above sea level (1200 m in Mongolia). Prefers open, moist habitats and gravitates towards bodies of water. It is found in floodplains and valleys of rivers and lakes, on alas in Yakutia, in wetlands (mari, hummocks), wet reed-sedge and other meadows, among bushes, including on the sea coast. In damp places, frogs penetrate into forests, preferring sparse larch, alder-birch, and occasionally appearing in forests of other types. In the south of Sakhalin, they live in mixed-grass glades of broad-leaved forests, among low-growing bamboo thickets. Frogs can be found on the outskirts of towns and cities, in parks, agricultural lands (in hay meadows, vegetable gardens, field edges, etc.). Animals clearly avoid living on the slopes of the hills, in the depths of forest areas. Occasionally, frogs are found along the banks of slightly brackish water bodies.

Activity. Frogs, especially young ones, are active during the day, but more often come across twilight. On cold nights, activity shifts to daylight hours.

Reproduction. Frogs in spring appear in the second or third ten days of April in Primorye and in the south of Sakhalin, at the end of April - May in Transbaikalia, in the first ten days of May in Yakutia, when the weather is still very unstable. The air temperature at this time is 2-5°C and higher (lower at night). There may still be an ice crust and snow on the reservoirs. Characteristic breeding sites are swampy or flooded meadows, hummocks, puddles, ditches, pits, small oxbow rivers, ponds, small lakes, shallow areas of larger reservoirs. On Sakhalin, frogs also use semi-flowing water bodies and desalinated coastal lakes of the lagoon type (sometimes with brackish water) as spawning grounds. Some bodies of water have a sandy bottom or a large layer of silt, often with sparse or no vegetation. The Siberian frog often breeds in the same bodies of water as the Siberian salamander.

The first to come to water bodies are males, who hide under the shore or in thickets of grass. Females arrive after 2-5 days. The voice of males is quiet, there are no loud concerts. Pairing takes 4-6 hours and occurs on the surface of the water or underwater at the bottom of the reservoir. The female lays 270-4040 eggs at a depth of up to 30 cm (in Mongolia much deeper, at least 40 cm), usually attaching masonry To aquatic plants. After swelling, the masonry floats.

The diameter of the egg is 6-7 mm, the egg is 1.6-2.1 mm. Spawning lasts for 2-4 weeks in the Far East, and up to 2 months in Transbaikalia. Very often, caviar dies due to drying out of reservoirs. Early clutches (up to 70-80%) die from frost.

Embryonic development lasts 7-16 days, larval from a month to 84 days. In the south of Sakhalin, the entire subject-morphosis period is 73-104 days. Tadpoles after hatching they are about 4-8 mm long. Before metamorphosis, the denticles on the oral disc are located in 3 rows above and below the beak. Fingerlings appear in July - early August with a body length of 12 mm or more. The emergence of fingerlings from reservoirs takes almost a whole month.

Sexual maturity occurs at the age of three years with a body length of 41-44 mm. The sex ratio is approximately equal. Maximum life expectancy in nature for at least 9 years.

Nutrition. Frogs eat mainly terrestrial invertebrates: insects (beetles, butterfly caterpillars, orthoptera, dipterans, etc.), as well as spiders, earthworms, and occasionally aquatic mollusks. During the breeding season they hardly feed. Tadpoles can eat the corpses of their fellows.

On frogs hunt some birds. Leeches attack egg laying; tadpoles are exterminated by the larvae of dragonflies, caddisflies and swimming beetles.

Wintering. Frogs leave for the winter at the end of September - beginning of November, young ones later than adults. They migrate to wintering areas at a distance of up to 3 km. They overwinter in ponds with stagnant water, at the bottom of wells. During the killings, a large number of individuals die. In the south of Sakhalin, the wintering period is 156-186 days.

Abundance and conservation status. The Siberian frog is a numerous species that lives in many nature reserves. There is no threat to the existence of the species. The species is not included in the Red Books of the USSR and Russia.

Similar species. It differs from the Far Eastern and sharp-faced frogs, with which it coexists in the Far East or Siberia, in the graininess of the skin on the sides, the absence of resonators, color pattern, smaller internal calcaneal tubercle and other characteristics. It is isolated geographically from other brown frogs (grass frogs, snapping frogs, Asia Minor and Central Asian frogs). It differs from the black-spotted frog in body color, small calcaneal tubercle and the absence of resonators.

At the Ecosystem Ecological Center you can purchase color identification table " Amphibians and reptiles of central Russia"and a computer identification of amphibians (amphibians) of Russia, as well as others teaching materials By aquatic fauna and flora(see below).

The range of the Siberian frog reaches the Arctic Circle and covers the region of the Pole of Cold in Yakutia, where winter temperatures often drop below -40 °C. Although the resistance of the species to freezing has not yet been thoroughly studied, it, along with Siberian salamander, probably the most cold-resistant among the amphibians of Eurasia.

The huge range of the Siberian frog covers almost all of Siberia and the Far East, including Sakhalin, as well as Northern Mongolia, northeast and Korea. In the west, the range border reaches Sverdlovsk region(about 64° east longitude), in the north in Yakutia - up to 71° northern latitude Several populations are known in the Arctic Circle. The species lives on some islands in the sea, rivers and lakes. It rises up to 500 m into the mountains.

CLOSE TO WATER

The Siberian frog is found in coniferous, deciduous and mixed forests, along river valleys it penetrates into the forest-steppe and forest-tundra, preferring floodplain forests and lowland swamps, wet meadows, floodplains of rivers and lakes. As a rule, it does not move away from the banks of water bodies, where it hides in case of danger. Wintering of Siberian frogs lasts from September-October to April-May and usually takes place at the bottom of non-freezing reservoirs: in oxbow lakes, ponds, holes at the bottom of channels at a depth of 1-2 m, where accumulations of up to 2000 individuals are formed. Less commonly, these amphibians overwinter on land: in the forest floor, in moss or under tree roots at a depth of 20-30 centimeters, up to 60 individuals together.

QUIET SOLO AND LOUD CHORUS

In the spring, frogs appear on the surface after wintering, when the weather is still very unstable and there is still ice on the reservoirs. They are looking for a suitable place for breeding: a pond, a water meadow, a ditch, a puddle, a hole or a small oxbow lake. Sometimes spawning occurs in semi-flowing reservoirs and coastal lagoons with slightly brackish water. The first to arrive here are the males, who can be distinguished by the dark nuptial callus on the first toe of the forelimbs. Their friends come over a few days later. Unlike most other species of frogs, the Siberian frog does not have resonators, and therefore mating calls are low and quiet. However, the general chorus can be heard at a distance of up to 100 meters.

Mating of the Siberian frog takes 4-6 hours and occurs on the surface of the water or underwater at the bottom of the reservoir. The female lays from 270 to 4000 eggs in one or two clumps at a depth of up to 40 cm, usually attaching the clutch to aquatic plants.

After swelling it floats up. The density of masonry can reach 40 pieces per 1 square. m. The diameter of the egg with shells is 6-7 millimeters, the egg is 1.6-2.1 millimeters.

Spawning lasts from 2 weeks to 2 months.

THEY GROW FASTER IN WARM TIMES

Depending on the water temperature, larvae 7-8 mm long emerge after 3 or 20 days. They are translucent, dark gray, with small brown spots. From 25 to 84 days, tadpoles actively swim, eating microscopic algae, detritus and zooplankton, and grow to 34-45 mm. However, after metamorphosis in July - early August, having turned into frogs, individuals become 2-3 times smaller. Their diet also changes. Now they eat adult frog food: insects and their larvae, spiders, worms, mollusks, woodlice and aquatic invertebrates. In the second year of life, red spots appear on the belly of the young, and at three years, with a body length of over 40 mm, the frogs can continue the race.

VERY DURABLE

Many predators feed on frogs: fish (pike, catfish, taimen, lenok), amphibians (lake frog and black-spotted frog), snakes (common and tiger snake, patterned snake, common viper and Ussuri copperhead), mammals (otter, badger, weasel, raccoon dog and muskrat), birds of prey and corvids (harriers, spotted eagles, kites, herons). Up to 80% of clutches can die from frost or from drying out of temporary reservoirs. Despite this, there are enough frogs for everyone and the state of the species does not cause concern.

The creation of hydroelectric power stations in the area has a much stronger effect on population numbers. large rivers Siberia, drainage of reservoirs, death on highways, mass catching for the purposes of education and medicine, illegal collection and export for the purposes of Chinese traditional medicine. But the Siberian frog can still cope with these loads, only on the periphery of its range it is found sporadically, it is rare and is included in the Red Books of nine regions of Russia.

INTERESTING FACTS

For a long time, all representatives of the genus of brown frogs living in Siberia and the Far East were classified by zoologists as a widespread species - the grass frog (Rana temporaria). And only in 1886, the famous European herpetologist G. A. Boulanger described a new independent species from the Amur River valley - the Siberian frog. From the sharp-faced and Far Eastern frogs, also belonging to the genus Rana, the Siberian differs in bright red spots on the belly and the absence of resonators in males, and from the lake and black-spotted ones it also has dark temporal spots.

A BRIEF DESCRIPTION OF

Class: amphibians.
Order: tailless amphibians.
Family: true frogs.
Genus: brown frogs.
Species: Siberian, or Amur, frog.
Latin name: Rana amurensis.
Size: body length - up to 8.5 centimeters.
Color: olive-gray or brown above with dark spots and red specks, a narrow light stripe in the middle of the back, belly white or grayish with bright red merging spots.
Life expectancy of the Siberian frog: up to 11 years.

In the genus brown frogs there is such a species as the Siberian frog. Its habitat is quite extensive. It covers Western and Eastern Siberia, the Far East, Northeast China, the northeastern regions of Mongolia, the north of the Korean Peninsula, Sakhalin. Representatives of the species live in mixed, deciduous, coniferous forests, found in the tundra and steppes.

Preference is given to damp places. These can be swamps, banks of rivers, lakes, periodically flooded meadows with dense vegetation and forest debris. These frogs do not live in forest thickets. But the presence of a reservoir is a prerequisite.

Description

These amphibians are small in size. Body length varies from 2 to 2.5 cm. The skin is smooth. Top part The body is light brown and covered with small dark spots. Stomach white with a yellowish tint and large red spots. Often red spots alternate with dark spots. Red patterns appear on the abdomen in the 2nd and sometimes in the 3rd year of life. Males have nuptial calluses on their first toes. dark color. There are membranes between the fingers, the pupils are located horizontally.

Reproduction and lifespan

In warm areas (Korea), the breeding season begins at the end of February, but mainly takes place in March - April. In the cold north it can last until July. The Siberian frog breeds in shallow reservoirs with stagnant water. This species does not have characteristic mating calls.

The female lays eggs in clumps. In one such lump or bag there are 30-60 eggs. Metamorphosis ends in the month of August. IN wildlife Representatives of this species live 3-5 years. Moreover, life expectancy directly depends on the specific region of residence.

Behavior and nutrition

Hibernation for these amphibians begins in September–November, depending on the region, and ends in March–May. Siberian frogs overwinter at the bottom of reservoirs. These can be ponds, rivers, lakes. Several thousand individuals gather in one place and wait out the winter cold. In warm southern regions, hibernation can also be on the ground.

The diet of tadpoles and frogs differs. The first ones eat algae growing on seabed, as well as aquatic invertebrates. Young frogs eat terrestrial insects and aquatic arthropods. Adults feed mainly on terrestrial invertebrates.

Conservation status

This species is not endangered according to the IUCN. The population density is quite high. At the same time, these amphibians live in dense but isolated groups. If these groups are distributed evenly throughout their habitat, their numbers will be low. The main threat is loss natural environment a habitat. Representatives of the species are very sensitive to any natural disturbances and die quickly.

(lat. Rana amurensis) - a species of the family of true frogs ( Ranidae).

Description

The back is grayish or gray-brown with small dark spots. The belly is white or white-yellowish with large, irregular, partially confluent blood-red spots. Red spots may alternate with dark spots, and a red pattern on the abdomen begins to form around the second year of life. Males differ from females by the presence of a dark nuptial callus on the first toe. The head is moderately sharp. The tibia is 1.75-2.4 times shorter than the body. The fingers are connected by membranes. The pupil is horizontal. The back of the tongue is free and forked.

Spreading

This frog lives in western and eastern Siberia, Far East Russia, Korea, northern and central Mongolia and northeastern China. This is one of the most common amphibians of the Palearctic. It is found in coniferous, mixed and deciduous forests, penetrates the tundra and forest-steppe zone. This occurs most often in open, damp places, such as wet meadows, swamps, overgrown banks of lakes, rivers, and open areas in forests with abundant vegetation and woody debris. The connection with reservoirs (overgrown river valleys with ponds and lakes) is especially characteristic in the southern (forest-steppe and steppe) and northern regions. In the south of Primorsky Krai, this species avoids dense forests and is found mainly in damp meadows with deciduous trees or bushes in river valleys.

Lifestyle

The population density over a large area reaches several hundred and thousand individuals per hectare. At the same time, on the northernmost and most southern regions throughout its range, the species forms dense but small groups in suitable locations, in which case the total abundance should be considered low. Hibernation occurs from early September - early November (usually October), in March - early June (usually April-May), depending on latitude. The frog overwinters in holes at the bottom of rivers and lakes, as well as in wells, usually in groups of up to several thousand individuals. Ground hibernation is more typical for southern regions. The maximum age is defined as 5-11 years in various regions.

Nutrition

Tadpoles eat mainly algae growing on underwater substrates, as well as higher plants, detritus and small aquatic invertebrates. Young frogs eat mainly terrestrial insects, sometimes aquatic arthropods. Adult frogs consume mainly terrestrial invertebrates and sometimes aquatic animals. The latter are especially important in the northern part of the frog's range.

Reproduction

The breeding season occurs from March-April, and in cold northern regions it can last until the first half of July. Reproduction occurs in small lakes, ponds, large puddles and swamps with standing water. Mating cries absent - the species belongs to the group of “mute” brown frogs. The clutch contains 250-4000 eggs, laid in one or two clumps. Metamorphosis occurs in June-August.