I've heard people joking about "gullnados" and how they fly in tornado formations when scavaging for food (supposedly). I have noticed that they seem to float in circles in the air, and I'm wondering if that really is because they're riding currents and trying to save energy? Thanks in advance for you time, hope my question is clear enough!

Yes that's right. Have a look at this website:

http://www.spwickstrom.com/gullfaq/