Black-billed Magpies can recognize humans
They are not much sensitive to smell so it is likely that they use vision to recognise.
Washington: Researchers from Seoul National University have added the Black-billed Magpie to the list of animals that are capable of recognising humans.
Their revelation is based on an "accidental" finding, wherein a research team member who climbed up tress to pick up eggs and chicks from Magpie’s nests for surveys was followed by the angry bird.
It emerged that the bird could recognise the man who was repeatedly breaking into her nest.
Researchers quickly designed a field experiment in which a pair of humans, a climber and one non-climber, wearing the same clothing was presented to magpies to see whether they showed selective responses.
The result was that all the tested magpies showed aggressive responses to the climbers only.
“It was very unusual thing. We`ve been doing exactly the same survey every year for more than 15 years but nobody was followed by birds. Then, what was so special about this one, unfortunate, crew member?” said Dr. Sang-im Lee, leader of the magpie survey team at Seoul National University.
Since birds like magpies are not that much sensitive to smell and the distance between the experimenters and the magpies was more than 10 meters, it is more likely that they use vision to recognise.
Furthermore, since the climber and the non-climber wore the same clothing and walked similarly in the experiment, the only distinguishing factor between the two humans is the face.