I can do pretty good impressions of birds. Do you know about that? 
Can you do both bird calls and bird songs?
Yes I think I do both. What is the difference though exactly?
Bird vocalization
Bird vocalization includes both bird calls and bird songs. In non-technical use, bird songs are the bird sounds that are melodious to the human ear. In ornithology and birding, songs (relatively complex vocalizations) are distinguished by function from calls (relatively simple vocalizations).
Definition.
The distinction between songs and calls is based upon complexity, length, and context. Songs are longer and more complex and are associated with courtship and mating, while calls tend to serve such functions as alarms or
people there. I believe I can - I think I can establish, unless we - again, unless I run into something that I have not run into before–a good relationship and good feeling toward the United States ...FULBRIGHT: Do you know our Ambassador to India?GLUCK: I know John Sherman Cooper, the previous Ambassador.FULBRIGHT: Do you know who the Prime Minister of India is?GLUCK: Yes, but I can't pronounce his name.FULBRIGHT: Do you know who the Prime Minister of Ceylon is?GLUCK: His