Another possible explanation of the title might be the contrast between the beautiful setting of the African veldt (plain) and the bloody violence that occurred there. The fight between the Mau Mau and the British changed the landscape and beauty of Kenya so much that it is no longer recognizable. Africa is "a far cry" from what it was because it no longer resembles the Africa before civilization came and settled there.
This particular part of Kenya in Africa is nature at its most beautiful. Line 1 refers to "the tawny pelt of Africa", describing the brownish-orange colors found in the picturesque landscape. In line 4, the poet says, "Corpses are scattered through a paradise." The poet is telling us how the fighting between the British and Mau Mau has changed the scenery of the veldt. Instead of noticing the lustrous natural colors, we see blood and dead bodies. In lines 11-14, the poet again refers to the natural beauty of the land, the wildlife and beasts who used to rule there. He then compares the "natural law" that exists in the animal world to the senseless killing of mankind.
I hope this gives you another perspective on the meaning of the title.
The poem's title references the history of imperialism and colonization of Africa by other countries, particularly the British.
"Between this Africa and the English tongue I love?
Betray them both, or give back what they give?
How can I face such slaughter and be cool? How
can I turn from Africa and live?" (Walcott)
The poet speaks of the struggle between the white forces that rule Africa in this period and the uprising in the communities that attempted to free themselves from British domination.
"It is likely that Walcott's West Indian origins, linked back to part of his family's original homeland in Africa, and the domination of both his country and Kenya by Britain spurred him to take special note of events in Kenya"
That is why he wrote the poem, to chronicle the events occurring in Kenya, which were similar to those happening in other British colonies, which suggest that the cry for freedom from these nations echoed through and beyond the continent of Africa.
A shared struggle that deeply affected the poet who has both black and white ancestry.