They are small ibises with plumage that is strikingly different from that of any other ibis in Africa. I admire them for many reasons, but there was a time when some people, notably ancient Egyptians, considered them sacred. The god Thoth (Djehuty) had the head of an ibis. According to the old mythology, Thoth brought hieroglyphic writing to the people. He was a patron of literature, astronomy and other sciences, and the arts. Thoth’s siblings were Ptah and Osiris. The mummies of sacred ibises were placed in the tombs of pharaohs. Claudius Aelianus, writing circa 200 A.D. about his hunting expeditions in Egypt’s papyrus wetlands, stated that the people forbade the killing of these little white feathered birds with the naked black heads and legs, and preserved marshes to assure that there would be a never-ending supply. Ironically, the modern range of Threskiornis aethiopicus no longer includes Africa north of the Sahara, but does include nations south of the Sahara as well as a localized area in Iraq far to the north. The sacred ibis is invasive in France and has established populations in Spain and Italy. Their ancestors were captives that escaped. Zoos must keep them confined in aviaries to prevent escapes and naturalization into the wild where they compete with native ibises and herons for food and territory.
Sacred ibises are found south to South Africa east to Eritrea and Somalia, west to southwestern Mauritania, and north to Sudan. They adapt well to a wide variety of habitats where there is a reliable supply of water. They prefer riparian (riverine) habitats, and are also observed along lakes and on rocky marine islands. Towns throughout South Africa often attract these small ibises which many call “chimney sweeps” because they “sweep” away carrion. The favored food of the sacred ibis include crustaceans, insects, spiders, fish, frogs, small mammals, molluscs, and eggs. Carrion is consumed if other food is scarce.
Sacred ibises weigh approximately 1.5 kilograms at maturity and are approximately 65 to 75 centimeters in total body length with a wingspan of approximately 124 centimeters. Most of the body is covered in white feathers with black feathers on the tail. The flight feathers are white with dark blue-green tips. The skin over the breast is red. Males are somewhat larger than females; in all other aspects males and females look alike. At a distance the birds may be mistaken for the cobalt blue hadeda ibis which is the same length and height but upon closer inspection the completely feathered head of the hadeda serves to distinguish the two. The sacred ibis breeds once yearly. Breeding season in South Africa is from March to August. Adults are generally very quiet. Males will make small squealing sounds when fighting over females. Chicks are the noisiest. Mated pairs seek out a large nesting colony. Females lay an average of two white or bluish slightly round red spotted eggs. After 28 days the chicks hatch and 48 days later are fully fledged and ready to follow their parents as they seek food. These birds can be seen in their natural habitats at Modderfontein Nature Reserve in Gauteng, Glen Austin Bird Sanctuary in Johannesburg, False Bay Ecology Park in Cape Town, Rietfontein Nature Reserve near Matjiesfontein and Die Oog Bird Sanctuary in Cape Town.
The International Union for Conservation of Nature’s “Red List” of Threatened Species lists the sacred ibis as “Least Concern”, meaning that the world’s population is sufficiently large and well distributed and there is currently no cause for concern among ecologists and other biologists that the population is threatened. This status also means that the adult population has not been seen to decline more than ten per cent over the last three generations.