Cliff Swallows engaging in copulation - may be an attack from a male attempting an extra pair copulation

St. Louis

 

A few articles on cliff swallow behavior, particularly this extra pair copulation:

 

www.10000birds.com/why-do-cliff-swallows-flutter-their-wi...

 

thebirdersreport.com/wild-birds/bird-sightings/cliff-swal...

Done