No abstract

Traffic intensification, often in conjunction with habitat fragmentation, has caused frequent roadkill incidents, particularly among reptiles, amphibians, and other taxa. Herpetofauna species, which are slow moving and habitat dependent, are particularly susceptible to these incidents because they often use roads during thermoregulation. Lesvos, the eighth-largest Mediterranean island, boasts a biodiversity that surpasses most other Mediterranean islands of similar or larger size, with a plethora of herpetofauna species inhabiting its terrain. In recent years, new roads were constructed on Lesvos, which are considered to be one of the most important factors that negatively affect the island’s wildlife as they increase the non-natural mortality of animals, are obstacles to their mobility, and reduce the connectivity of populations by limiting their dynamics. In the present study, we examined the road mortality of amphibians and reptiles by analyzing (a) the temporal and seasonal patterns of such incidents, (b) the relationship between roadside habitats and road network characteristics with the roadkilled herpetofauna species, and (c) their spatial distribution on Lesvos during the years 2009–2012 and 2016–2019. To identify significant clusters of reptile and amphibian roadkills, we performed hotspot analysis by utilizing kernel density estimation and Getis Ord Gi* statistics. We recorded a total of 330 roadkills among 20 species, with the highest rates emerging among the European green toad (Bufotes viridis), the European glass lizard (Pseudopus apodus), the Rhodos green lizard (Lacerta diplochondrodes), and the snake-eyed lizard (Ophisops elegans). Spatial statistical analysis revealed that roads close to herpetofauna habitats exhibit statistically significant clusters of roadkills that intensify during the spring season. Regular monitoring and mapping of herpetofauna road mortality will enable the implementation of management strategies to mitigate the negative impact of this phenomenon.

The Karpathos water frog (Pelophylax cerigensis) is classified as Critically Endangered according to the IUCN Red List and its distribution is restricted on the island of Karpathos, South Aegean Sea. Utilizing a next generation sequencing approach, we obtained whole mitochondrial genomes of P. cerigensis to determine the species phylogenetic position within the genus Pelophylax and to clarify the phylogenetic relationship between the species’ population on Karpathos Island and the population of P. cf. bedriagae from the neighboring Rhodes Island. High-throughput sequencing generated mean ± SD = 227 945 ± 18 306 reads averaged per sample. High quality reads were assembled resulting in the complete mitogenome of P. cerigensis of a total size of 17 922 bp. Mitogenome organization was similar to other Pelophylax species, comprising of 13 Protein Coding Genes (PCGs), 22 tRNAs, two rRNAs and one Control Region. Overall mean genetic distance for the 13 PCGs, within the Ranidae family, ranged from 8.01% (COIII) to 11.6% (ATP8), while ratios of synonymous and non-synonymous substitutions were <1 in all the 13 PCGs, indicating purifying selection. Maximum Likelihood and Bayesian Inference analyses based on the concatenated sequences of 13 PCGs and two rRNAs (12S and 16S), showed that individuals from Karpathos and Rhodes form a well-supported monophyletic group with low genetic distance between them (p-distance = 0.1%). Hence, the Rhodes populations seem to belong to P. cerigensis and not to P. bedriagae as formerly thought, highlighting the need for revision of P. cerigensis current conservation status as well as further examination of the P. bedriagae species group.

One of the most successful predators on island ecosystems is the domestic cat, which is considered responsible for the decline of numerous species’ populations. This can be estimated by the analysis of cats’ dietary habits, yet prey identification is not always possible, and thus, in cases where precise prey identification is required, one of the most accurate methods derives from observing the hunting process. However, the cryptic nature of the feral cats and the constant vigilance of the species that are preyed upon make the observation process difficult, especially when the prey has a low population density. Here, we report for the first time such a case: a feral cat that has ambushed, killed, and consumed a regionally near-threatened species, the Persian squirrel. This incidental observation happened in the squirrel’s westernmost end of its distribution, the island of Lesvos, Greece. Due to the unexpectedness of the event, in the following days, we estimated both the squirrels’ and cats’ population density. Results showed that while the density of the squirrels is moderate, the population density of the feral cats is almost fifteen times higher. For this reason, management actions need to be taken in an effort to minimize the impacts of feral cats on the native species of the island.

Despite a recent shift towards sustainable practices to support the conservation of traditional olive groves, little is known about their potential threats to herpetofauna species. On the island of Lesvos, one of the main olive-growing islands in the Mediterranean, olive cultivation often prioritizes the expeditious harvesting of olives with minimal or no supplementary intervention, resulting in their generally suboptimal management, a component of which also pertains to the olive nets that, in many cases, remain dispersed and unfurled throughout the groves. This particular practice affects the species living in the olive groves, making them more prone to risks related to their accidental trapping. In this study, we report the first case of a Grass snake being inadvertently trapped in an olive net laid out on an olive grove. The position of the snake under the net, within a folded tipping, made it difficult for it to escape, and it became increasingly entangled. Based on this incident, it is plausible to assume that similar cases may occur in areas where nets are used in olive groves, both in Greece and other olive-growing countries. Further systematic research is necessary to determine the extent of this issue.