This gallery is an encounter between 2 White-tailed Kites at Shoreline Lake Park in Mountain View. The kites flew around for several minutes with their legs dangling straight down, flying very slowly near each other while continuously calling. They circled each other cautiously as they gained altitude before coming together with talons extended out over the lake. This happened twice and one of the times they fell quite a distance towards the surface of the lake before separating. Was it a mating behavior or a territorial dispute? I certainly don't know for sure but it seemed less "aggressive" than an encounter I photographed at Arastradero Preserve in Palo Alto that was definitely a territorial dispute. Please note that I had to include several out-of-focus images in order to help fully illustrate the encounter.

The link below describes similar behavior in White-tailed Kites (referred to in the link as Black-shouldered Kites, their name at the time). I took the terms "leg dangling" and "flutter flight" from that document.

http://elibrary.unm.edu/sora/wb/v23n02/p0081-p0083.pdf