In general, birds symbolize the presence of a higher being with a connection to the sky, ultimately freeing themselves from the restraints of gravity. Birds represent a human's power and ability to escape gravity and achieve success through the efforts of climbing higher and taking off into flight.
Specific breeds of birds can also symbolize personality and character traits as well. For example, a canary symbolizes the power of the voice, whereas a cardinal represents renewed vitality and a sense of self-importance. Doves represent peace, maternity, prophecy and feminine energies, whereas a heron symbolizes aggressiveness, self determination, self reliance and authority.