Life-history traits and the first demographic data of Iranian population of the West Asian Lemon-Yellow Tree Frog, Hyla savignyi (Audouin, 1827)

The life-history of an organism consists of its lifetime pattern of growth, development, storage, age, and reproduction. In this study, some life-history traits of Hyla savignyi were studied in populations from different parts of Iran. The microscopic and macroscopic analysis showed that testicular activity in H. savignyi is potentially continuous, reaching its peak level in April. Metamorphosis was completed in approximately 102 days after egg deposition, and body size at metamorphosis was 10 mm. Significant sexual size dimorphism was present in all populations, and a larger female asymptotic body size was observed (43.07 mm for females vs 41.16 mm for males). The adult survival rate (S) and life expectancy (ESP) were the same for both sexes (S = 0.73 and ESP = 4.2 years). Age and body size were positively correlated with each other for both females and males. Maximum longevity was recorded to be six years in both females and males, and ages of sexual maturity were estimated to be two or three years in breeding individuals. The adult sample age ranged from two to six years (mean age of females: 4.40±0.68 years; males: 3.63±0.13 years). Our data confirm the general patterns of body size variation and mean age in anurans and show that females are larger than males and live longer.

Sexual Size Dimorphism in Hyla Savignyi Audouin, 1827 (Anura: Hylidae) from Nasiriyah Province, Southern of Iraq.

This study aims at investigating the sexual size dimorphism phenomenon (SSD) in the frog of a tree population Hyla savignyi Audouin, 1827 (Anura: Hylidae) from the province of Nasiriyah, southern Iraq. Thirty-nine specimens (19 females , 20 males) were captured, Digital calipers measured sixteen metric characters to the closest 0.01 mm and released in their natural habitat. SPSS Statistics V22.0 has been used to conduct the measurement of the study. Statistical data analysis clarified that there is a significant difference between genders of the study sample, females larger than males.

A river runs through it: tree frog genomics supports the Dead Sea Rift as a rare phylogeographical break

Phylogeographical breaks can be viewed as regional hotspots of diversity where the genetic integrity of incipient species is put to the test. We focus on an understudied species transition from the Middle East, namely the Dead Sea Rift in the Levant region, which presumably divided the tree frogs Hyla savignyi and H. felixarabica. Combining multilocus genetic analyses (mitochondrial DNA and RAD-sequencing) with ecological niche modelling, we test whether the rift effectively acts as a biogeographical barrier preventing this pair from admixing and merging. The answer is yes: despite weak signs of introgression, all parapatric populations were assigned to either species without cyto-nuclear discordance. Yet, the projected distributions under present and glacial conditions largely overlapped in the area, meaning their current parapatric ranges do not represent an ecological transition. Instead, we hypothesize that H. savignyi and H. felixarabica are maintained apart by limited opportunities for dispersal across the barren Jordan Valley, combined with advanced reproductive isolation. Therefore, the Dead Sea Rift may represent a rare phylogeographical break, and we encourage international efforts to assess its contribution to the rich biodiversity of the Middle East.

Larval performance and oviposition habitat selection of the tree frog, Hyla savignyi, in response to conspecific larval density

Amphibians breeding in temporary pools may experience strong intraspecific density-dependent effects in the form of larval competition and oviposition site selection. These potential effects are untested for the tree frog, Hyla savignyi, an anuran species of conservation concern in Israel. We conducted an outdoor mesocosm experiment to examine how intraspecific larval density may affect larval performance and oviposition habitat selection in H. savignyi. We added ecologically relevant densities of 0, 10, or 40 early-stage tadpoles into mesocosms (plastic tubs) containing 20 L of water. Each density was replicated with four tubs. Time to and size at metamorphosis were not significantly affected by initial H. savignyi density. However, strong intraspecific competitive effects were observed in the form of reduced size at metamorphosis at the high density. We also found that gravid H. savignyi females reduce future intraspecific competition for their progeny by choosing to oviposit in mesocosms with no, or low, densities of H. savignyi tadpoles. Thus, intraspecific competition in this anuran species appears to be an important factor at ecologically relevant densities; larval competition increases with increasing densities and may be avoided by gravid females assessing breeding habitat quality in the form of conspecific tadpole density or mass.

Ecological divergence between two evolutionary lineages of Hyla savignyi (Audouin, 1827) in Turkey: effects of the Anatolian Diagonal

Most of Turkey’s land area is covered by one of three biodiversity hotspots (Caucasus, Irano-Anatolian, and Mediterranean). Anatolia is one of the main corridors for postglacial colonization of Europe. Uncovering how populations of a species differ genetically and ecologically is important for understanding evolutionary processes. Here, I examined ecological information to define ecological divergence between two lineages of Hyla savignyi. Using ecological niche modeling, I determined whether the two genetically divergent lineages of H. savignyi are geographically isolated and addressed the effect of the geographical distribution in the Anatolian Diagonal on the lineages. Separate analysis of the lineages showed no overlap of their predicted ranges based on climatic data of their respective habitats. This suggests that the lineages were formed as a result of range fragmentation during the Ice Age, and were consequently adapted to different climatic conditions.

Patterns of distribution of tree frogs in Turkey based on molecular data

Despite previous work on the phylogeny of Palearctic Hyla, several problems still exist regarding systematics of Hyla in Turkey. The systematics of tree frogs (Hyla orientalis and Hyla savignyi) in Turkey was studied using combined mitochondrial genes (12S ribosomal RNA and cytochrome b) and a nuclear gene (H3), and sampling a total of 102 individuals from 51 localities. We find that Hyla orientalis is represented by a single lineage, whereas Hyla savignyi was divided into two lineages by the mitochondrial genes, but not the nuclear gene. We also confirm that Hyla arborea schelkownikowi is a junior synonym of Hyla orientalis.