Patterns of partial migration of the Dead Sea Sparrow (Passer moabiticus) along the Great Rift Valley in Israel

Partial migration occurs when a population of animals contains both migratory and resident individuals. Following anthropogenic changes, the population of Dead Sea Sparrows (Passer moabiticus) in Israel, experienced a rapid expansion of its breeding range, from the Dead Sea northward along the Great Rift Valley. Appropriate climatic conditions, increased water availability and suitable trees to construct their nests enabled the Dead Sea Sparrows to breed in new areas. However, during non-breeding seasons, the climatic conditions and food availability is less suitable in some of these new areas. Dead Sea Sparrows colony, in an oasis in the Judean desert near the Dead Sea, was found to be mainly sedentary. However, recapture data, collected from numerous ringing projects along the Great Rift Valley, showed patterns of partial migration of northern populations. These include a unique altitudinal migration from above to below sea level. Female and juvenile Dead Sea Sparrows from northern populations migrate in autumn further south and in greater numbers than males and adults. This study sheds light on how the expansion of a passerine breeding range, due to anthropogenic activities, leads to the emergence of a variety of partial migration patterns.