Goliath Heron (Ardea goliath), Bongani Mabaso EcoPark, Sasolburg, South Africa © Duncan Butchart, 2013.
I was photographing dragonflies beneath the large Cottonwoods (Populus deltoides) at the water’s edge, when a huge bird glanced over the tree tops, banked sharply to one side, then dropped suddenly to make an elegant landing on the far bank of the dam.
The Goliath Heron is the largest of the world’s 65 heron species, measuring about 1.5 metres (5 feet) from the tip of its dagger-shaped bill to the end of its spindly toes. The pale yellow eyes give this piscatorial predator a cold, reptilian look and – if you can get close enough – its not hard to imagine that you are being be stared down by a dinosaur. For the tilapia, catfish or carp that make up the bulk of its diet, it is a greatly feared killer. Like all herons, its favoured hunting technique is simply to stand stock still in the shallows, waiting for prey to come within striking distance. Then, with its posture frozen, it inches its recoiled neck closer and closer, before making a lightning-strike plunge. The bill is typically opened slightly at the last moment, to ensure that the skewered fish can be ‘handled’ more easily, but even so, many wriggle free before they can be swallowed. This patient process can take half and hour or more, so these herons spend a lot of their time standing still.
Bongani Mabaso EcoPark is a small grassland reserve on the outskirts of Sasolburg – a large town around the ‘Sasol 1’ site where South Africa’s first oil-from-coal refinery is situated. A small stream flows through the reserve and is dammed in two places to provide ideal hunting conditions for Goliath Heron as well as African Darter and Reed Cormorant. The open grasslands are home to a wide variety of highveld birds including Cape Longclaw, Rufous-naped Lark, Long-tailed Widow, Cloud Cisticola and Northern Black Korhaan so it makes a perfect day-trip for birders based in Johannesburg.
Bongani Mabaso EcoPark, Sasolburg, South Africa, March 2013
Note: Although fish make up the bulk of the Goliath Heron’s diet, I once saw one catch and swallow a very young Nile Crocodile about the length of the heron’s bill. This observation was at Ndumo in northern Zululand.