Exhibiting a distinct lack of care towards a negative situation. Behaving with reckless intent. Synonymous with tomfoolery, shenanigans etc.
Originating from a photograph taken of a seagull post falcon attack. The falcon had removed the neck of the seagull leaving only a bloodied spine. To which the seagull stood up and continued on as if its neck were still in place.
"Stop all this seagullery you lot!"
"I heard that he jumped off a bridge?"
"Yeah man, he was showing some serious seagullery that night."