112 MIGRATORY SPRING FLIGHT. 
upon the surrounding ice, lave their burning feet and 
cool their thirsty throats rendered dry by their rapid 
travel. 
The heat and dryness which attack migratory birds 
when high in the air, during a long flight, are so 
well known by handlers of carrier pigeons that they 
often moisten the birds’ feet in cool vinegar, before 
flying them, to prevent their stopping at watering 
places to cool themselves, thereby averting danger 
and keeping notes attached to the homers’ bodies 
or tail quills dry and safe. 
In the case of a quick freeze, where sheets of water 
have been suddenly covered with ice, ducks will 
alight in large numbers in the middle, and by their 
weight depress the ice in the center so water will flow 
toward them from weed-holes or cracks existing upon 
the surface, thereby obtaining water by cooperation 
where singly they would assuredly fail. 
A short stop and away to the northward, diverging 
their flight—according to the proportion of water— 
until they reach the goal their scouts have already 
explored. They quickly find out their accustomed 
feeding grounds, and it is astonishing to observe with 
what infallible skill they detect and know to a cer- 
tainty whether a corn field has been shucked or not; 
one can always tell strangers from local birds by the 
feet and bills of the former being clean, whereas, those 
of the local birds upon their return to the water are 
soiled from the mud of our fields or prairies. They 
quickly arrange their various grounds and settle down. 
These flights continue for several days, pintails as 
a rule leading, mallards coming next, followed by the 
greenwinged teal. A great many pass over high in 
