Please answer the following question: In the sub-Saharan African country of Nigeria, there are two main species that tend to travel in groups. The antelope tend to travel in groups in high numbers, and thus exhibit a high density. Meanwhile, the bison tend to travel in groups of small numbers, and therefore exhibit low density. Both the antelope and the bison have natural predators that exist in Nigeria. Given the paragraph above, please answer correctly the following question: Individuals from which species, the antelope or the bison, will have lower rates of predator vigilance behavior?
A:
the antelope