In order to determine if use of green flushes following fire varied among ungulate species, six common species of the Serengeti Ecosystem were censused on burned and in adjacent unburned sites. Thomson's gazelle (Gazella thomsonii Günther), impala (Aepyceros melampus (Lichtenstein)), Grant's gazelle (Gazella granti Brooke) and wildebeest (Connochaetes taurinus Thomas) were more abundant in green flush sites compared to unburned controls. No significant difference was found in topi (Damaliscus korrigum (Matschie)) and zebra (Equus burchelli Gray) between burned and unburned sites. Preference (differential use) for burned sites was negatively related to average ungulate body size across species. It is hypothesized that larger species (e.g. topi and zebra) try to maximize their energy and nutrient intake by feeding on both burned sites where there is a low quantity of high-quality forage, and unburned sites where forage quantity is high but forage quality is low. Smaller species (e.g. gazelles and impala) feed exclusively in burned sites (where there is higher quality forage) to fulfill the high metabolic requirements associated with small body-sized animals.