Although scientists have failed to find evidence of contagious yawning in tortoises (though those scientists succeeded in winning an Ig Nobel Prize), other scientists have now found evidence, they say, of contagious yawning in budgies [a non-yawning specimen of which is pictured here in a photo by Elektrofisch]. They published a study about it:
“Evidence for contagious behaviors in budgerigars (Melopsittacus undulatus): An observational study of yawning and stretching.” Michael L. Miller, Andrew C. Gallup , Andrea R. Vogel, Shannon M. Vicario, Anne B. Clark, Behavioural Processes, Volume 89, Issue 3, March 2012, pp. 264–270. The authors, at Binghamton University, Binghamton, NY, report:
“Yawning is contagious in humans and some non-human primates. If there are social functions to contagious behaviors, such as yawning, they might occur in other highly social vertebrates. To investigate this possibility, we conducted an observational study of yawning and an associated behavior, stretching, in budgerigars (Melopsittacus undulatus), a social, flock-living parrot…. This study provides the first detailed description of temporal patterns of yawning under social conditions in a flock-living species as well as the first support for contagious yawning and stretching in a non-primate species in a natural context. Experimental evidence will be necessary to confirm the extent of contagion in either behavior.”
(HT Dan Vergano)