This loon is coming in for a landing on a New Hampshire pond. This loon is an intruder, who is attempting to take over the territory of the pair of loons that make the pond there home.

Loons are very territorial, as their population has recovered in New England, territorial fights are again common.
The pair of loons that had a nest on the pond was able to drive the intruder off and went on to hatch two chicks.