An Outline of the Zoogeography of the Levant 1

Por, F. D. (Department of Zoology, The Hebrew University of Jerusalem, Jerusalem, Israel.) An outline of the zoogeography of the Levant. Zool. Scr. 4 (1): 5–20, 1975.–The marine, freshwater and terrestrial distributional patterns in the region of the Eastern Mediterranean shorelands are discussed. Several historical formative events are singled out and especially the desertification of what is called the Palaeo‐eremic region. Thus a subtraction‐transition area between the Palae‐arctic and Ethiopian regions appeared. Faunal elements belonging to these three regions can be found in the area, admixed with a few Orienta species. The distributional pattern of the marine fauna is dominated by the faunal invasion from the Indo‐Westpacific region to the Mediterranean. The distribution of the freshwater animals more or less follows that of the terrestrial fauna with the important exception of the Oriental and Ethiopian fishes which took advantage of the steeplechase waterways leading from the Euphrates into the rivers of the Rift Valley. The humid tropical oasis enclaves as well as many of the freshwaters are the specific environments where most of the zoogeographically interesting species and endemics are found. These are precisely the environments which have most suffered from human interference. Summary (1) The Levant province is a meeting place and transitional area between the Palaearctic, Oriental and Ethiopian zoogeographic regions. In the marine world, its coasts are inhabited by the temperate Atlantic‐Mediterranean fauna and the tropical Indo‐Pacific fauna. (2) The broad “Palaeo‐eremic” desert belt serves as a filtering barrier between the three faunal regions. Inhabited by a peculiar fauna of mixed origin, the Palaeo‐eremic belt does not belong to any of the above‐mentioned regions. The ability to cross the desert barrier differs for the different taxa: it is maximal for mammals, birds and insects. Freshwater fish use a peculiar “steeple chase” waterway connecting the Nile with the Euphrates through the waterways of the Rift valley. The man‐made Suez Canal serves as a filtering pathway through which the Indo‐Pacific tropical fauna invades the Mediterranean. (3) In the terrestrial environments, the transition from the dominance of the Palae‐arctic species in the north to that of the Palaeo‐eremic species in the south, is complicated by the fourfold longitudinal geomorphological pattern of the area. Palae‐arctic species advance south along the cis‐ and trans‐rift mountain ranges, while Palaeo‐eremic and Ethiopian species extend northwards along the coastal plain and the Rift valley. The Indo‐Pacific emigrants to the Mediterranean advance northwards along the Levant coast, and their influence gradually decreases towards the north. (4) The Levant province has suffered the most profound human impact for some 10 000 years. Nevertheless, there are some endemic species in the area. These are animals of Palaeo‐eremic or Ethiopian character, especially concentrated in the waters and oases of the Rift valley. The wealth of the marginal populations in the zoogeographic, ecological, and physiological sense, makes protection of species and habitats especially important.