Table 2.
Gesture and vocalisation types produced to initiate carries in chimpanzee mother–infant dyads identified in this and other studies on wild groups in Budongo (Hobaiter and Byrne 2011; Roberts et al. 2014a); Gombe (Goodall 1986) and Mahale (Nishida et al. 1999)
| Gesture/vocalisation | Definition (this study) | Used by | Budongo | Gombe | Mahale |
|---|---|---|---|---|---|
| Audible | |||||
| Loud scratch [ls] | Signaller makes deliberate scratching movements on own body | Mother | Big loud scratch | Self-scratch | Scratch self signalling |
| Slap ground [sg] | Signaller hits ground with flat palm of his hand | Mother | Slap object | Slap ground | Slap branch |
| Tactile | |||||
| Arm on [ao] | Signaller places palm on recipient’s back (>2 s) | Infant | Hand on | – | – |
| Shake back* [sb] | Signaller shakes lower back in an upward movement when recipient is already clinging | Mother | – | – | – |
| Scoop infant [rb] | Signaller reaches behind himself and gently pushes infant up onto back with a back ward and upward movement | Mother | Scoop | Scoop | Scoop infant |
| Touch [to] | Signaller makes short (>2 s) contact with recipient using palm and/or fingers | Both | Touch inner hand | Touch | Touch |
| Directed push [pu] | Signaller uses limbs or body to bring recipient in direction of movement | Mother | Directed push | Pull towards hand leading | Push ahead |
| Pull [pl] | Signaller moves recipient’s body part towards himself | Both | Pull | Pull | Pull |
| put ventral [pv] | Signaller pushes recipient in ventral region | Mother | – | – | Put ventral |
| Visual | |||||
| Backward sweep [bs] | Signaller stretches arm towards behind himself in a short, rapid movement | Mother | Backward sweep | Climb aboard | – |
| Extend leg [el] | Signaller extends leg to facilitate climb onto self | Mother | Present leg | – | Extend leg as ladder |
| Look [lo] | Signaller gazes at recipient (>2 s) | Both | Look | Wait | Look; wait |
| Lower back [lr] | Signaller, in lateral position to recipient, lowers abdomen without stopping locomotion | Mother | |||
| Stop and look back/down [lb/ld] | Signaller stops with body orientated in direction of movement and looks back (or down) at recipient | Both | – | – | Look back |
| Present back/shoulder/venter [pb, ps, pv] | Signaller offers back/venter to recipient | Mother | Present | Present | Present |
| Reach [ra] | Signaller extends arm towards recipient | Both | Reach | Extend hand | Extend hand |
| Rear up* [ru] | Signaller briefly rises straight up on two feet while positioned towards recipient | Mother | – | – | – |
| Turn Bipedal* [tb| | Signaller turns towards recipient with short bipedal movement | Mother | – | – | – |
| Vocalisations | |||||
| Hoo whimper [hoo] | Signaller utters a series of soft, low pitch sounds that may become progressively louder and higher in pitch | Infant | – | Whimper | Whimper |
| Soft grunt [sgr] | Signaller utters a soft, barely voiced sound | Mother | – | Soft grunt | Grunt |