Sacred ibises are generally quiet birds. During the breeding season they produce a variety of vocalizations. In antagonistic situations, both sexes utter a variety of squeals, moans, and wheezes, sometimes described as: “whoot-whoot-whoot-whooeeoh” or “pyuk-pyuk-pek-pek-peuk”. Females make a series of “whaank” noises after the nest is built to attract the male, this is usually followed by copulation. Adults make a “turrooh” or “keerrooh” to call their offspring back to the nest. Adults make a high pitched “chrreeee-chree-ah-chreeee” to call offspring for feeding. They have also been observed making a loud croak during flight.
Communication Channels: visual ; tactile ; acoustic
Perception Channels: visual ; tactile ; acoustic ; chemical
Sacred ibises are not considered threatened in their native range. They have become a conservation problem in Europe, where they have been reported feeding on threatened native species as well as encroaching on the habitats of native species. This has become a concern for European conservationists trying to protect native threatened species.
US Migratory Bird Act: no special status
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
IUCN Red List of Threatened Species: least concern
Sacred ibises do not impact humans directly, but where they are introduced they may become a nuisance or may prey on bird species that are threatened or protected.
Ancient Egyptians revered sacred ibises. They mummified many of these birds and buried them in the tombs of deceased pharaohs, though they are now rare in Egypt. Sacred ibises are also important members of native ecosystems.
Sacred ibises are important wading birds throughout their range in Africa, consuming a wide variety of smaller animals, keeping their populations in check. In Europe, their adaptable nature has made sacred ibises an invasive species, sometimes feeding on rare birds.
Sacred ibises feed during the day primarily in flocks by wading in shallow wetlands. Occasionally they will feed on dry land close to water. They may fly a distance of 10 km to foraging grounds. They feed primarily on insects, arachnids, annelids, crustaceans, and mollusks. They have been observed eating frogs, reptiles, fish, young birds, eggs, and carrion as well. In more cultivated areas, they have been known to eat human refuse. This has been observed in France where they are becoming an invasive pest species.
Animal Foods: birds; mammals; amphibians; reptiles; fish; eggs; carrion ; insects; terrestrial non-insect arthropods; mollusks; terrestrial worms; aquatic or marine worms; aquatic crustaceans
Primary Diet: carnivore (Insectivore , Eats non-insect arthropods)
Sacred ibises are native and abundant in sub-Saharan Africa and southeast Iraq. There are introduced populations in Spain, Italy, France, and the Canary Islands from individuals that escaped from captivity and began breeding successfully.
Biogeographic Regions: palearctic (Introduced , Native ); ethiopian (Native )
Sacred ibises inhabit a wide range of habitats, although generally they are found in close proximity to rivers, streams, and coastlines. Their native range is sub-tropical to tropical, but they are found in more temperate areas where introduced. They often nest on rocky marine islands and have adapted to living in towns and villages.
Habitat Regions: temperate ; tropical ; terrestrial ; saltwater or marine ; freshwater
Aquatic Biomes: lakes and ponds; rivers and streams; temporary pools; coastal
Wetlands: marsh
Other Habitat Features: suburban ; agricultural ; riparian ; estuarine
Sacred ibises may live up to 20 years.
Typical lifespan
Status: wild: 20 (high) years.
Pure to dirty white feathers cover most of the body. Blue-black scapular plumes form a tuft that falls over the short, square-shaped tail and closed wings. The flight feathers are white with dark blue-green tips. Sacred ibises have long necks and bald, dull grey-black heads. The eyes are brown with a dark red orbital ring and the bill is long, downwardly curving, and with slit-like nostrils. Red bare skin is visible on the side of the breast and on the underwings. The legs are black with a red tinge. There is no seasonal variation or sexual dimorphism other than that males are slightly larger than females.
Juveniles have feathered heads and necks that are mottled white with black streaks. Their scapular feathers are greenish-brown and there is more black on their outer primaries and primary coverts. The underwing coverts have dark streaks. The tail is white with brown corners.
Average mass: 1.5 kg.
Range length: 65 to 75 cm.
Range wingspan: 112 to 124 cm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: sexes alike; male larger
There are few reports of predation on sacred ibises. As adults these birds are very large, discouraging most predation. Young sacred ibises are guarded carefully by their parents, but may be subject to predation by large raptors.
Sacred ibises form seasonally monogamous breeding pairs that nest in large nesting colonies.
During the breeding season large groups of males select a spot to settle and form pairing territories. In these territories males stand with wings held downwards and rectrices spread. In the following several days females arrive in the nesting colony, along with more males. Newly arriving males go to the established territories of settler males and compete for the territory. Fighting males may strike at each other with their bills and make squealing noises. Females choose among males and their pairing territories and pairs are formed. Once the pair is formed, the couple moves to a nearby nesting area selected by the female. Fighting behavior may continue in the nesting area between neighboring individuals of either sex. Individuals will stand with wings outstretched and head lowered with bill open towards other individuals. Individuals that are very close to each other may adopt a similar stance, but with bill pointed upwards, nearly touching, while making calls.
During pair formation the female approaches the male and, if she is not chased away, they face one another and bow with necks outstretched forward and towards the ground. After this they assume a standing posture and intertwine their necks and bills. This may be followed by more bowing or extensive self-preening. The pair then establishes a nest territory where copulation occurs. During copulation, females crouch so males may straddle them, the male may grab the females bill and shake it side to side. After copulation the pair again assumes a standing position and extensively preen themselves at the nest site.
Mating System: monogamous
Sacred ibises breed yearly in large nesting colonies. In Africa breeding occurs from March to August, in Iraq breeding is reported from April to May. Females lay from 1 to 5 (average 2) eggs, which are incubated for about 28 days. The eggs are oval shaped or slightly round, with a rough texture. The eggs are dull white with a blue tinge and sometimes dark red spots. Eggs are from 43 to 63 mm. Fledging occurs 35 to 40 days after hatching and the young become independent soon after fledging.
Breeding interval: Sacred ibises breed once yearly.
Breeding season: In Africa breeding occurs from March to August, in Iraq breeding is reported from April to May.
Range eggs per season: 1 to 5.
Average eggs per season: 2.
Range time to hatching: 21 to 29 days.
Average time to hatching: 28 days.
Range fledging age: 35 to 40 days.
Range time to independence: 44 to 48 days.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous
Incubation lasts for around 21 to 29 days, with most incubated around 28 days by both male and female, alternating at least once every 24 hours. After hatching one parent is present at the nest at all times for the first 7 to 10 days. The young are fed many times a day by partial regurgitation from parents. Young leave the nests after 2 to 3 weeks and form groups close to the colony. They are fed by parents once a day after leaving the nest. The fledgling period lasts from 35 to 40 days and individuals leave the colony at 44 to 48 days after hatching.
After eggs hatch, the parents identify and feed only their own offspring. When parents return to feed offspring, they give a short “keerooh” call. The offspring recognizes the parental call and may run, jump, or fly to the parent for food. If other young approach the parent, they will be chased away. When the offspring learns to fly, it may circle the colony until the parent returns to feed it, or even chase the parent around before feeding.
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Male, Female); pre-weaning/fledging (Provisioning: Male, Female, Protecting: Male, Female); pre-independence (Provisioning: Male, Female)
