Investigating ecological corridors and barriers to movement : a species approach for conservation

Abstract

Ecological corridors are crucial for the survival of species; they facilitate movement between different areas within a species’ home range, whilst aiding genetic exchange across the metapopulation, thus maintaining viable their populations. Despite their importance, maintaining corridors for conservation purposes is no easy task, largely because of conflicts-of-use and related impacts, mostly resulting in habitat loss and fragmentation. This study takes a species-approach towards understanding ecological corridors across specific areas in the Maltese islands. The species selected for this study are the blue rock thrush, Monticola solitarius (Linnaeus 1758), the Old-World swallowtail butterfly, Papilio machaon melitensis (Eller, 1936) and the Mediterranean chameleon, Chamaeleo chamaeleon (Linnaeus 1758). These three faunal species are noteworthy, being of ecological significance, charismatic, and protected under different legal instruments. This study focuses on telemetry, wherein radio tags are affixed to a voucher specimen from each of the aforementioned species to follow their respective movements over an approximate period of two weeks of field monitoring. Appropriate permits were acquired from respective official agencies. The sites of release include Mdina, Comino and Buskett respectively. P. m. melitensis tagged individuals were recorded to undertake a short sea crossing between the islands of Comino and Gozo, subsequently, each making their way to the northern side of Gozo. Each butterfly is estimated to have covered a minimum distance of approximately 16.6 km in 17 days. C. chamaeleon was noted to remain within a woodland habitat without crossing into adjacent garrigue-dominated karst, with the tagged male demonstrating the most vagility from the monitored sample. Not enough data was collected for M. Solitarius to establish movement patterns due to complications which arose during field sessions. Based on present findings, the study proposes a number of recommended measures for ecological connectivity within the local context for the different target species researched