The images show vibrissa position in an attempt to contact the target platform during a single trial.
From the nature.com
We found that the occlusion of a single penetrating arteriole was sufficient to disrupt the vibrissa column and abolish the processing of cortical input.
From the nature.com
It has finely blotched yellow-green plumage, a distinct facial disc of sensory, vibrissa-like feathers, a large grey beak, short legs, large feet, and wings and a tail of relatively short length.