"Hirundo Nigricans" is a scientific name for a bird that is commonly known as the Black Martin. This species of bird is predominantly found in Africa, and its appearance is predominantly black with noticeable white patches around the beak and on its legs. Other synonyms for the Black Martin include the African Black Martin, the Black Saw-wing, and the Black-mantled Martin. These synonyms are used interchangeably to denote the same bird species. In essence, they describe the physical characteristics, behavior and habitat of this particular bird. Therefore, when looking for information on the black martin or hirundo nigricans, these synonyms can be used in scientific papers, books, and other literature.