Two legs are better than one
What about these prop roots, or stilt roots, which are also adventitious, aerial and structural? Are they just a nest for this heron? Take a look at the area around this mangrove, with its prop roots, and you'll find the answer. They are adapted to anchoring the tree in soil that is periodically, or constantly, flooded.
How else could the tree support itself in all the mud with nothing to hold on to? Without these roots, it might simply sink and topple over. Distributing its weight across many props makes the mangrove more stable than a "normal" tree could ever be. Just think – if the leaning Tower of Pisa looked like a mangrove, maybe it wouldn't be so crooked.
Rhizophora mangle
© Jardin botanique de Montréal (Normand Fleury)
© Jardin botanique de Montréal (Normand Fleury)