face 97 H Fig. 20 Hook branch: Chimpanzees of Bossou hooked branch overhead with stick hoot face Goodall Hoot face: pouted trumpeted lips that go with pant-hooting. The mouth may open completely or partially. hop bipedal on spot Nishida Jump bipedal. Juvenile male in courtship jumps in place in front of estrous female, to elicit her to present, or in front of adult female to harass her. Some juveniles jump up and down while pant-grunting vigorously in front of dominant male. Cf. leap bipedal and hop quadrupedal on spot. See video. hop quadrupedal on spot Hop repeatedly on four limbs on ground or on mothers back as solo play. Infant may hop while pant-grunting. Courtship by juvenile male. Also hop on branch, vegetation, bed, etc. as trampolining. Cf.