V E R T E B R A T A H U N G A R S C A M USE I H I S T O R t C O - N A T U R A L I S H U N G A R I C I

Tom. VIII. 1966. Fosc. 1-2.

The Herpetofauna off the Fehértó (Lake Fehér) near Kardoskúty Hungary

By M. Marián Móra F. Museum, Szeged

Until recently, no systematic assay of the herpetofauna of our alkali field had been made. Aside of the fact that the zoogeographical knowledge of the country were incomplete without the exploration of the herpetofauna of the alkali plains,the theme in itself raises a number of most interest-ing biological and ecological problems. Such too, which could be clearly and definitely answered, only by a thorough and comparative analysis of the faunas of the different types of natron waters. Since 1962, a research team, specially sponsored by the Hungarian Academy of Sciences, investigates regularly the life forms of the alkali waters. The present paper is one of the results of this project.

The lake called Fehértó is a temporary body of alkali water, formed on solonchak soil, 3 km long, and 11-12 km south of Orosháza. The water is strongly basic (pH 8.2). The highest water level attains lm; the supply depends on ground water. Evaporation is fairly big, an annual 700 mm at yearly average of 600 mm precipitation. Annual mean temperature: 10.6°C; summer mean temperature:22-23°C; winter mean temper-ature: -2 - -3°C (ANDÓ, 1966).

In the Fehértó, of a highly fluctuating water level and of extreme weather conditions, as well as in its neighbour-

hood, environmental conditions and concurrently also the possibilities of animal life are also liable to extreme changes within a relatively short space of time. The alkali „lake" or marsh turns, within the lapse of a single season, into a dusty, alkali, semi-desert. This also effects the evolvement of the number of amphibian and reptile species.

Let us first examine the species living in the several habitats. In delimiting the main biotopes,I follow the plant associations as defined by GY. BODROGKÖZI (1966).

In the open water, reptiles and amphibians occur only transitionally.

In the alkali marsh (Bolboschoenetum chenopodium bot-ryoides), the representatives of the two animal classes occur in the greatest numbers, especially in the spring and the beginning of summer, when the majority of the amphibians congregate for the laying of the eggs.

Of the Urodela, the great water newt (Triturus c. cris-tatus LAUR.) was found to occur until the middle of summer in the alkali marsh. Subsequent to the evaporation of the water, the animal retreats into the mud of the bottom of the lake or t>.e cracks of the coast.

The far-sounding mating voice of the green toad (Bufo v. viridis LAUR. ) can be heard already in the first days of April.

At the middle of May, its larvae swarm by the thousands in the coastal zone. The 1'ew inches or less of water warms up easily, and the algal crust covering the dense aquatic vegetation offers ample food for the tadpoles. Their deve-lopment and transformation proceed at the normal pace. At the beginning of July, the young, lunged forms jump around by the hundreds on the already waterless but still wet and muddy bottom of the marsh and the reedy patches. By the middle of summer,they leave the desiccated area and withdraw to the vicinity of the homesteads and the cultivated fields. This culturefollowing species tides over,by the very help of

man,the most difficult phase of the year,the summer drought.

Generally, the length of the captured specimens is 55-69 m™

only slightly below the measurements of green toad specimens

originating from other localities of the Great Plains.

The bombinator (Bombina bombinaL.) occurs in the great-

est number in the alkali marsh. A smaller amount inhabits

also the reeds. The species is less sensitive against the

pollution of the water, it can be found also in waterholes

defiled by dung. In contrast with the green toad, it is

strictly bound to water, be it but a retting-pit.

Interestingly, the mating and egg-laying of the bombi-

nator is rather protracted in the alkali area of Kardoskut.

Though mating commences already at the beginning of April,

single females heavy with eggs can yet be found at the end

of May. On 27 May, 1964, I found egg-filled females among

bombinator larvae of different phases of development.

The general length of the collected specimens lies bet-

ween 32-36 mm, rather behind the size of our home Bombina

bombina exemplars.

I also succeeded to find also the green-coloured va-

riety of the bombinator (Bombina bombina 1. var. viridis MA-

RIÁK). A specimen each was captured on the northern shores,

and in a well on the southern side, of the lake. Thus the

Fehértó near Kardoskut is the easternmost known locality of

the fine subspecies described from the reaches of the Tisza

(MARIÁN, 1959).

The most interesting frog species occurring in the soda

marsh in the spring is the spade-foot (Pelobates f. fuscus

LAÏÏR.). Its grunting voice, calling its mate, can be heard

from under the water already during April. After the laying

of the eggs, the frog leaves the water and assumes habits

similar to those of the green toad on the dry land.

The enormous tadpoles can be found in masses also

in the water of the hollows near the lake, and in nawy-

pits.

Of the amphibians inhabiting the waters of the reeds (Bolboschoenetum phragmitetosum), the most frequent is the marsh-frog (Rana ridlbunda PAIL.). Though this species lives in every aquatic habitat of the lake, it still prefers best the water patches between the reedy stands and the coastal zone covered with vegetation.

This is the biggest-sized frog species of the alkali plains. The general size of the specimens collected in the Fehértó is 60-69 mm.

The tree-frog (Hyla a. arborea L. ) also inhabits the reeds and the soda marshes. Owing to its protective color-ation, it is seldom observable, hence the populations seem to be small than they actually are.

The samll number of grass snakes (flatrix n. natrix L.) inhabit the grassy areas adjacent to the shores (Puccinelli-etosum), and the coastal zone itself. The frog and toad fau-r nas of the lake could nourish a considerably higher number of snakes than the observed one. However, the bare, tree- and bushless shores hardly offer suitable retreats and shelters for the species,thus being strongly decimated by its natural enemies. (After the evaporation of the water of the lake, the situation becomes the reverse: the snake can then find excellent hiding places in the reeds, but by then the number of amphibians serving for its food have already considerably decreased.)

The sand-lizard (Lacerta a. avilis L. ) lives on the grassy shores and the soda fields. A small population occurs along the southern shore of the lake.

A characterization of the herpetofauna

Six amphibian species (Triturus c. eristatus LATJR., Bom-bina bomb ina L., Pelobates f. fuscus LAUR., Bufo v. viridis LAUR., Hyla a. arborea L., Rana rldibunda PALL.) and one sub-species (Bomb ina bomb ina L. var. viridis MARliK) have been

found in and the nearer neighbourhood of the Fehértó at Kar-doskut. Therefore only one-third of the 15 home amphibian species inhabits this area. Of the six home amphibian families, it is merely the Salamandridae which is not re-presented here. Triturus v. vulgaris L., also belonging to this family, will probably be found in the research area (I have found it on the alkali flats near Pusztaszer).

Two reptile species (Lacerta a. agilis L., and Natrix n. natrix L.) were successfully shown, only a fragment of the 15 home reptilian species inhabiting Hungary. Two of the five home reptile families are thereby represented. The oc-currence of representatives of the families Anguidae and Sclncldae are not probable, whereas Emys orbicularis L., belonging to the family Emydidae, may yet be found to occur. ( I have demonstrated the species from the alkali lake of Kunfehértó.)

According to MÉHELY, the frog species form, owing to identical requirements as to habitats, coexistent species groups, following a given „leading species" (KEHELY, 1 9 0 1 ) . The leading species of the species group of the plains, as established by MÉHELYi, is Rana arvalis, accompanied by Bom-bina bombina, Pelobates fuscus, Rana ridibunda, and Bufo vi-ridis.

The assumption seems to be valid also for the frog spe-cies of the soda plains at Kardoskut with the difference, however, that the leading species, Rana arvalis, has not yet been found. Its occurrence seems probable on the basis of the above consideration. (I found the species in the alkali marsh of Kunfehértó.)

Owing to the rate of its numbers, Rana ridibunda is the dominant species among the ones inhabiting the research area.

The species are all widely distributed, hilly to flat-land species (eurytop taxa). They are therefore not natro-philous, but of a high ecological valency. In semi-desert

conditions, water is the most important environmental factor which makes the settling of the above species possible, or rather the survival of the specific populations. Even of the eurytop species, only some few can adapt themselves to such unfavourable conditions. This also explains the small number of the species. (The smaller size, as related to that occurring in plain areas of other characteristics, de-monstrable in some of the species also imply that conditions are not quite optimal for even those which live here.)

The individual numbers of the (aquatic forms of the) few amphibians inhabiting the research area are rather high. According to I . K I S S (1959),with respect to the phytoplankton of the Kardoskut lake, and as put forward by J.MEGYERI (1959), concerning the mesozooplankton of the alkali waters, the soda flats are characterized less by the high number of species than by the great number of individuals. Inte-restingly, this statement holds also for the amphibians, but only for the larval stage and the younger lunged form res-pectively, As soon as the amphibious Bpecies break away from the protective environment of the water, they come under extreme ecological effects. Pood supply decreases, since the sparse plant cover of the dry land fails to offer an abun-dance of Insect food. The number of predators increases. However, the decrease of the individual numbers can in es-sentials be ascribed to the summer drought, destroying tens of thousands of the young frog generation.

Progs and toads, being Poikilothermie animals, endure hunger rather well. However, their organism can hardly take measures against drying out. Members of the genus Rana and the family Discoglossidae are especially sensitive to this. In the survival of the amphibious fauna, the nawy holes, ditches j, abandoned wells around the lake play a decisive role.Bombinators and lake frogs,retreated to these shelters, obtain but a paucity of food there, but they can still weather drought rather well. (On 3 July, 1962, I observed

even belatedly mating bombinators in an abandoned well.) During the summer drought, the main shelters of the am-

phibian fauna are afforded by the deep cracks of the ground in the bottom of the lake and the coastal zone. They spend this dangerous period here in a sleep-like state (HEUSSER, 1961). However, as soon as the suboptimal environmental con-ditions tend to become better, owing to, for instance, the elevation of the ground water level, they immediately resume their activity. This was corroborated by my observation on 17 September, 1962. After two months of severe drought, the alkali flat was drenched In a deluge of rain. No frog was visible for days. After the storm, the bombinators appeared in a number of sites In spite of the late evening hours.

If the drying out of the waters coincides with still the larval stage of the species,they vill inexorably perish. This holds especially for Bombina bombina, not selective with respect to the site of egg-laying and frequently depo-siting its clusters of eggs even in very shallow waters. These of course will soon evaporate and the eggs die.

Difficulties of hibernation also contribute to the de-crease of individual numbers. The shallow autumnal waters of the lake will freeze to its bootm in cold winters. Specimens which were unable to retreat to deep enough nrud layers will also freeze. Ditches, pits, abandoned wells with deep water again play an important role.

Individual numbers are further decreased by indirect anthropogenous effects, exerted on the herpetofauna by the inhibitants of farms around the lake: the great number of domestic fowl constantly decimates the amphibian and reptile populations.

The apparent technophily (HEUSSER, 1961), evolving in certain amphibian species,is also connected with the anthro-pogenous effects .Bombinators and lake-Inhabiting frogs name-ly use for ovipositing-sites broken vessels and other domes-tic implements thrown into the water as though they were

aquatic plants or mud islands. They hang their egg-strands on stakes driven into the water, and also on wicker hedges, as if they were reed-stems or reed stumps.

Under technophily, we mean the active search for human artifacts. However, the above species do not actively search for the objects mentioned during their spawning, but only make use of them when finding those in their spawning sites. Hence this is only an apparent technophily.

The green toad is a better case in point, because this species actually visits human artifacts to search for hiding places and to feed on insects thriving in human environ-ments .

In the material and energy turnover of the area, herpe-tofauna again playes an important role, especially as far as the abundance of the amphibious larvae are concerned. They constitute a significant portion of the food of a great number of aquatic birds nidifying or feeding on the lake.

From the point of view of agriculture, no member of the herpetofauna is injurious. Indeed, owing to their entomopha-gous habits, they are definitely useful. It is merely the grass snake which might be accused of causing some damages, the destruction of the frogs. However, owing to the small number of its population, the damages - -9 negligible.

Summary

In the course of investigations in the years 1962-1965, I have established the presence of 6 amphibian species and 1 subspecies, as well as 2 reptile species, in the Fehértó near Kardoskut. They are all eurytop species tolerating the envi-ronmental conditions of the alkali plains. However, they are not natrophilous. Small specific and high individual numbers are characteristic of amphibians inhabiting the soda lake and its nevironment. The gravest danger of the herpetofauna lies in desiccation against which they protect themselves

by a sleep-like state. Anthropogeneous effects strongly de-cimates the amphibian and reptile stocks. An apparent techo-phily can be observed. The herpetofauna plays an important role in the material and energy turnover of the lake. All observed amphibians and reptiles, with the sxception of a neutral species, are useful from an agricultural point of view.

A Kardoskúti Fehértó herpetofaunaja

Irta: Morion Miklós Móra Ferenc Múzeum, Szeged

Szerző a Magyar Tudományos Akadémia által irányított szikeskutató program keretében 1962-1965-ig vizsgálta az Orosháza közelében, szoloncsák talajon fekvő, szélsőségesen kontinentális éghajlatú Kardoskúti Fehértó herpetofaunáját«

A különböző biotópokban 6 amphibia fajt (Triturus c. eristatus LAUR., Bombina bomblna L., Pelobates f. fuscus LAUR., Bufo v. viridis LAÜR., Hyla a. arborea L., Rana ridi-bunda PAIL.), egy fajváltozatot (Bombina bomblna Lc var. vi-ridis MARIÁK) és két reptilia fajt (Lacerta a.agilis L.,Nat-rix n. natrix L. ) talált. A kétéltűek domináns faja a Rana ridibunda PAH.

A fajok számát a szélsőséges környezeti adottságok ma-gyarázzák meg, amelyekhez csak kevés faj tud alkalmazkodni. Ezek sem natrophil tulajdonságú, hanem széles ökológiai va-lenciáju eurytop fajok, amelyek jól tűrik az olykor félsiva-tagi környezetet. A szikesekre jellemző a kis fajszámmal je-lenlévő amphibiák vizialakjainak (lárváinak) nagy egyedszá-ma. Az itt élő fajok egyedszámát legjobban csöökenti az a tény, hogy a tó vize nyáron teljesen elpárolog, télen fené-kig befagy. Mindkét esetben a tó közvetlen környékén talál-

ható mélyebb vízü árkok, gödrök, kutak mentik át a herpeto-fauna tagjait.

Az anyag- és energiaforgalomban a herpetofaunának je-lentős szereke van. Elsősorban emlithetők itt a különböző kétéltű faj ok nagy mennyiségben jelenlévő lárvái, melyek a visimadarak eledelének egy részét teszik ki.

A meg' igyelt kétéltűek és hüllők - a vizisikló kivéte-lével - a mezőgazdaságra hasznosak.

References - Irodalom

1. NADÓ, M.i A Kardoskuti Fehértó természeti földrajzi viszonyai (1966. Kézirat). - 2. ARANY, S.: A szikes talaj és javitása (Budapest, 1956, pp.408). - 3. ÁBRAHÁM, A.: Teen-dőink az Alföld állattani feldolgozása terén (Az Alföldi Tu-dományos Intézet 1944-45. Évkönyve, 1945, p.273-284). - 4. BODROGKÖZI, GY.: Á Kardoskuti Fehértó hal of il makrovegetá-ciója (1966. Kézirat). - 5- DADAY, J.: Adatok az alföldi szi-kes vizek mikro faunájának ismeretéhez (Mat.és Termtud. Ért. ,12, 1956,p. 10-43). - 6.D0NÁSZY,E.: AZ alföldi szikes tavak limnoló-giai kutatása (Hidrológiai Közlöny, 36, 2, 1956, p.129). -7. DUDICH, E.: A magyar állatvilág kutatásának megszervezése (Állattani Közlemények, 25, 1928, p.1-15). - 8. DUDICH, E.: A magyar zoológia ötéves terve (M.T.A. Biol. és Agrártud. Oszt. Közleményei, III, 1957, p.425-445). - 9. FEJÉRVÁRY-NÉ, LÁNG, A.M.: Beiträge und Berichtigungen zum Amphibien-und Reptilien-Teil des ungarischen Faunenkataloges (Fragm. Faun.Hung., 6, 2-3, 1943, p.42-38)- - 10. HEUSSER, H.: Die Bedeutung der äusseren Situation in Verhalten einiger Amphi-bienarten (Revue Suisse de Zoologie, 68, 1, 1961,p.24-25). -

11. KISS, I.: A Kardoskut-Pusztaközponti Fehértó mikrovege-

tációjja (Szegedi Pedagógiai F