Final answer:
There is no specified number of mammal species mentioned in the provided references that Homo erectus exploited at Choukoutien. However, evidence suggests an increase in meat consumption by early Homo species.
Step-by-step explanation:
The question pertains to the number of mammal species exploited by Homo erectus at the site known as Choukoutien (also spelled Zhoukoudian). Evidence found at Zhoukoudian, such as ancient hearths, charcoal, and charred animal bones, indicates that H. erectus there was hunting, cooking, and consuming meat. There is no specific number of mammal species mentioned in the provided references that Homo erectus exploited at this particular site. Therefore, the direct answer to the student's question regarding the number of species cannot be provided based on the available evidence. However, it is important to note that an increase in meat consumption is suggested by archaeological findings such as the KNM ER 1808 specimen from Koobi Fora, which implies a shift toward carnivory in the diet of early Homo species. Yet, the effects of hunting by H. erectus on mammalian biodiversity at the site cannot be quantified with the given data.