Hadada Ibis

About the hadada ibis

The hadada ibis is a medium-sized wading bird native to Sub-Saharan Africa, best known for the loud "haa-haa-haa-de-dah" call it gives in flight, especially at dawn and dusk as birds leave or return to their roost trees. The name is onomatopoeic, echoing the call itself, and it shows up in the bird's alternate spelling, hadeda, still used in some South African bird lists. It was first given a scientific name in 1790 by John Latham, based on a specimen collected north of Mossel Bay; naturalist Anders Sparrman recorded at the time that local colonists already called it hagedash or hadelde.

Adults measure roughly 76 cm (30 in) long and weigh an average of 1.2 kg (about 2.65 lbs), with males and females looking alike. The plumage is grey to partly brown, with a narrow white stripe across the cheek sometimes called a "moustache," though it doesn't reach the corners of the mouth. Across the wings, the feathers carry an iridescent purple sheen created by microscopic structures rather than pigment. The legs are blackish and the bill is a heavy, down-curved grey-to-black tool that develops a red patch on the upper half during the breeding season, when the tops of the toes also turn red. Broad, powerful wings let the bird take off quickly and maneuver through dense tree cover.

Three subspecies are recognized, distinguished mainly by bill length and coloration. The nominate form found south of the Zambezi River is paler and shorter-billed; birds to the north and east, in places like Uganda, Tanzania, Sudan, and Ethiopia, are larger and longer-billed; and populations from Senegal to Congo and Kenya are darker brown with a brighter gloss. Because plumages vary between these zones, other subspecies names have been proposed over the years but are not widely accepted.

Behavior and diet

Hadada ibises roost together in trees in groups, flying out with loud calls each morning and returning with the same regularity in the evening. Outside of roosting and flight calls, they use a range of vocalizations: a single loud "haaaa" while roosting, and a low growl similar to a puppy's while foraging in company.

The species forages by probing soft soil with its long, curved bill, feeding on insects, millipedes, and earthworms, along with larger prey such as spiders, small lizards, and larger insects including the Parktown prawn. It also readily eats snails, which makes it a familiar and often welcome visitor to garden beds, and it is valued on golf courses and bowling greens for digging out the larvae of moths and beetles that damage turf. Like other ibises and probing feeders such as sanderlings and kiwi, the hadada has sensory pits near the tip of its bill that help it detect hidden prey such as buried larvae and earthworms even when it can't see them.

Hadada ibises are monogamous, and their pair bonds appear to last year-round. Breeding begins after the rains; in South Africa's Cape province, that typically means October and November. Unlike most ibis species, hadadas do not nest in colonies despite their generally sociable nature. Each pair builds a stick platform in the fork of a large tree branch, and both parents share incubation of a clutch of three to four eggs, a job that takes about 26 days. Once hatched, chicks are fed by regurgitation from both parents; many young die by falling from the nest, but the ones that survive fledge at around 33 days old.

Range and habitat

The hadada ibis occurs throughout Sub-Saharan Africa, in open grasslands, savanna, and wetlands, as well as in urban parks, school fields, green corridors, and large gardens. Countries within its range include Sudan, Burundi, Ethiopia, Senegal, Uganda, Tanzania, Gabon, the Democratic Republic of Congo, Cameroon, the Canary Islands, Gambia, Kenya, Somalia, Lesotho, Eswatini, Botswana, Mozambique, Zimbabwe, Namibia, and South Africa. The bird is not especially tied to water compared with some other ibis species, but it does favor moist, soft ground where it can probe for food, and it tolerates close proximity to people.

Over the twentieth century, the hadada's range in southern Africa expanded by nearly two and a half times, largely because tree planting in formerly treeless areas gave it more roosting and nesting sites, while irrigation projects created the soft, damp soil the species needs for foraging. The birds are non-migratory but will move nomadically in response to rainfall, particularly during droughts, tracking the conditions that make probing for food possible.

Conservation status

The hadada ibis is listed as Least Concern on the IUCN Red List, in a 2016 assessment by BirdLife International. It is widespread and common across its large Sub-Saharan African range, and in southern Africa its range has expanded.

The bird has done well alongside people. Tree planting and irrigation in towns, parks and farmland have opened up new habitat, especially in South Africa. That comfort around people has a downside: hadada ibises have a history of bird strikes at airports in Kenya and South Africa.