Results of the First Herpetological Survey of Israel’s Mediterranean Coastal Islets

Abstract

Small islets in the Mediterranean Sea are often home to reptiles, typically representing an impoverished sample of the continental fauna, yet with high population densities and signs of rapid morphological and behavioral evolution. In this paper, we present the first herpetofaunal survey of several small islet clusters in close proximity to the Mediterranean coast of Israel, only recently geologically separated from the mainland. We performed surveys of five islets during March of 2017 – 2018 and recorded the presence of five different species of reptiles on four of the surveyed islets. Species richness varied between 1 and 4 species, and appeared to be correlated with island area, with a distinct nested structure. Reptile species may have colonized the islets by natural dispersal from nearby coastal populations, or by hitch-hiking on fishing boats and similar methods of human-assisted dispersal. Alternatively, the recorded reptiles may represent relictual populations from earlier geologic periods, when lower sea-levels supported continuous land-bridges between the islets and the mainland. These insular reptile populations require further study to establish the exact means of colonization and describe if and how they differ from mainland populations. We stress the importance of such small Mediterranean islets such as these as centers of unique biodiversity and encourage future study and conservation action aimed at them and similar islets.