Why use the guineafowl to represent colonialism and postcolonialism?
Names of places often conceal a colonial history. "Guinea" is the name, or part of the name, of several former colonies. The following web page, The Many Meanings of "Guinea" traces the history and geography of the word.
In Afrikaans the guineafowl is called a "tarentaal", from Terra Natal, a description given to the southern African interior by early settlers. Hence, the bird or chicken of Terra Natal.