Primates
Numero: 10.1007/s10329-024-01127-7
Data pubblicazione: 20/04/2024

Autori:

Nome: alice
Cognome: galotti
Affiliazione: Università di Pisa

Nome: giu lia
Cognome: fausti
Affiliazione: Università di Pisa

Nome: grazia
Cognome: casetta
Affiliazione: Università di Pisa

Nome: Andrea Paolo
Cognome: Nolfo
Affiliazione: Università di Pisa

Nome: veronica
Cognome: maglieri
Affiliazione: Università di Pisa

Nome: elisabetta
Cognome: palagi
Affiliazione: Università di Pisa


Abstract: In the last decade, increasing attention has been devoted to exploring some aspects of yawning in non-human animals. With their chin red mark, bony paranasal swellings, male large brains and long canines, drills (Mandrillus leucophaeus) ofer a robust model for testing hypotheses on the phenomenon. We identifed two yawn variants (covered, YCT and uncovered teeth, YUCT) which difer in terms of recruitment of muscular action units (AUs). We tested the efects of several variables (sex, dominance rank, context) on the duration of the yawn and the probability of YCT or YUCT occurrence. We found that males performed longer and more YUCT than females. These fndings support the Brain Cooling Hypothesis suggesting that those species showing large brains tend to display la rger and longer yawns. We also tested the State Changing Hypothesis predicting the presence of a temporal association of yawning and ongoing behavioral transitions. A sequential analysis revealed that after 30 s following a yawn, drills were signifcantly more likely to change their behavioral state. Through the observation of yawning, conspecifcs might gain knowledge of impending state changes. Seeing other’s yawns increased the probability of a similar response in the observers, thus suggesting the presence of yawn contagion in drills. Although the dataset needs to be expanded, our fndings indicate that yawning is variable in drills, it can be associated with subjects’ state changes, and the imminent shifts can be perceived/processed by conspecifcs
Indirizzo: https://www.researchgate.net/publication/380004668_More_than_a_simple_fxed_action_pattern_Yawning_in_drills