字幕表 動画を再生する 英語字幕をプリント Do you ever watching birds swooping around your car on the highway and think those things are daredevils. Look! They are playing with us. Definitely not doing that though, they are freaking out because they almost died. Hey everyone, thanks for watching Dnews today. I am Trace. As my old buddy Anthony used to say, "Birds are weird." There's nothing worse than sitting in your house and hearing the smack of the bird hitting the window. Last time it happened to me, there was a moment of fear, then a realization of what really happened, and then sadness and pity for the poor little robin that hit the window. There's a lot of feels here. Now I've recovered though, I am kind of angry. Cause, what's up bird? Can't you figure this out? Real talk: Nah, they actually can't figure this out. Each year, as many as 340 million birds smash into cars, and over 10,000 hit airplanes in 2013 alone. Building windows claims another 100 million every year. There's two things afoot here. Cornell's Laboratory of Ornithology says scientists believe birds hit windows because they think it's a hole in the building. Birds, like many animals, can't really understand reflections. so when they see trees and sky reflected in a window on a house, they believe it to be a tunnel through which they can see the other side. Birds, especially those attempting to escape from predators, will fly into the glass trying to get to safety. In fact, most animals can't recognize themselves in a mirror. The only known species to be able to do so are humans and some great apes, and perhaps dolphins, elephants and magpies. Cause there's no coincidence that these are also some of the most intelligent species around. When an animal like a cat sees a reflection, they don't smell another animal, so they know somethings up. But reflection in general are pretty confounding for most creatures. For birds though, cars and airplanes are a whole other problem. But the problem is more than just the birds being in the wrong place at the wrong time Birds fly fast, but they're kind of slow in the head. Based on a comprehensive analysis published last year in the Journal of Wildlife Management it appears that the speed of our transportation network is what claims the lives of millions of birds every year. A study in the Proceedings of the Royal Society B found that animal-vehicle collisions occur as vehicle speeds increase because of the way birds look for predators and other threats. Note that they only used the brown-headed cowbird. But they found that as the birds flew toward a video of an oncoming car, it initiated escape behavior at a specific distance from the threat. They figured bird brains are calculating the distance to the threat and not necessarily the time before they impact it. Thus, when the car speed increased, the birds couldn't get out of the way. When speed were low, less than 40 miles an hour, birds were mostly fine but once they exceed 74 miles an hour, the birds were pretty much screwed. Thinking about it this way, it's incredible that any bird can dodge an airplane accelerating to 160 or more during the takeoff, like 747 has to. As I mentioned, most birds aren't able to recognize window reflections. In the spring, male birds often swoop in to attack windows because they believe the bird they see in the reflection is encroaching on their breeding grounds. Penn states says this is the most commonly seen in mockingbirds, robins, and cardinals. And usually stops once they find the mate. so if your're annoyed, you should go be that bird's wing man, get it? Have you ever been in a car when the bird hits? Let us know down in the comments, and let us know what you did about it. There are a lot of different ways to handle it, but don't go grabbing the birds. That's usually bad. Make sure you subscribe more Dnews, thanks for watching.