2. Contextual Variation in Chimpanzee Pant Hoots and its Implications for Referential Communication Hugh Notman¹ Biological Anthropology Athabasca University Drew Rendall² Department of Psychology University of Lethbridge

3. The “referential” paradigm Call structure is arbitrary with respect to referent Call structure is arbitrary with respect to referent Receivers attending to acoustic structure for cues to context Receivers attending to acoustic structure for cues to context Information-transfer function Information-transfer function “Semantic” utterances? “Semantic” utterances? Photo: Cheney & Seyfarth

4. Photo: Roger Fouts “Next of Kin”

5. = 1. Referential Model

6. = 2. Syntactical Model

7. Shortcomings of referential and syntax models Assumes caller and receiver attend to the same referent(s) Assumes caller and receiver attend to the same referent(s) Syntax model ignores function of calls used singularly Syntax model ignores function of calls used singularly Problems assigning context to calls: assumes static link between call and context Problems assigning context to calls: assumes static link between call and context

8. Notman and Rendall 2005. Animal Behaviour, 70, 177-190. Analyzed chimpanzee pant hoots from Budongo forest, Uganda Analyzed chimpanzee pant hoots from Budongo forest, Uganda 201 calls from 7 males 201 calls from 7 males INDIVIDUAL MALE AGE CLASS NUMBER OF CALLS JmAdult31 MuAdult36 DnAdult30 BkAdult33 Nk Young adult 25 Zf 30 MaAdult16 TOTAL201

9. Pant Hoots

10. Results summary Most salient variation in chimpanzee pant hoots is between individuals, not contexts. Most salient variation in chimpanzee pant hoots is between individuals, not contexts. Pant hoots show structural differences between “travel” and “non-travel” contexts Pant hoots show structural differences between “travel” and “non-travel” contexts

11. Results summary Most salient variation in chimpanzee pant hoots is between individuals, not contexts. Most salient variation in chimpanzee pant hoots is between individuals, not contexts. Pant hoots show structural differences between “travel” and “non-travel” contexts Pant hoots show structural differences between “travel” and “non-travel” contexts

12. Travel Arrive at food Rest

13. “Travel” Pant Hoot (ground)

14. Resting (tree)

15. Subtle structural differences evident between some contexts reflect different effects on vocal production introduced by variable arousal and the physical demands on vocal effort associated with calling in those contexts. Subtle structural differences evident between some contexts reflect different effects on vocal production introduced by variable arousal and the physical demands on vocal effort associated with calling in those contexts. This, in part, dependent on elevation of caller, social circumstance (arriving at food, looking to join others, etc) and physical activity (running/walking/resting) of caller. This, in part, dependent on elevation of caller, social circumstance (arriving at food, looking to join others, etc) and physical activity (running/walking/resting) of caller. Ie., source of variation incidental to caller activity Ie., source of variation incidental to caller activity

16. 3. “Embedded context” model Ground vs. tree Location in range Knowledge of area resources Direction of travel (if >1 call) Current social relationship

17. Implications for referential communication Any referential function for pant hoots likely based in mechanisms involved in the inferential abilities on the part of listeners Any referential function for pant hoots likely based in mechanisms involved in the inferential abilities on the part of listeners NOT mechanisms underlying the production of referential contrasts in callers NOT mechanisms underlying the production of referential contrasts in callers This “production/comprehension” asymmetry also evident in signaling systems of other animals AND in language trained apes. This “production/comprehension” asymmetry also evident in signaling systems of other animals AND in language trained apes.

18. Advantages of embedded context model Helps explain lack of contextual specificity (as well as inconsistent receiver response) to specific call types Helps explain lack of contextual specificity (as well as inconsistent receiver response) to specific call types A more “holistic” approach to understanding communication (involves dimensions associated with acoustic structure, receiver perception and cognition as it relates to prior knowledge and experience). A more “holistic” approach to understanding communication (involves dimensions associated with acoustic structure, receiver perception and cognition as it relates to prior knowledge and experience).

19. Implications for language…?

20. Acknowledgements Natural Sciences and Engineering Research Council of Canada (NSERC) Natural Sciences and Engineering Research Council of Canada (NSERC) University of Calgary University of Calgary Calgary Zoo Calgary Zoo The Budongo Forest Project The Budongo Forest Project Drew Rendall; Mary Pavelka; Vernon Reynolds; John Vokey. Drew Rendall; Mary Pavelka; Vernon Reynolds; John Vokey.