Species–area relationships and nestedness patterns were studied in three groups of small terrestrial vertebrates (mammals, reptiles, amphibians) on 14 landbridge islands of the eastern Adriatic. Islands ranged in surface area between 15 and 410 km2 and contained from eight to 36 species from a total species pool of 48. Reptiles were the most species rich group (S = 28), and had more species than mammals (S = 13) and amphibians (S = 7) combined. Island surface area predicted species richness best in reptiles (r2 = 0.79) and most poorly in amphibians (r2 = 0.52). Mammals showed a significantly lower slope of the species–area curve than amphibians and reptiles, and thus accumulated species counts with increase in area at the lowest rate. Nestedness patterns in all groups were significantly more organised than expected by chance. Amphibian nested structure points to extinction dominated and well insularised populations with no subsequent recolonisations. Frequent unexpected presences and absences in the nestedness patterns of mammals and reptiles suggest complex biogeographic histories for these two groups, with several factors putatively in operation: heterogeneity in habitats and the original source fauna, post- isolation immigrations and differential extinction rate due to human-caused habitat degradation.
The cranial and dental morphology of field mouse from the island of Rhodes suggests that they belong to Apodemus iconicus (=A. hermonensis) rather than to A. sylvaticus or any other Sylvaemus species. Morphological identification was supported by partial mitochondrial cytochrome b nucleotid sequences (370 bp long DNA fragment). Samples from the islands of Rhodes and Bozcaada shared 98% identity in nucleotide and 100% identity in amino acid sequences with Apodemus iconicus from Anatolia.