CHAPTER VI
THE DISTANCES TRAVELLED BY BIRDS
Not only do the distances of the migration paths of different species vary considerably, from a trip of a few miles to a voyage from the Arctic to the Antarctic, but the individuals of one and the some species do not all travel to the same degree.
The familiar swallow, Hirundo rustica, though subject to certain geographical variations, is found throughout the Palæarctic and Nearctic regions, nesting throughout Europe to between 63° and 70° north and in Africa north of the Sahara, where, however, Canon Tristram found it also wintering in the oases. South of the Sahara to the Cape it is a winter visitor. In Asia it breeds, according to Seebohm, in Asia Minor, Persia, Afghanistan, and western Siberia, and winters in Scinde and western India. One form breeds in and north of the Himalayas, eastward to China and Japan, and Winters in India, and Burma, and another ranges from eastern Siberia, across Behring Strait throughout North America, so far south as Mexico. This form winters in Burma, in Central America and
