POLITICAL REPRESSION and turmoil are often accompanied by an outbreak of literary activity, and the case of South Africa is no exception. Mating Birds, the first novel of Lewis Nkosi, a young Black South African writer, is a story set in and expressly concerned with the current political and social conditions of South Africa. It is short, clear, direct and intensely unforgiving--a cry from the heart, dedicated to "my grandmother, Esther Makatini, who washed white people's clothes so that I could learn to write."

Mating Birds

by Lewis Nkosi

Harper and Row; 184pp.; $5.95

One of the most striking features of Mating Birds is its simplicity. The plot is almost stereotypical, revolving around a sexual relationship between Ndi Sibiya, a Black man, and Veronica Slater, a white woman, for which Sibiya is tried, convicted and sentenced to death. The story is told in the first person by Sibiya in the few days before his execution. There are few characters, and they are hardly developed; even Sibiya seems largely just a symbol, a spokesman and martyr for all of South Africa's Blacks. And the essential subject of the novel remains from beginning to end the larger picture of life under apartheid.

In this narrow focus lie both the greatest weaknesses and strengths of Mating Birds. The novel begins, "In a few days I am to die," but the common 20th century technique of telling a story from the end is not carried off with particular novelty or innovation. So far as contemporary novels go, the plot is largely predictable. It follows the protagonist, Sibiya, from a Zula reservation to his enrollment in school, to expulsion after participation in anti-apartheid riots, to his progressive obsession with Veronica at a beach, to forbidden copulation in her bungalow, to discovery, trial and sentencing. There are few surprises in the novel, and certain scenes seem like clips from the evening news in America. Literary critics who concentrate on text at the expense of content would hardly be impressed.

What is missing in subtlety, however, is more than compensated for in power. Nkosi knows his strengths and utilizes them effectively. His tone is never affected or presumptuous but is always immediately understandable and often colorful and refreshingly poetic. He is writing about a world he knows first hand, as is clearly and beautifully evident in images such as those of the Zulu homeland. And the entire novel is suffused with the intensely emotional voice of a man who cares deeply about his country and who tries--and succeeds--in expressing that passion through his writing.

THE ESSENTIAL point of Mating Birds is that there really is only one story in South Africa, the story of injustice and pain. Nkosi shows us the possibility of a love story in the development of a human relationship between Sibiya and Veronica. All potential for tenderness and caring, however, is crushed by the brutally repressive system of apartheid.

Inequality is not only a political or an economic condition, but is also a terrible force that wreaks havoc on all facets of normal human life. Racism penetrates to the deepest levels of emotion, transforming even love into a blind, uncontrollable desire for sexual possession and ultimately into a crime punishable by death. Sibiya's greatest hope and Nkosi's greatest goal is to free the people of South Africa from this cruel tragedy; Mating Birds is so singleminded and blunt only because the emotion is so strong.

For his efforts, Lewis Nkosi has triumphed in his literary debut. The picture he paints of South African society is bleak and powerful and, in the end, convincing. The frustration and psychological suffering that apartheid imposes on all elements of life are made crushingly vivid, and the emotional impact of the unrestrained, passionate voice is compelling. Through this nightmare there remains a glimmer of hope in the freedom songs of the political prisoners, "a single powerful sound rolling and thundering, shaking the very foundations of the prison walls." It is not a practical agenda but only a vision of a possible future. Technically, it does not mesh well with the generally hopeless tone. But emotionally, it is the underlying credo of the entire novel: a new world will be--must be--born someday in South Africa.