On my last trip to Bolivar Flats, the willets were in fighting mode with breeding season in full swing. While taking photos of avocets, the willets were squawking away and chasing each other around. These two started going at it and were circling around after one grabbed the others neck. He then lifted off trying to get away but the other one held on for a while. He finally broke free and left the area.
Taken with Canon 1DX and Canon 500mm F4 IS II with 1.4X III teleconverter mounted on Skimmer ground pod with Wimberley II gimbal head.
Aperture priority, 1/1000 sec @F 7.1, ISO 1600, evaluative metering, + 1 1/3 exposure compensation