What happens when Helmeted Guinea Fowl, out walking, encounter an unexpected pothole? Do they fall over? That depends, in quite an improbable way, on whether they see it coming or not …
In 2005, a research team at Concord Field Station, the Museum of Comparative Zoology, Harvard University, US, endeavoured to clarify things by encouraging Guinea Fowl [* see note below] to walk along a raised platform which had a hidden drop covered with a fragile layer of stretched tissue paper. With potentially counter-intuitive results. When the birds couldn’t see the drop, hardly any stumbled, but when they could (tissue paper removed) quite a few of them did.
“Our results show that, despite altered body dynamics and a great deal of variability in the response, guinea fowl are quite successful in maintaining dynamic stability, as they stumbled only once (without falling) in the 19 unexpected perturbations. In contrast, when the birds could see the upcoming drop in terrain, they stumbled in 4 of 20 trials (20%, falling twice), and came to a complete stop in an additional 6 cases (30%).”
Full details can be found here in : ‘Running over rough terrain: guinea fowl maintain dynamic stability despite a large unexpected change in substrate height’ by Monica A. Daley, James R. Usherwood, Gladys Felix and Andrew A. Biewener, January 1, 2006, Journal of Experimental Biology, 209, 171-187.
Additionally, the authors provide several slow-motion videos [all in .avi format] showing the birds very successfully negotiating the unexpected potholes: here: here and here. And not quite so successfully here. [*note: With a broom - visible at the end]
BONUS : A video in which the paper’s lead author (and Chicken of The Future participant) Dr. Monica Daley, HBSc MA PhD PGCAP FHEA, provides ‘some observations on leg control for running from experimental data on ground birds’. (the pothole clip features at around 10:15)