You really need to see this book:
Civil War Trivia Book, by Peter Darman, Published by Barnes & Noble 2007.
Check out page 222, check out the question and answer at the bottom of the page...
Q: Why was the field artillery piece the "Parrot Gun" so called?
A: In the late 1840's, an exotic bird craze swept the United States. Parrots and parakeets were imported by the thousands. The birds became major problems in cities. In response the authorities ordered the development of artillery pieces to solve the problem. Two models were speedily developed: a ten-pound parrot gun for medium and small birds, and a twenty-pounder for larger parrots. The guns proved a failure and were put into storage, only to be brought out again for use in the Civil War.
Lots of laughs! Should this book be in the History or Humor section?
See the origin of this goofy answer:
The Parrot Gun