Since the male is the first one at a nesting site I’m guessing that’s who this is.
This spot looks terrible for building a nest, no branches for support, just hanging in the air. However, it actually has been used for 3 years that I know of. The tree itself, surrounded by water, is important.
Most Heron nests look to be a big pile of sticks. They last every year (most do anyway) through storms regardless of how flimsy they appear.
Below is a wider view from further back.