This is a spotted sandpiper video.
This video from the USA says about itself:
A small flock of Least Sandpipers feeding. It was also at Cibola NWR, Arizona. Recorded by George Jameson.
This video says about itself:
A mixed flock of red-wings [see also here], great tailed grackles, yellow-headed blackbirds, and starlings flying at sunset. Recorded by George Jameson.
Yellow-headed blackbird photo: here.