Pool Frog Rana Lessonae Research Articles

Amphibian communities in small water bodies in the city of Olsztyn

The aims of the study were determine the effects of anthropogenic pressure on the species composition and population size of amphibians of small water bodies in Olsztyn city (NE Poland). The presence of 11 amphibian species was noted in 83.5% of water bodies. The dominants were: the common frog Rana temporaria, the edible frog Rana esculenta, the pool frog Rana lessonae, the common toad Bufo bufo and the moor frog Rana arvalis. The fire-bellied toad Bombina bombina was an influent, while the common newt Triturns vulgaris, the common spadefoot Pelobates fnsciis, the tree frog Hyla arborea, the green toad Bufo viridis and the crested newt Tritimis cristatus were the recedents. The most frequent were “green frogs”, which occur in 71.9% of water bodies inhabited by amphibians (60.0% of all water bodies). The species characterized by the lowest occurrence frequency were the tree frog (6.0% and 5.0%, respectively), the green toad (5.4% and 4.5%) and the crested newt (3.6% and 3.0%). In the paper the urban pressure on amphibian communities is widely discussed.

Neglected native or undesirable alien? Resolution of a conservation dilemma concerning the pool frog Rana lessonae

Introduced species often pose serious threats to biodiversity, but occasionally confusion arises as to whether a species really is introduced or is in fact an overlooked native. A recent UK conservation dilemma has centred on the status of the pool frog Rana lessonae. This species has been the subject of documented introductions from central and southern Europe since the early 1800s, the accepted position being that all UK R. lessonae populations are descended from these introductions. However, a closer examination of early UK literature sources, and recent discoveries of isolated, native R. lessonae populations in Sweden and Norway, led some herpetologists to question whether the species was in fact present as a native at some locations prior to the introductions. Research was initiated along four major lines of enquiry: genetic, bioacoustic, archaeozoological and archival. A high degree of convergence among the genetic and bioacoustic investigations demonstrated that the potentially native UK pool frogs were closely related to Scandinavian frogs, thus ruling out introductions from further south as a potential origin. Subfossil evidence of pool frogs was found from ca. 1000 years before present, demonstrating that the species occurred in the UK prior to known introductions. Archival sources produced no historical support for introductions from northern Europe. The postglacial history inferred for these northern populations is consistent with the known climatic and geographical conditions. Taken together, the evidence for the native status of the pool frog is compelling, and furthermore the UK population appears to be part of a distinct northern clade.

Distribution of amphibians and reptiles in central Poland: 1980-2000

Based on 3047 records from 97 recorders distribution maps were drawn for the amphibians and reptiles of central Poland (lirom 51°00’N to 52°15’N and from 18°20’E to 20°20’E). The study area was divided into 180 atlas fields based on the geographic grid. All data were gathered in 1980-2000, most of them (67%) however, in 1995-2000. 13 taxa of amphibians were found in 143 atlas fields and 6 species of reptiles were found in 121 atlas fields. The amphibians were (given with the number of atlas fields with the species found): 119 - Common frog Rana temporaria Linnaeus, 1758; 114 - Common toad Bufo bufo (Linnaeus, 1758); 97 - Moor frog Rana arvalis Nilsson, 1842; 94 - Fire-bellied toad Bomhina bombina (Linnaeus, 1761); 93 - Pool frog Rana lessonae Camerano, 1882; 87 - Tree frog Hyla arhorea (Linnaeus, 1758); 85 - Green toad Bufo viriiüs Laurenti, 1768; 72 - Smooth newt Triturus vulgaris (Linnaeus, 1758); 70 - Spadefoot Pelobales fuscus (Laurenti, 1768); 69 - Edible frog Rana kl. esculenia Linnaeus, 1758; 39 - Great crested newt Triturus cristatus (Laurenti, 1768); 30 - Marsh frog Rana ridibunda Pallas, 1771 and 28 - the Natterjack Bufo calamita Laurenti, 1768. The reptile species (given with the number o f atlas fields) were: 94 - Sand lizard Lacerta agilis Linnaeus, 1758; 72 - Slow-worm Anguis fragilis Linnaeus, 1758; 67 - Common lizard Lacerta vivipara Jacquin, 1787; 60 - Grass snake Natrix natrix (Linnaeus, 1758), 57 - Adder Vipera berus (Linnaeus, 1758) and 4 - the Smooth snake Coronella austriaca Laurenti, 1768. Six adult specimens of the European pond terrapin Emys orbicularis (Linnaeus) were also found, but breeding of this species in the area studied was not confirmed.

Frog calls echo microsatellite phylogeography in the European pool frog (Rana lessonae)

AbstractVocalization is an important component of male reproductive behaviour in a wide range of animal taxa. In some species there is considerable intraspecific variation of call characters partitioned on a regional basis. Such ‘regional accents’ could originate from cultural or genetic evolution and have been widely studied in birds. Amphibians, however, have limited learning abilities, and where regional accents occur in this group they are primarily a consequence of genetic evolution. This raises the possibility that regional variations in anuran call characters might be informative about phylogeographic history. Microsatellite studies of the pool frog Rana lessonae have been used previously to infer patterns of post‐glacial colonization in Europe, with unexpectedly complex implications for northernmost populations of this species. Therefore, regional variation in call characters of the pool frog was quantified and the pattern observed was concordant with the differentiation of a distinct northern clade as implied by the microsatellite study. We therefore conclude that regional accents in this amphibian are useful phylogeographic indicators of distribution history.

The Effect of Assortative Mating on the Coexistence of a Hybridogenetic Waterfrog and Its Sexual Host

In central Europe, the hybridogenetic waterfrog Rana esculenta, a hybrid between Rana ridibunda and Rana lessonae, lives in sympatry with one of its parental species, the poolfrog Rana lessonae. As R. esculenta has to backcross constantly with R. lessonae in order to produce viable offspring, this coexistence is obligatory for R. esculenta. Since R. esculenta has a higher primary fitness than R. lessonae, a mechanism is required that prevents the hybrid from driving the parental species, and hence itself, to extinction. Here, we present an analytical model and a computer simulation that investigate whether assortative mating can operate as a such a control mechanism. Our results show that assortative mating is very effective in regulating coexistence in such a hybrid-host system. This is particularly true when choice is affected by the proportion of the two male types in the population. Furthermore, we could show that even if the species composition in a mixed hybrid-host population may be largely influenced by differences in life-history parameters, assortative mating still plays a very important role by stabilizing coexistence. Thus, mating behavior turns out to be more important for the populations dynamics of hybridogenetic waterfrog systems than previously assumed.

The Effect of Assortative Mating on the Coexistence of a Hybridogenetic Waterfrog and Its Sexual Host

In central Europe, the hybridogenetic waterfrog Rana esculenta, a hybrid between Rana ridibunda and Rana lessonae, lives in sympatry with one of its parental species, the poolfrog Rana lessonae. As R. esculenta has to backcross constantly with R. lessonae in order to produce viable offspring, this coexistence is obligatory for R. esculenta. Since R. esculenta has a higher primary fitness than R. lessonae, a mechanism is required that prevents the hybrid from driving the parental species, and hence itself, to extinction. Here, we present an analytical model and a computer simulation that investigate whether assortative mating can operate as a such a control mechanism. Our results show that assortative mating is very effective in regulating coexistence in such a hybrid‐host system. This is particularly true when choice is affected by the proportion of the two male types in the population. Furthermore, we could show that even if the species composition in a mixed hybrid‐host population may be largely influenced by differences in life‐history parameters, assortative mating still plays a very important role by stabilizing coexistence. Thus, mating behavior turns out to be more important for the populations dynamics of hybridogenetic waterfrog systems than previously assumed.

Thermal preference in the pool frog Rana lessonae: impact on the reproductive behaviour of a northern fringe population

A documented warmth preference in the pool frog Rana lessonae is also expressed in the reproductive behaviour of a northern fringe population (60°N). During the breeding period of 31 days, individually marked frogs were observed during chorus. Male choruses were formed in the warmest parts of the pond, but moved between three areas. At night, these areas maintained the highest water temperatures in the pond, especially at low temperatures prevailing in the beginning of the breeding period. Oviposition occurred in the current chorus areas, and 86% took place during the first two weeks of the breeding period. That the choruses and oviposition changed locations within the favourable breeding areas can be explained by a pronounced thermal preference in the frogs, and winds moving the warm surface water in different directions.The water temperature required to initiate oviposition was 16°C, which is similar to those reported from related more southern populations. The thermal preference expressed in the breeding behaviour of both sexes and the tendency for early oviposition may be behavioural responses to environmental constraints on reproduction in the short season at 6O°N.