38 
ANAS BOSCHAS 
Millais (1902) has called attention to the fact that the agents most dangerous to 
the eggs and young are the Carrion and the Hooded Crows, who cause greater havoc 
than all other vermin put together. This I believe is absolutely true. He says he 
has also found whole families massacred by stoats (or other vermin). Naumann 
(1896-1905) who has gone into this question in some detail, gives a long list of 
predatory mammals, fish and birds that are known enemies of the Mallard in west- 
ern Europe. This list includes various species of hawks {Circus ceruginosus, C. pygar- 
gus, C. cyaneus), falcons, crows, ravens, magpies and eagles, foxes, martens, pole- 
cats, weasels, otters, rats, pike and possibly even frogs. 
The Mallard is also subject to the attacks of various parasites. Cysts of Psoros- 
perviia have been found, chiefly in the muscles of the breast (Hagen, 1880) and 
Corbin (1873) tells of a three-fourths grown Mallard found in a dying state with a 
leech in its mouth. Various feather mites and intestinal worms of nineteen different 
species are given by Naumann (1896-1905) as parasites afflicting the Mallard. 
Damage. In our own West migratory Mallards do not appear in large numbers 
until the crops are harvested, and local birds are scarcely numerous enough to do 
much damage. In parts of our Southwest, however, certain grain farmers have 
received permission from the U.S. Biological Survey to shoot ducks that are damag- 
ing their crops. The rice farmers of Arkansas and the Sacramento Valley in Cali- 
fornia have suffered most. It was estimated that in the autumn of 1917, when the 
rice harvest was delayed, about $35,000 worth of grain was destroyed near De Witt 
and Stuttgart, Arkansas (McAtee, 1918). In the Imperial Valley (southern Califor- 
nia) after the water is turned on to the fields in midwinter to sprout the seed-grain, 
vast numbers of Mallards and other ducks appear, presumably from farther west, 
and are said to do some damage. 
In Ireland they have been reported as being very destruetive to ripening corn 
(Ussher and Warren, 1900). Naumann (1896-1905) speaks of similar habits in 
Germany. They have been reported as also feeding on sprouting grain, but the 
damage is probably never serious. 
Food Value. The flesh of the Mallard is generally as excellent as that of any 
other species, but it is never on a par with that of the Red-head, Canvas-back or 
American Widgeon when those superlative fowl are shot under the most favorable 
conditions. Naturally the quality of the Mallard’s flesh varies greatly, depending 
upon the amount of fat which has been accumulated, partlj' on the age of the bird, 
and partly on the proportion and kind of vegetable matter consumed. In the spring 
and summer the birds are far less palatable than in autumn, when, after they have 
assumed their full plumage, they begin to gain condition, and lay on a reserve of 
fatty tissue. When feeding on wild rice or grain left on the stubble fields they become 
