eagles will destroy your drone

https://www.wsj.com/articles/bold-eagles-angry-birds-are-ripping-80-000-drones-out-of-the-sky-1506701429

"In his first 2½ years flying drones at the mine, Mr. Steven said he lost 12 drones to eagle attacks, which cost his employer, South Africa-based Gold Fields Ltd. , some $210,000. During the past year, when he focused his flying in the morning, he has lost two—with two more close calls.
​​Any successes at deterring wedge-tailed eagle attacks in Australia could provide clues in how to minimize avian obstacles in other regions."

I haven't had any bird interested in my quadcopter yet.  Hopefully it won't happen.