Shelduck only occur in dry seasons. They fall easy victims to any sort of "decoy" provided it is _white_. A local fowler told us he had killed many by substituting (in default of natural decoys) the dry bones and skulls of cattle! Ruddy shelduck do not frequent the marisma, preferring the sweeter waters and shallows adjoining Doñana.
Diving-ducks avoid the marisma except only in the wettest winters.
An hour before sun-down, as above stated, all bird-movement ceases. For a brief space absolute tranquillity reigns over the illimitable marisma. The dusky masses that cover the _lucios_ seem lulled to sleep and silence. But the interlude is very temporary. Hardly has night thrown her mantle across the wastes, than all that tremendous, eager, vital energy is reawakened to fresh activities. A striking and a memorable experience will be gained by awaiting that exact hour at some favourite feeding-ground. Within a few minutes, as darkness deepens, the ambient air fairly hisses and surges with the pulsation of thousand strong pinions hurtling close by one's ear, and with the splash of heavy bodies flung down by fifties and hundreds in the shallows almost within arm's-length--the nearest approximation that occurs to us is a bombardment of pompoms. Yet, for all that, night-flighting in the marisma (having regard to the quantities concerned) produces but insignificant results. The ducks come in so low and so direct--no preliminary circling overhead--and at such velocity that this flight-shooting may be likened to an attempt to hit cannon-balls in the dark. Our expert shots score, say, eight or ten, but what is that? The nocturnal disturbance, moreover, may be (and usually is) prejudicial to the next day's operations, and it is clearly not worth the risk, for half-a-dozen shots in the twilight, to discount a hundred at dawn.
The fewer shots ducks hear, the better. Never disturb them unless you have every reasonable prospect of exacting a proportionate toll.
To Spain, as to other lands that remain unaltered and "unimproved," resort the greylag geese in thousands to pass the winter.
In our marismas of the Guadalquivir they appear during the last days of September, but it is a month later ere their full numbers are made up, and from that date until the end of February their defiant multitudes and the splendid difficulties of their pursuit afford a unique form and degree of wild sport perhaps unknown outside of Spain.