PUGNACITY IN CAPTIVE BIRDS
1. Most species do more or less competitive fighting for nesting sites or mates, especially:
Gallinaceous birds,—many of which fight furiously for mates;
The Ruff, or Fighting Snipe (Machetes pugnax),—very pugnacious for mates;
House Sparrows (Passer domesticus) fight for nesting places and mates; and
Some Waterfowl, especially swans and geese, fight for nesting places.
2. Most species which do not depend chiefly upon concealment, fight fiercely in defense of nests or young. Typical examples are:
Geese;
Swans;
The larger Flycatchers;