Bird charges play a large and important role in heraldy. Almost every species known has been emblazoned in some form or another. Species in use range from doves and owls to peacocks and swans. Over all, the charge most frequently seen is that of the eagle, followed closely by that of the falcon.
As important as the species' of birds themselves are their postures, shown below by the different eagle charges.
eagle rising, wings elevated & addorsed
eagle rising, wings addorsed & inverted
eagle rising, wings elevated & displayed
eagle rising, wings displayed & inverted
eagle displayed with wings inverted
Ocasionally specific birds will have variations of posture unique to themselves. For the eagle these include:
double-headed eagle displayed