Domestication is generally assumed to have resulted in enhanced communication abilities between non-primate mammals and humans, although the number of species studied is very limited (e.g. cats, Felis catus; dogs, Canis familiaris; wolves, Canis lupus; goats, Capra hircus; horses, Equus caballus). In species without hands for pointing, gazing at humans when dealing with inaccessible food during an unsolvable task, and in particular gaze alternations between a human and the unsolvable task (considered forms of showing), are often interpreted as attempts at referential intentional communication. We report that kangaroos, marsupial mammals that have never been domesticated, actively gazed at an experimenter during an unsolvable problem task (10/11 kangaroos tested), thus challenging the notion that this behavior results from domestication. Nine of the ten kangaroos additionally showed gaze alternations between the unsolvable task and experimenter. We propose that the potential occurrence of these behaviors displayed towards humans has been underestimated, owing to a narrow focus on domestic animals, as well as a more general eutherian research bias.  

Video data were recorded during live observations of kangaroos (n = 11) during six training and one testing trial with an unsolvable task. Videos were analysed with BORIS v. 7.9.7 behavioural analysis software. The behaviours of six kangaroos were double coded by K.H.O and A.C.G. Behavioural observations including proportion of trial interacting with box and experimenter, and presence of gaze alternations between box and experimenter were exported to Microsoft Excel and statistically analysed with R Studio v.1.2.5042 using the 'tidyverse' package for data cleaning and visualisation, 'janitor' package for contingency tables, 'skimr' package for summary statistics.