LEAD POISONING IN WATERFOWL. 6 
SPECIES OF BIRDS AFFECTED. 
The list of species of birds at present known to have been poisoned 
by eating shot is small, but it will undoubtedly be increased when 
the facts are better known. In the following brief list all but one 
species (the canvas-back) are included from personal observations of 
the writer: 
Mallard (Anas platyrliynclia) . 
Pintail (Dafila acuta tzitzihoa). 
Canvas-back (Marila valisneria) . 
Whistling swan (Olor columbianus) . 
Marbled godwit (Limosa fedoa). 
Lead poisoning is a common affection in all these except the 
marbled godwit. Only one specimen of this bird that had died from 
eating shot has been examined. In this species and in other shore- 
birds lead poisoning is probably rare. Geese and several species of 
ducks in addition to those listed above are said to have been affected 
in various localities, in particular on Back Bay, Va., but these re- 
jDorts have not as yet been investigated. 
As has been stated, the shot secured are taken while feeding. Pin- 
tails and mallards delight in working in shallow water, where they 
dig away the mud to a depth of 6 to 18 inches, in search of succulent 
roots and tubers. In this manner they work over extensive areas, 
forming " duck holes " from 1 to 15 feet or more in diameter. Swans 
feed in much the same manner, but, with their long necks, are en- 
abled to work in deeper water. The canvas-back is a diving species 
that digs constantly in the bottom mud and frequently feeds at a 
considerable depth. With all these birds certain quantities of gravel 
or grit of some kind are necessary for the proper grinding, or trit- 
uration, of food in the gizzard to put it in proper form for the ex- 
traction of nutriment. In the mud of marshes and lowland lakes 
little gravel is present, and to secure this needed element the birds 
in feeding develop a tendency to swallow any small, hard object 
they encounter. In this way the shot that have accumulated about 
shooting points are swallowed one by one. The bird may be several 
days or even longer in securing a fatal dose or it may pick up a 
large number of pellets at one time. In either case the shot are 
held in the gizzard to be slowly ground away, only small particles 
of lead passing on into the intestine. 
SYMPTOMS OF LEAD POISONING. 
The. symptoms of lead poisoning as observed in waterfowl are 
similar in many ways to those found in mammals. A prominent in- 
dication of this malady is a paralysis of important muscles, which 
increases steadily as the ailment progresses. This paralysis seems 
first to affect the nerves supplying the great pectoral muscles of the 
