Marabou Stork

The Marabou stork is a bird famous for its scavenging habits. It is deemed the ‘ugliest bird on Earth’ because of its unkempt and shabby appearance. The other name associated with it is the “undertaker bird,” as that is how it looks when observed from behind; cloak-like back, and wings, skinny legs, and tufts of white hair on the head.

These birds are a boon to the ecosystem since they play a significant role in keeping the environment disease-free by disposing of decayed animal flesh and other waste produced by them. They are capable of digesting manufactured waste as well.

Description

Size: Length: 60 in (152 cm) Weight: 20 lb (9 kg)

Wingspan: 12 ft (3.7 m)

Bill: They have huge bills, 10.4 to 13.8 in (26.4 to 35 cm) long.

Body and coloration: These storks have a bare head and neck, with feathers starting to appear from the neck down onwards. A pink gular sac or neck pouch hangs down its foreneck, along with a neck ruff. There is also a second pouch, pinkish or reddish in color, not as prominent as the first one, hidden at the hindneck’s base amidst the white feathers. Their beak is massive and tapered, grayish-ivory in color, while the eyes are dark brown.
Their legs are thin and skinny, appearing white because of their feces but are actually black. They have black feathers on the upper side and white on the undersides.

The juvenile birds differ in color from the adults, having a brownish body and a smaller bill.

Range and Distribution

Marabou storks are seen throughout Africa, with population density highest between the Sahara Desert and South Africa.

Habitat

These birds inhabit a wide variety of African habitats, primarily arid areas that have a source of water. Such regions include grasslands, open savannahs, riverbanks, swamplands, shores of lakes, and receding water pools.

In recent times, they can be found close to human society, in places like landfills and fishing villages.

Diet

Scavengers, by nature, their diet primarily consists of carrion and other waste. However, they sometimes target smaller or weaker animals like the chicks of certain birds such as doves, passerine birds, pigeons, pelicans, flamingos, and cormorants.

While rearing young, the diet of these storks changes, as extra nourishment is required then. Thus they feed on fish, reptiles, frogs, insects, eggs, and young mammals.

Of late, they have started venturing into human habitations in search of an easy meal, eating almost anything found in the garbage.

Lifespan

Marabou storks live up to 25 years in the wild, and as long as 41 years when raised in captivity.

Behavior

• These storks are either solitary or thrive in small groups. However, they become communal, dwelling in larger numbers during breeding or migration.
• They have a unique way of catching prey, especially during a grass fire in their habitat. These birds march in front of the fire fearlessly to get hold of the animals trying to escape.
• When not in flight, these birds are typically lazy, standing motionless for long periods or resting in a hunched posture.
• They pant to lower their body temperature while they feel hot.
• These birds will clean the soil off their food before eating it.
• Though not too vocal, like other storks, it uses its throat sac to make noises during courtship. They also clatter their bills if it feels threatened.
• The Marabou stork is very ill-tempered and should be approached with caution. Those used to getting handouts have been known to attack humans when they don’t get anything to eat.
• They can fly up to heights of 13,000 ft, especially while scavenging, though they do not soar that high. Infact they mostly prefer searching for food while remaining near the ground level.
• When flying, they tuck their necks into an “S” shape to balance the weight of their heavy beaks.

Predators

Not usually preyed upon, these birds have sometimes been attacked by big cats like leopards and lions. Their main threats come from parasites like nematodes, Cestoda, and Trematoda.

Adaptations

• They are bald, that helps their head remain clean. In fact, as they spend a lot of time digging around carcasses for food, any feathers present would get clotted with blood and other wastes. 
• Its long bill allows it to pull the flesh from the carrion easily.
• The Marabou stork has hollow bones and legs, helping them sustain in the air as they cannot fold their legs when airborne. 
• It excretes on the lower regions of its body, like its legs and feet, that help them remain cool. Moreover, their feces also have strong antiseptic properties protecting them against infection.

Mating and Reproduction

Interestingly, Marabou storks breed during the dry season when food is ordinarily scarce, but because water begins drying up in several areas, it becomes easier for them to hunt for fish. They form colonies during this time, ranging from 20 pairs to almost a thousand. Mates are chosen based on their neck folds, with those having larger ones being preferred over others. Pairs are monogamous and tend to mate for life. The large, flat nests are built in trees using sticks, and leaves, where 2-3 eggs are laid at a time.

Life Cycle

The eggs hatch after a month, incubated by both parents. They are helpless at birth and are taken care of by their parents. At around 3-4 months, they reach fledgling status and take as long as 4-5 years to reach sexual maturity.

Conservation Status

The IUCN lists the Marabou stork as “LC” or “Least Concern”, with about 200,000 – 500,000 existing globally as per the 2006 records. The birds have adapted to living close to humans, and their populations have increased over time. However, in South Africa, they are labeled as “Near Threatened” because of the lower numbers found there.

Interesting Facts

• The bee has a commensalism-based relationship with the Marabou Stork, i.e., the bee benefits from the stork’s activities. After the bird has finished eating from a carcass, bees will use the remains as a source of food and shelter.
• Marabou feathers have been used as fashion accessories and as fishing lures.