Die reier is 50 tot 60 cm lank en weeg 280 tot 380 gram. Dit verskil van die Rooikeelreier deurdat hy ‘n bonkiger, heeltemal donker reier met donker bene en heldergeel pote is. Hy het die sonderlinge gewoonte om sy vlerke oop te sprei soos ‘n sambreel om ‘n skaduwee te vorm wanneer hy visvang.
The black heron is a medium-sized (42.5–66 cm in height), black-plumaged heron with black bill, lores, legs and yellow feet. In breeding plumage it grows long plumes on the crown and nape.
The black heron occurs patchily through Sub-Saharan Africa, from Senegal and Sudan to South Africa, but is found mainly on the eastern half of the continent and in Madagascar. It has also been observed in Greece. and Italy.
It prefers shallow open waters, such as the edges of freshwater lakes and ponds. It may also be found in marshes, river edges, rice fields, and seasonally flooded grasslands. In coastal areas, it may be found feeding along tidal rivers and creeks, in alkaline lakes, and tidal flats.
The black heron has an interesting hunting method called canopy feeding—it uses its wings like an umbrella, and uses the shade it creates to attract fish. This technique was well documented on episode 5 of the BBC’s The Life of Birds. Some have been observed feeding in solitary, while others feed in groups of up to 50 individuals, 200 being the highest number reported. The black heron feeds by day but especially prefers the time around sunset. It roosts communally at night, and coastal flocks roost at high tide. The primary food of the black heron is small fish, but it will also eat aquatic insects, crustaceans and amphibians.