Is this bird circling behavior normal?

Observation by Susan Tessier, with help from Jackie Schaeffer:

Video shows birds swimming in circles. Sometimes this is normal behavior.

LEO Network says:

Thank you Susan for sharing this video. One of the common observations with wild birds infected with Highly Pathogenic Avian Influenza (HPAI) or bird flu is an unusual circling behavior. But circling behavior is normal for some species, and differentiating between the two is helpful, given the heightened awareness about HPAI. LEO Network reached out to our friends at USGS and USFWS to help with identification of the species and comment on this type of behavior. Mike Brubaker

Comment by Andy Ramey:

This video appears to show two shorebirds commonly referred to as red-necked phalaropes (Phalaropus lobatus). Phalaropes feed by picking food items from the top of the water column (near the surface). These birds sometimes rapidly swim in tight circles to create upwelling with their lobed feet. This behavior may lift food items to the surface thereby facilitating feeding. Based upon my prior observations, and the extensive description of this behavior in the scientific literature, I would personally consider this observation to likely represent a completely normal behavior for this particular species. That stated, I am extremely appreciative for the vigilance of the observer that submitted this report and encourage future reports of similar circling behavior if/when observed in other (non-phalarope) species.