Sunsets in Lancaster County, Pennsylvania are looking mighty fine this week as thousands of birds take to the sky. According to ornithologist Bob Schutsky, the birds in the clip are likely a combination of common grackles, red-winged blackbirds, brown-headed cowbirds and European starlings. 

We've seen out fair share of avian swarms, known as murmurations, but this one is arguably one of the biggest! "This type of mass-motion, wave behaviour, or boil, is often observed when there is a raptor in the sky in pursuit of prey — the prey being a blackbird,” Schutsky tells Lancaster Online

Like schooling fish, birds' odds are improved when flying in a group. The ever-changing pattern of the avian "wave" can confuse predators, as it makes it difficult to single one animal out.

Check out this murmuration shot in the Netherlands last year. Following a single bird with your eyes is nearly impossible! 


How do they know where to fly? The rules are fairly simple: if a bird next to you moves, you move. Watch the full video:

starling murmuration-related-2015-10-26

 Top header image: Ken Yasuhara, Flickr