Figure 22.4 Schematic representation of initial departure directions (arrows) of central European passerine species on their way to the Mediterranean, and the number of species concerned. From left to right: southwest migration (45 species); southeast migration (10 species); both directions (13 species); between southwest and southeast = funnel migration into the central Mediterranean Region (3 species); clear migratory divide (16 species). From Bairlein (1985d).

for feeding en route; or (3) they may lead to modification of the fattening programme, ensuring that birds accumulate sufficient fuel to get across the barrier without any en route feeding. The two latter consequences depend on modification of the endogenous control programme, especially with respect to orientation and fuel deposition.

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