Raluca Ioana Băncilă

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.

Environmental determinants of the old oaks in wood-pastures from a changing traditional social-ecological system of Romania.

Large, old trees are keystone ecological structures, their decline having disproportional ecological consequences. There is virtually no information available regarding the status and occurrence of old trees in traditional cultural landscapes from Eastern Europe. In this study, we explore the environmental determinants of the old oaks found in wood-pastures from a changing traditional rural landscape from Central Romania. Both the old oaks and the wood-pastures harboring them have exceptional cultural, historical, and ecological values, yet are vulnerable to land-use change. We surveyed 41 wood-pastures from Southern Transylvania and counted the old oaks in them. We then related the number of old oaks from these wood-pastures to a set of local and landscape level variables related to wood-pastures. We found 490 old oaks in 25 wood-pastures. The number of old oaks was positively related to the size of the wood-pasture and the amount of pasture and forest around it (500xa0m buffer), and negatively related to the proximity of the village. Furthermore, we found a significant interaction between the effects of sheepfolds in the wood-pasture and the size of the wood-pasture on the number of old trees, indicating a negative influence of sheepfolds on the number of old trees in smaller sized wood-pastures. There is an increasing risk for losing old trees in the traditional cultural landscapes due to the lack of formal recognition of these trees. Therefore, while presenting the positive example of local initiatives and citizen science, we argue for an urgent development and implementation of conservation policies along with education strategies targeting the old trees and rural communities from the changing traditional cultural landscapes of Eastern Europe.

A landscape-level study on the breeding site characteristics of ten amphibian species in Central Europe

Temporary ponds are characterized as being in natural or close to natural states in Central and Eastern Europe, especially those located in forested landscapes. As these ponds function as breeding sites for many amphibians, they represent an ideal target to explore the terrestrial and aquatic habitat preferences of different species. We surveyed 133 small ponds in a forested, hilly region of North-Central Hungary. The occurrence of ten amphibian species and amphibian species richness were compared to six pond-related habitat variables and the extent of four terrestrial habitat types in the area surrounding the ponds. Our results suggest that most species’ occurrence and species richness are chiefly related to pond characteristics, although terrestrial habitat variables could also be a determining factor in particular species. Whereas the majority of amphibian species prefer larger, hence more permanent water bodies with abundant aquatic vegetation, the common frog (Rana temporaria) chooses small, shallow wallow pits for breeding and has special requirements concerning terrestrial habitat composition. This could explain its restricted distribution in the area. Our results suggest that maintaining a diverse set of ponds and forestry management which facilitates habitats’ structural heterogeneity are both important factors for the preservation of the rich amphibian fauna in Central Europe.

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.

The influence of environmental variables on soil mite communities (Acari: Mesostigmata) from overgrazed grassland ecosystems – Romania

Abstract In 2013–2014, the soil mite communities from six overgrazed grassland ecosystems located in the Trascău Mountains, Romania, were investigated. Forty-six species were identified, with 645 individuals. Some abiotic factors from soil were measured (soil temperature – T, soil water content – H, soil acidity – pH, carbon content – C, total nitrogen – Nt, and C/Nt ratio). Significant statistical differences were obtained between environmental factors. Using a canonical correspondence analysis of mite species abundance, environmental variables and habitats, strong relationships between investigated factors were established.

Factors influencing the breeding habitat use by amphibians in the alpine area of the Retezat National Park (Romania)

Factors influencing the breeding habitat use by amphibians in the alpine area of the Retezat National Park (Romania) We analyzed the distribution of amphibians according to the characteristics of breeding ponds in the alpine areas of the Retezat National Park. We inventoried 50 aquatic habitats between 1920 and 2260 m a.s.l. Three amphibian species are present at high altitudes: Rana temporaria, Bufo bufo and Mesotriton alpestris. They were found in 70% of the aquatic habitats, but only 48% were used as spawning sites. Human impacts and predators were the most influential variables explaining the occurrence of R. temporaria, whereas location and pond adjacent terrain were important for M. alpestris. Moderate grazing had a positive effect by maintaining low vegetation or providing nutrients input in the oligotrophic aquatic habitats. Factori ce influenţează utilizarea habitatelor acvatice de către comunităţile de amfibieni din zona alpină a Parcului Naţional Retezat (România) Modul în care speciile utilizează habitatele este important pentru conservarea biodiversităţii. Populaţiile de amfibieni ce ocupă habitate în zone situate la altitudini ridicate sunt mai vulnerabile la schimbările climatice decât cele de la altitudini scăzute. Am analizat accesibilitatea habitatelor acvatice şi utilizarea acestora de către speciile de amfibieni în două zone situate la altitudini ridicate în Parcul Naţional Retezat ce ocupă o suprafaţă de aproximativ 2400 ha. În zona studiată (altitudine 1920-2260 m) au fost inventariate 50 de habitate acvatice. Cele trei specii de amfibieni (Rana temporaria, Bufo bufo şi Mesotriton alpestris) sunt prezente în 70% din habitatele acvatice inventariate, dar numai 48% dintre acestea sunt utilizate pentru reproducere. Variabilele care influenţează cel mai mult prezenţa speciilor sunt impactul uman, prezenţa prădătorilor şi caracteristicile habitatelor acvatice pentru R. temporaria şi altitudinea şi zona terestră limitrofă habitatelor acvatice în cazul lui M. alpestris. Impactul uman moderat reprezentat de păşunatul alpin poate avea efecte benefice prin intrările de nutrienţi în lacurile oligotrofe şi prin facilitarea dispersiei indivizilor. Nous avons analysé laccessibilité des habitats et leur utilisation par les espèces damphibiens en deux zones situées à haute altitude dans le Parc National Retezat, qui occupent une superficie denviron 2400 ha. Dans la zone étudiée (altitude 1920-2260 m) on a inventorié 50 habitats aquatiques. Les amphibiens (Rana temporaria, Bufo bufo et Mesotriton alpestris) sont présents dans 70% des habitats aquatiques inventoriés mais seulement 48% de ceux-ci sont utilisés pour la reproduction. Les variables qui influencent le plus la présence des espèces sont limpact humain, la présence des prédateurs et les caractéristiques des habitats aquatiques pour R. temporaria et laltitude et le terrain environnant dans le cas de M. alpestris. Limpact humain modéré peut avoir des effets bénéfiques par lentrée de nutrients dans les lacs oligotrophes et en facilitant la dispersion des individus.

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.

Small-scale spatial and temporal variation of life-history traits of common frogs (Rana temporaria) in sub-Arctic Finland

Small-scale spatial and temporal variation in abiotic and biotic environmental conditions can lead to large differences in mean values of important life-history traits in ectothermic vertebrates, such as amphibians. However, relatively little is known about small-scale variation in life-history traits of sub-Arctic amphibians. We studied the spatio-temporal variation of adult life-history traits linked to age and body size in the common frog (Rana temporaria) from low (i.e., valley at 480xa0m a.s.l.) and high (i.e., hill at 530–650xa0m a.s.l.) altitude sites in the sub-Arctic Kilpisjärvi area (Finland). Data on life-history traits of frogs from hill sites collected during a 3-year field study were compared with previously published data from the valley sites. The results showed spatio-temporal variation in life-history traits, frogs responding to spatio-temporal variation in the environmental conditions with variation in age, life span, survival rates, body size, and mass. Frogs from hill sites had shorter life span, both in terms of mean age (5.6 versus 10.5xa0years) and longevity (9–10 versus 18 years), smaller snout-vent length (63 versus 77xa0mm), and body mass (24 versus 45xa0g) than frogs from valley sites. The differences were more pronounced in females than in males indicating some sex-specific responses to environmental differences among sites. The results show that small differences in elevation (or elevation-related abiotic and biotic factors) can translate to large differences in mean values of important life-history traits in common frogs living at the edge of their distribution range.

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.