The mating season for herons seems to have been later this year. The parents seem to have taken off and have left their maturing offspring to look after the nests. Frankly, they are just hanging around on branches doing nothing except posing for photos - probably if they could use a cellphone they would be taking selfies...
Images taken hand held with Canon EOS 7D MkII, EF-L 100-400 Mk II + 1.4 Mk III extender.