救助受伤乌鸦的女子持续收到鸟类"谢礼" [video]
Woman who rescued injured crow keeps getting 'thank-you gifts' from birds [video]
一名女子救助了一只受伤的乌鸦，此后不断收到鸟类送来的"谢礼"。发帖者也分享了自己救助山雀幼鸟、用糖水救活三只大黄蜂的经历，这些动物康复后会飞回来悬停、点头致意。帖主正在寻找研究这类动物报恩行为的文献或书籍。
Birds are wild. Found a chickadee fledgling in the road earlier this year and nursed him for a couple days before we found a legitimate rehab. Little guy would just hop out of his box, perch on your finger, and sing as loud as he could until you fed him scrambled eggs. Really got me thinking about how special birds are. We have a hummingbird that visits and he'll do stuff like fly into the garage if the door is open, hover and stare at you for 1-2 seconds, and then take off. It's happened so many times I've stopped being startled by the sudden brrrr noise you hear from their wings flapping (they're so fast they can show up in the blink of an eye).
The bumblebees do something similar (I've oddly nursed three different bees with sugar water—all just happened to be in my field of vision crawling around on the ground but not flying). Now you get a bumble or two per day checking in with a quick hover and bob kind of movement before shooting off into the distance.
Does anyone know of any research into this or books identifying behavior like this?
来源：Hacker News · 首页 · news.ycombinator.com