380 Unexplored Spain 
courting and sorting. Adult ducks, as previously indicated 
(p. 110), apparently pair for life; but since some species (such as 
wigeon) take at least two years to gain maturity, it is probable 
that the sexual phenomena which are so conspicuous in the corros 
represent the first pairing of the newly adult two-year-olds. 
The most favourable time for the assembling of corros is on 
those days when great heat and calm at midday is succeeded 
towards evening by an extra strong sea-breeze. On such occa- 
sions very large numbers will leave between sundown and dark. 
Northerly winds will almost absolutely arrest the exodus. 
For the season of 1900-1901 our game-books showed a total 
of 4849 wildfowl (4674 ducks and 175 geese)—a record for which 
we were good-humouredly taken to task by our venerable friend 
the late Canon Tristram, who thought it looked excessive. The 
figures certainly are big, but the next entry in the book reads :— 
March 15.—This evening between fifty and seventy corros left within 
half an hour—say 50,000 to 70,000 ducks. Next morning the marisma 
appeared as full as ever. 
Our toll of 5000 seemed by comparison but as a drop in the 
bucket ! 
