What Do Shoebills Eat? Lungfish, Catfish and More

The shoebill’s main foods

The shoebill is a carnivore and a specialist fish-eater. Studies across its range in South Sudan, Uganda, Tanzania and Zambia point to a handful of key prey:

• Lungfish. The marbled lungfish (Protopterus aethiopicus) is the shoebill’s signature prey, and the West African lungfish is also taken. Lungfish are eel-like fish that breathe air with lungs as well as gills.
• Catfish. Air-breathing catfish of the genus Clarias, such as the sharptooth catfish, are a staple in many swamps, and in Zambia’s Bangweulu Swamps they are one of the main foods brought to chicks.
• Bichirs. The Senegal bichir, a long, armored, air-breathing fish, is another favorite.
• Tilapia and other cichlids where they are common.

The list has one thing in common: many of these fish breathe air and must rise to the surface regularly, especially in shallow, oxygen-poor water. That is exactly where a shoebill waits. The bird’s range closely matches the distribution of papyrus swamps and lungfish.

Other prey: frogs, snakes and young crocodiles

Shoebills are opportunists that will take almost any animal of the right size that comes within reach. Recorded prey includes:

• frogs
• water snakes, often 50–60 cm (20–24 in) long, which parents in Zambia also feed to chicks
• Nile monitor lizards
• baby crocodiles, presumably young of the Nile crocodile
• more rarely, small turtles, snails, rodents and small waterbirds
• occasionally carrion

These extra foods are a minor part of the diet, but they show that a shoebill’s huge, sharp-edged bill can tackle prey that other wading birds would never attempt.

How big are shoebill prey?

Shoebills take much bigger prey than herons and storks. In the Bangweulu Swamps, the fish they catch are mostly 15–50 cm (6–20 in) long. In the Malagarasi wetlands of western Tanzania, they often catch lungfish and catfish 60–80 cm (24–31 in) long, and the largest fish recorded was about 99 cm (39 in).

Swallowing a fish that long is not easy. Very large fish are usually cut into sections with the sharp edges of the bill and swallowed in stages. From strike to swallow, the whole process can take anywhere from 2 to 30 minutes depending on the size of the prey. While a shoebill struggles with a big fish, an African fish eagle sometimes swoops in to steal it.

How do shoebills hunt?

Shoebills hunt by sight alone, unlike some wading birds that feel for prey in murky water. A bird stands motionless at the edge of open water or on a mat of floating plants, or wades very slowly forward. It may hold still for many minutes at a time, watching the surface.

When a fish comes up to breathe, the shoebill strikes in a movement often called collapsing. It lunges or falls forward, wings often spread for balance, and drives its open bill down onto the prey. The bill closes on the fish together with mud, water and plants. The bird then lifts its head, shakes off the vegetation and water from the sides of the bill and repositions the fish before swallowing it whole.

Studies suggest that around 60% of strikes are successful. Shoebills hunt alone, usually keeping at least 20 m (66 ft) from other shoebills even where they are fairly common.

Why the bill is the perfect tool

Every part of the shoebill’s bill is suited to its diet:

• Size. The bill is about 19–24 cm (7.5–9.5 in) long along the top and very wide, so it can engulf a big fish along with the water around it.
• Sharp edges. The cutting edges of the upper and lower bill help it grip slippery prey and slice large fish.
• Hooked tip. A sharp nail at the tip of the upper bill helps pin and control struggling prey.
• Forward-facing eyes. Large eyes looking down along the bill give the shoebill good depth perception for an accurate strike.

The long toes also matter: they let the bird stand on floating vegetation over deeper water, giving it access to fish that other waders cannot reach.

Do shoebills compete with other animals for food?

In much of their range, shoebills share the swamps with herons, storks, pelicans and people who fish. The large Goliath heron sometimes hunts in the same places, and both birds can stand on floating vegetation. Herons usually catch smaller fish, though; see What do herons eat? for a comparison.

Some animals help shoebills by accident. Hippos moving through the swamp push fish toward the surface and open new channels, creating good hunting spots. Fishing by people is a different story: heavy fishing and disturbance in some wetlands reduce the prey available and can drive shoebills away from their nests.

What do shoebill chicks eat?

Both parents feed their chicks by regurgitating, or bringing back up, partly digested food, at first into the nest and later directly into the chick’s bill. In Zambia, the main foods brought to young were Clarias catfish and water snakes, while in Uganda parents fed their chicks mostly lungfish and catfish. Parents also bring water in their bills to cool the eggs and chicks on hot days. Young shoebills fly at about 3.5 months but depend on their parents for food for a month or more afterward while they learn to hunt.