22 BULLETIN 672, U. S. DEPARTMENT OF AGRICULTURE. 
pens would be hard to move, as mud and vegetable matter gather in 
the water at the lower end and hold firmly. 
In regions where artesian wells are utilized for water, posts may 
be set in the ground to form frameworks for the pens. The top 
should be covered, otherwise birds still unable to fly may clamber 
out and escape, only to die in the grass and rushes. Where pens are 
fixed permanently they should not be too large. As birds recover 
they begin to fly about and in large pens are liable to injury from 
striking the wires. It is very difficult to capture and handle ducks 
properly in large inclosures. The dimensions given above are con- 
sidered best, though stationary pens may be built in the form of an 
ell, each arm of which is 12 feet long. 
In gathering sick birds it is a good plan to have two men work 
together. As the ducks are picked up they should be laid in a single 
layer in the bottom of the boat and covered lightly with rushes. On 
hot days it is well to sprinkle the rushes with water to aid in keeping 
the birds cool. If birds are left unshaded the intense heat of the sun 
will kill many, and they are more readily handled if covered, as then 
they imagine themselves hidden. 
It is necessary to tie active birds in order to keep them in the boat. 
A soft cotton twine (16-ply) has been found best suited for this pur- 
pose. Twines that are hard or too small in size cut the skin and 
cause discomfort. In tying a duck a loop is thrown around the 
large bone of either wing near the body and carried across the back. 
This is tied behind tightly enough to hold the two elbows in position 
on either side, but not to draw them together behind (PL III, fig. 2). 
In tying the feet, cross them and wrap the string around them twice, 
and then tie tight enough to hold but not to cut off the blood supply. 
If the second knot is made a slip knot in each case, as shown in the 
illustration, the birds may be released readily when desired. 
Before placing the ducks in the pens (PL IV, fig. 1), each one, if 
possible, should receive a dose of castor oil, This cleans out the 
intestinal tract in a short time and aids in alleviating the irritation 
due to the alkali. The purgative may be administered readily with 
a medicine dropper, the glass portion of which is 3h inches long. The 
duck's bill is held open, and the dropper, filled with castor oil, is 
inserted well down the gullet past the opening of the windpipe. The 
bulb is then pressed, the dropper quickly withdrawn, and the bill 
allowed to close in order that the bird may swallow. The head 
should be held up for an instant. For teal, one dose (about 1 c. c.) 
is sufficient. Other ducks should receive two dropperfuls (about 
2 c. c). The ducks may then be placed in the pens. 
Teal must be separated from the larger species in confining sick 
birds or many will be killed, though spoonbills and teal may be kept 
together without injury. Weaker birds, in addition, must be kept 
