The video IDs the bird as an Australian Magpie, and we have to admit that this is a very magpie thing to do:
By Garrison Frost
November 23, 2013
A New Colony of Caspian Tern Decoys on Aramburu Island
Richardson Bay Audubon Center is attacting breeding pairs of Caspian Terns with these newly painted tern decoys—a strategy successfully used by previous tern relocation efforts.