In the midst of all this killing, there's a very interesting economic subtext that has a lot to do with where the poem actually takes place. On a geographic level, we're in the Caribbean – Haiti and the Dominican Republic, which share a much-bloodied border. But on a smaller level, the poem takes place in two locations that showcase a division of wealth that is very important to the piece: the Dominican dictator's palace and his sugarcane fields. The parrot, which we parsed out in the "Symbols, Imagery, and Wordplay" section, is hanging out in the palace, along with the dictator, Trujillo. It's all about the wealth there. And outside, slaving in the fields, are the Haitians who will eventually meet their demise at Trujillo's hands. The division between the rich and the poor, in this poem and in the actual historical event, occasion the massacre itself in many ways (it's not the whole story, but it's a good chunk of it).
The stark contrast between the rich and the poor in "Parsley" serves to add socioeconomic and political depth to the nature and cause of the Parsley Massacre.
The parrot in "Parsley," in addition to being a symbol for beauty, also highlights a prodigal dictatorship – unfeeling, and willing to spend money only on itself.