When European starlings are frightened by an aerial predator they fly in tight formation in a giant shimmering blob called a murmuration. If you’ve never seen it, check out these two examples: Murmurations in Lorain by Chad+Chris Saladin and Murmuration a 2011 film on Vimeo.
Starlings aren’t the only ones who fly like this. Shorebirds are masters at staying in formation, flying high and low and sweeping between the waves when threatened from above.
In the video below, a shorebird flock flashes black and white at Ocean Shores, Washington in November 2018. Their backs are dark, their bellies are white, so they change color as they turn in the air.
The flock is doing this for a reason.
Watch a predator dive in at the 0:13 time mark. It looks like a peregrine falcon to me. 🙂
(screenshot from video by Peggy Dolane on YouTube)
p.s. Starlings and sandpipers have other similarities. Back in 2008 I mused about starlings as “Land”pipers.