<Tr> <Th_colspan="2"> Scientific classification </Th> </Tr> <Tr> <Td> Kingdom: </Td> <Td> Animalia </Td> </Tr> <Tr> <Td> Phylum: </Td> <Td> Chordata </Td> </Tr> <Tr> <Td> Class: </Td> <Td> Mammalia </Td> </Tr>

List at least three factors essential to the study of primate ecology