Note 17 — Chapter VIII · THE MARISMAS OF GUADALQUIVÍR THE DELTA

At the date in question (end of November) it is, of course, possible that this immigration was proceeding, not from the north, but from the south. That is, that these were fowl which, on their first arrival in Spain in September and October, had found the marisma untenable from lack of water, and had in consequence passed on into Africa, whence they were now returning, on the changed weather. But be that as it may, the route above indicated is that invariably followed by the north-bred wildfowl on their first arrival in Spain.