http://www.forbes.com/sites/alexknapp/2013/05/14/lifelike-robotic-bird-got-attacked-by-a-hawk/

You know you’ve built a pretty good robot when nature itself has
been fooled. And a group of robotics researchers at the University of Maryland
got that compliment last month, when their robotic bird, dubbed “Robo Raven” was
attacked by a hawk.

Thanks to Russ Brown