Rodica Plăiaşu

Comparing three body condition indices in amphibians: a case study of yellow-bellied toad Bombina variegata

Body condition is important because it is correlated with population and habitat quality parameters. Since the direct measurements are either lethal or unreliable, a wide range of non-lethal body condition indices has been proposed. The aim of our study was to apply and compare three body condition indices (Fultons index, relative body condition mass index and residual index) using body size indicator - body mass data for 24 populations of the yellow bellied toad (Bombina variegata). The condition index should be independent of body size indicator, in this case snout vent length (SVL). Therefore we tested all three indices for the statistical independence of SVL and for the normality of distribution. Fultons index violated the independence assumption, whereas the relative body condition mass index did not have a normal distribution. Residual index was found both independent of SVL and normally distributed. Moreover, the residual index highlighted biological significant differences on the basis of altitude and season. Our results recommend the residual index as a useful tool in amphibian monitoring and conservation.

Diversity and distribution of amphibians in Romania

Abstract Nineteen species of amphibians inhabit Romania, 9 of which reach their range limit on this territory. Based on published occurrence reports, museum collections and our own data we compiled a national database of amphibian occurrences. We georeferenced 26779 amphibian species occurrences, and performed an analysis of their spatial patterns, checking for hotspots and patterns of species richness. The results of spatial statistic analyses supported the idea of a biased sampling for Romania, with clear hotspots of increased sampling efforts. The sampling effort is biased towards species with high detectability, protected areas, and large cities. Future sampling efforts should be focused mostly on species with a high rarity score in order to accurately map their range. Our results are an important step in achieving the long-term goals of increasing the efficiency of conservation efforts and evaluating the species range shifts under climate change scenarios.

Estimation of apparent survival probability of the harvestman Paranemastoma sillii sillii (Herman, 1871) from two caves

Reliable estimates of population parameters are lacking for most cave-dwelling species. This lack of knowledge may hinder the appropriate management of caves and populations of cave-dwelling species. Using monthly capture-recapture data and Cormack-Jolly-Seber models, we (i) estimated the apparent survival of individuals in two cave populations of the harvestman Paranemastoma sillii sillii (Herman, 1871) from the Mehedinti Mountains in south-western Romania; (ii) investigated temporal variation in apparent survival; (iii) tested if surface weather conditions affect apparent survival of cave-dwelling harvestmen through their influence upon cave environmental conditions and (iv) tested for sex differences in apparent survival. Our results show that the apparent monthly survival estimates were high for both studied cave populations and there was a significant sex effect on survival. Males had lower survival than females, and the survival difference between caves was larger in males than in females. Temporal (i.e., monthly) variation in apparent survival was low and the weather conditions at the surface had little influence on apparent survival as the environment inside the caves is well buffered against weather fluctuations outside the caves. Our results indicate that caves stabilize survival of facultative cave-dwelling species and may serve as microrefugia for epigean species. We suggest that caves should be considered for conservation because they may serve as a refuge for some epigean species during harsh weather conditions.

Fluctuating Asymmetry in the Eurasian Spur-Thighed Tortoise, Testudo graeca ibera Linneaus, 1758 (Testudines: Testudinidae)

Abstract We studied plastron-shaped asymmetry of the Eurasian Spur-Thighed Tortoise, Testudo graeca ibera, as related to life stage, gender, and distribution. Our analyses of 523 individuals showed that fluctuating asymmetry (FA) in plastron shape varied with gender (males exhibited higher levels of FA than did females) and across populations, whereas life stage had no significant effect. Although we could not identify the potential sources of variation responsible for the observed patterns of developmental instability, our study shows the value of FA as a method for studies of developmental instability in turtles.

Fluctuating asymmetry as a bio-marker to account for in conservation and management of cave-dwelling species

The applicability of fluctuating asymmetry (FA) in conservation biology as a bio-marker and an early warning system have been examined in various groups of animals. However, cave-dwelling invertebrates have gotten little attention and yet caves have no biological management. Thus, developing a bio-marker to identify early responses of cave-dwelling species to stress provides a valuable tool to account for in future conservation and management programs. We examined whether FA can be used as a bio-marker of relaxed selection for cave-dwelling invertebrates. Specifically, we compared FA levels of pedipalps and two segments of chelicerae (chelicel1 and chelicel2) between cave and surface habitats and among populations in a troglophilic harvestman specie, Paranemastoma sillii sillii (Herman, 1871). Under the assumption that cave environment exerts relaxed selection we hypothesised that cave-dwelling harvestmen express higher degree of FA than surface-dwelling harvestmen. Because female and male harvestmen use the pediplaps differently, we assumed sex-specific selective pressures and further examined the effect of sex and habitat (cave vs surface) and sex interaction on FA levels. We hypothesised no differences in the levels of FA among harvestman cave populations, because of the idea that relaxed selection is responsible for higher levels of FA in cave-dwelling harvestmen rather than environmental stress. We found significant habitat sex interactions in the FA of the pedipalp. Interactions of population and sex had a significant effect on pedipalp and chelicel2 FA. These results partially support the idea that FA responds to differences in the strength of selection. Although we cannot fully disentangle the mechanisms of natural selection affecting FA and the study of trait asymmetry should be combined with studies of other sources of stress (i.e. genetic stress, predation, prey availability) we conclude that FA could be a bioindicator to be used as a tool in conservation and management of cave.

The injuries on tortoise shells as a depository of past human impact

Abstract The spur-thighed tortoise Testudo graeca has a wide distribution encompassing southern Europe and the Middle East through to northern Africa. The populations at the northern limit of T. graeca’s range in the province of Dobrogea (Romania) are sparsely distributed across the entire area, with higher densities found in the hilly forested areas. Although strictly protected, the spur-thighed tortoise was and continues to be impacted by human activities. This study investigated the presence and characteristics of scars from past injuries on their shells. We studied three populations from protected areas, situated along a north–south gradient of approximately 150 km: Măcin Mountains National Park (northernmost limit of T. graeca’s range), Cetatea Histria, located within the Danube Delta Biosphere Reserve, in the central part of the region, and the Dumbrăveni Forest Natural Reserve in the south. All three populations had individuals with scars from past injuries on their shells. The highest numbers of injured tortoises were in Dumbrăveni Forest (35.78%) and Măcin Mountains (35%) while the population from Cetatea Histria (11.26%) was less affected. Carapace injury frequency was higher in the Măcin Mountains whilst the Dumbrăveni Forest population had a higher frequency of plastron injuries. Human-caused injuries were observed mainly in the anterior and dorsal zones of the carapace and the anterior zone of the plastron. Natural injuries were located on the posterior zone of the carapace, mainly on marginal scutes. Our study showed that the scars of turtle shells proved to be an excellent depository of past and recent human impacts and may offer insights for better conservation and management strategies.