Egrets often like to stay together, as this photo below shows, all swooping in together to land and then begin to fish.
but sometimes there is competition in these same fishing grounds, with birds fighting for dominance, as in this sequence of photos below.
And why are they white....?
Large wading birds have few predators, so crypsis (our word for today, and this means the ability of an organism to conceal itself especially from a predator by having a color, pattern, and shape that allows it to blend into the surrounding environment)is important only to reduce their visibility to their prey.
Being white below is the best colour to avoid being detected by aquatic prey. This has been shown experimentally: fish are more likely to occur close to a model bird that is white below than one that is dark below. Remember that next time you go fishing.....