Mara, Gyöngyvér

English

The author tries to identify the major threats for amphibian and reptile species in the Transylvanian rivers' basins. The herpetological investigations were performed during summertime in the hydrographic basins of Cri?ul Negru, Some? and Olt rivers, in the period 1997-1999. Two monitoring methods were used, occasional findings and information from local people. The most important factor in the dcclinc of herpetofauna from Transylvanian river's basins seems to be the loss of natural habitats. But the author considers that it is the time for quantitative field research, for a better study of herpetofauna conservation status. Finally, a few monitoring methods are proposed

Mara Gyöngyvér

University of Szeged

T I S C 1 A m o n o g r a p h s e r i e s ( 2 0 0 2 ) . 6 . 1 9 9 - 2 0 4 MAJOR THREATS FOR AMPHIBIAN AND REPTILES SPECIES IN THE TRANSYLVANIAN RIVERS' BASINS. RECOMMENDED MONITORING METHODS Mara Gyöngyvér Abstract The author tries to identify the major threats for amphibian and reptile species in the Transylvanian rivers' basins. The herpetological investigations were performed during summertime in the hydrographic basins of Cri?ul Negru, Some? and Olt rivers, in the period 1997-1999. Two monitoring methods were used, occasional findings and information from local people. The most important factor in the dcclinc of herpetofauna from Transylvanian river's basins seems to be the loss of natural habitats. But the author considers that it is the time for quantitative field research, for a better study of herpetofauna conservation status. Finally, a few monitoring methods are proposed. Keywords: Transylvanian rivers, reptile, monitoring methods. Introduction The loss of amphibian and reptiles species is a worldwidely well-known phenomenon. The freshwater organisms, as well as the amphibians, seem to disappear faster than other vertebrate classes (Griffiths & Beebee, 1992). Local and global changcs in environmental factors appear to contribute to the decline of amphibians, such as: global climatc change, UV radiation, intensive agriculture (use of pesticides), infections (viruses, fungi, parasites), habitat destruction, water pollution, introduction of other species, introduction of fish (managing fishponds). However, it is becoming clear that not all the spccics arc declining and that not one 'global' factor, but various complexes of factors are responsible for the decline in different parts of the world (Vos & Chardin, 1998). In Romania the national Nature Conservation Law (462/2001) and the Bern Convention (International Convention on the Conservation of European Wildlife) protect the amphibians and reptiles. Unfortunately, in spite of legislation numerous habitats of herpetological importance are threatened or even destroyed. The wetlands arc among the most threatened ones. The reduction of these habitats is a worldwide 199 problem, it causes habitat fragmentation and significantly reduces the population's viability. Material and methods The herpetological investigations were performed during summertime in the hydrographic basins of Cri$ul Negru. Some$ and Olt rivers, in the period 1997-1999. The distribution of amphibian and reptile species is better and better investigated in Transylvania (Ghira et al. in press), but we have a significant knowledge deficit regarding population fluctuations. Amphibians are characterized by considerable population size fluctuations during the years that emphasize the importance of long-term studies. The best period for amphibian and reptile species monitoring is springtime, the reproducing season, when they can be observed in mass. In other periods of the year, amphibian species can be observed sporadically. That's why, two additional monitoring methods were used: occasional findings and information from local people. The river's basins were divided into three main zones: mountainous, between 800-1800 m; hilly, between 400-800 m; and hillock/plain, between 200-400 m altitude. Results The highest diversity of hcrpctofauna was observed in the hilly region, closely related to the wide variety of habitats. The number of observed amphibian and reptile species in the mountain zone is decreased in contrast with the hilly region (Ghira, 1997; Mara ct al., 1999). The low diversity of herpctofauna in the plain areas is explained by the ecosystem's monotony due to the intensive agriculture. We notice the dominance of Rana esculenta complex, Laceria agilis and Nairix natrix in every region, while Bombina variegala and Angiiis fragilis appear to be common species of the hilly region. The other amphibian and reptile species seem to be vulnerable, rare or endangered. We identified the major threats for amphibian and reptile species in the investigated river's basins as follows: 1. Destruction of wetland habitats (the amphibians, due their biphasie life cycle, at least during the breeding season and larval development are closcly related to these habitats): - Desiccation works, drainage of wetlands (river régularisation works); - Transforming backwaters in fishponds, introducing non-native fish species; - Intensive agriculture (use of fertilizers and pesticides, mowing) - Scorching of reeds, well vegetated adjacent areas. 2. Water pollution, eutrophication. 3. Destruction of rocky ecosystcms. 4. Deforestation, forest fires (damaging hibernation sites). 200 5. Road mortality (killing amphibians on their spring migration and reptiles by traffic). 6. Human consume (springtime, in some places frogs arc traditionally consumed and collected in mass by local people). 7. Tourism, human brutality (killing snake and lizard species, such as Anguis fragilis). Discussion The most important factor in the declinc of hcrpctofauna from Transylvanian river's basins is the loss of natural habitats. The amphibian species arc affcctcd by the destruction of rcproducing/brccding sites (freshwater ecosystcms) and hibernation sites as well (terrestrial ecosystems). The lack of important reptile fauna elements is due to the destruction of rocky ecosystems and deforestation. The breeding sites (pools, puddles, ponds) of newt species are polluted or even destroyed. In mountain regions the alpine (Triiurus alpestris) and Carpathian newt (Triiurus montandoni) is threatened mainly by deforestation and destruction of small temporary pools by the wood-exploitation works (Necas et al. 1997). Anthropogenic effects, as pollution and destruction of springs and streams, cause the low number of spotted salamander (Salamandra salamandra). The reduction of suitable habitats causes habitat fragmentation and the isolation of populations. When extinction can no longer be compensated by recolonisation, the population becomes weaker and even extinct. The same factors causc the reduction of anuran populations. For the fire-bellied toads (Bombina bombina) the most important factor is the loss of habitat (Briggs, 1997) as a conscqucncc of river régularisation works. Bombina bombina. Pelobates fuscus, Hyla arborea and Bufo viridis are declining rapidly in Denmark due to disappearance of ponds (33%), water pollution/eutrophication (30-40%) and fish introduction (Fog, K., 2000). The common toad (Bufo bufo) is threatened mainly by destruction of suitable freshwater and terrestrial habitats, and losses can also be caused by habitat fragmentation by roads. The most run over amphibian corpses belong to this species, because it is the slowest one. The brown frog species (Rana arvalis, R. temporaria, R. dalmalina) - beside the common threats - are consumed by local people. In springtime hundreds of frogs, sometimes common toads are butchcrcd. The populational fluctuation of Rana dalmatina in Acroe (Denmark) was caused partly by intensification of agriculture and partly by climate changes (Briggs, 1997). The intensive agricultural practices, using pesticides and fertilizers, cause water pollution, and in the same time lead to the accumulation of pollutans in the organisms of the whole food chain. The swamp turtle (Emys orbicularis) is threatened mainly by habitat reduction and other anthropogenic interventions. The lizard and snake species arc also threatened by habitat destruction (the reduction of rocky ecosystcms and deforestation). In the same time, the human brutality and the road traffic causc losses in their populations. 201 Humans kill adder species (Vipera beriis. Vipera ammodytes) and Coronela austriaca often misidentificd as common adder. The slow worm (Anguis fragilis) is the only snake-shaped lizard specics in the Romanian herpctofauna that is victim of human brutality. Habitat fragmentation and the negative effect of roads also have to be mentioned. Conclusions and proposals During the investigation two additional monitoring methods were used, occasional findings/visual observation and obtaining information from local people. The last method may give information on particular species that were previously recorded in the study area. Wc consider that it is the time for quantitative field research, for a better study of herpctofauna conservation status. We propose the following monitoring methods: 1. Line counting method. It can be performed in habitats or on road by visual observation, and the counting lines always have a fixed length (Masing, 1997). The road transcct method is optimal if environmental conditions are optimal, even a single night can provide reliable data on the presence of amphibian species. Besides the breeding migration in spring, the summer migration of juveniles, or autumn migration can be effectively studied (Puky, 2001). 2. Road counting call method. It was first used as monitoring method in Canada. A relatively straight route consisting of 10 sample points (with 0.5 km distance one from another) without extraneous noise has to be chosen, and is preferably to reflect a variety of good amphibian habitats such as pons, marshes or swamps (Anthony & Puky, 2001). 3. Square counting method. Is a modification of the quadrate sampling method, described by Jaeger & Inger in 1994, and the counters choose the squares in suitable habitats, where it is expected to find a large number of amphibians and reptiles. The counts are calculated per hectare (Masing, 1997) 4. Trapping methods. The point counting method (man-made holes) and the cone counting method (digging metal or plastic cones into the ground) also can be used for monitoring actions. Both are in fact close to the pitfall traps method, and can be used selectively for certain species (Masing, 1997). References Anthony, B & Puky, M. (2001): Kétéltűek hang alapján történő monitorozása (Road call count monitoring manual of Hungary), Varangy Akciócsoport Egyesület / Central European University, Budapest. 202 Briggs, L. (1997): Recovery of Bombina bombina in Funen County, Denmark, Memoranda Soc. Fauna Flora Fcnnica 73:101-104. Fog, K. (2000): Amphibian conservation in Denmark, Frolog 13 (on line) Ghira, I. (1997): Herpctofauna of Cri$ul Rcpcdc/Sebcs Körös and Barcáu/Bercttyó river basins. The Cri§/Körös River's Valleys, Tiscia monograph scries, 353-360. Ghira, I., Vencel, M., Covaciu-Marcov, S., Mara, Gyöngyvér, Ghile, P., Hartel, T., Török, Zs., Farkas, L. Racz, T., Farkas. Z. & Brad, T. (2002): Mapping of Transylvanian herpctofauna (in press) Griffiths, R.A. & Beebee, T. (1992): Dccline and fall of the amphibians. New Scientist, 1826: 25-29. Mara, Gyöngyvér, Ghira, I. & Farkas. L. (1999): Preliminary report on herpctofauna of the upper and middle Olt river basin, Transylv. Rev. Syst. Ecol. 1:169-181. Masing, M. (1997): Methods used for monitoring amphibian population in Estonia, Memoranda Soc. Fauna Flora Fcnnica 73:119-124. Necas, P., Modry, D. & Zavadil, V. (1997): Czcch Rcccnt and Fossil Amphibians and reptiles - An atlas and field guide, Ed Chimaira, Frankfurt am Main. Puky, M. (2001): Hcrpctological methods: 1. On the use of the road transect method in surveying amphibians with examples from different zoogcographical regions of Hungary, Opusc. Zool. Budapest XXXIII: 75-81. Vos, C.C. & Chardin, J.P. (1998): Effects of habitat fragmentation and road density on the distribution pattern of the moor frog Rana arvalis, J. of Applied Ecol. 35: 44-56. GYÖNGYVÉR MARA Sapicntia University Faculty of Technical and Natural Sciences Department of Ecology R0-4100 Micrcurca Ciuc P-{a Libertátii 1. 203 

Major threats for amphibian and reptiles species in the Transylvanian rivers' basins : recommended monitoring methods

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Major threats for amphibian and reptiles species in the Transylvanian rivers' basins : recommended monitoring methods

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