This document discusses the Rucervus genus of deer. It describes the two species, R. duvaucelii and R. eldii, and their subspecies. The document outlines the habitats and biomes of Rucervus deer, including grasslands, forests, swamps and marshes. It also discusses their competition with other animals like antelopes, and their evolution from the Cervus family through adaptive radiation of traits like antlers, fat deposits and fur patterns. The ecosystem succession in the grasslands is summarized from early colonization to the climax stage that allows animals like Rucervus to thrive.