Abyssinian Ground-hornbill

*For the southern ground-hornbill, click here*

## About

A male Abyssinian ground-hornbill in long grass.

the Abyssinian ground-hornbill ***(Bucorvis abyssinicus)*** which inhabits the Sahel region of Africa. Abyssinian ground-hornbills are primarily black in plumage, with the exception of their pale grey or white flight feathers, which typically are only visible during flight. Ground-hornbills have characteristically bare patches of skin around their eyes and on the front of their throat. The skin is uniformly dark blue on the female but is primarily red on the male's throat and the same dark blue around the eyes. The Abyssinian ground-hornbill has long but thick legs with four toes, three facing forward and one facing backward, the structure of which allows the ground-hornbill to adopt a terrestrial grazing lifestyle. One way to distinguish the Abyssinian ground-hornbill from the very similar southern ground-hornbill ***(Bucorvis leadbeateri)***, is the very apparent casque on the top of its bill. Both sexes possess this feature and it is noticeably more pronounced than that of the southern ground-hornbill's. Another characteristic feature of the Abyssinian species is the small patch of dull red towards the base of the majority black bill. Abyssinian ground-hornbills grow to a length/height of 90-110cm (35-43in) and can weigh up to 4kg (8.8lbs). The wingspan of the ground-hornbill is only 49.5-59.5cm (19.4-23.4in), which makes it the second largest hornbill species behind the southern ground-hornbill.

## Diet

The Abyssinian ground-hornbill is a primarily carnivorous species, commonly being known to opportunistically follow migrating ungulates and forest fires in hopes that the large herbivores and the fires disturb smaller prey items and cause them to make themselves apparent. Ground-hornbills have been known to upturn soil and dig for arthropodal prey like insects and arachnids and even attack beehives to acquire honeycomb. They use their strong curbed beaks to attack and subdue various prey species such as; puff adder ***(Bitis arietans)***, cobras, lizards, tortoises, hares and mongooses. A ground-hornbill can travel up to 11km (6.8mi) in search of food. In times of scarce food availability, a ground-hornbill will not hesitate to eat carrion, but will rarely eat plant matter.

## Conservation Status

The Abyssinian ground-hornbill is classed as a vulnerable species by the IUCN and is threatened by a multitude of factors, namely deforestation and habitat destruction. This issue has been particularly stressing in west Africa, where the ground-hornbill has become close to extinct in a vast majority of faunal reserves and national parks in Togo, with the exception of the Fazao-Malfakassa National Park and even this site is being threatened by road development plans. In Benin, a similar situation has arose due to agricultural expansion and land development. Urban development has threatened the species as a whole across their population.

## Range and Population

The Abyssinian ground-hornbill occurs throughout the Sahel region of north Africa, a geographical area which serves as a transitional point between the tropical sub-Sahara of the south and the arid north. Ground-hornbills prefer areas of sparse vegetation, typically enjoying grassland, savanna and scrubland habitats. They usually avoid forested areas, -with the exception of arid woodlands, which have little foliage coverage- as to make foraging easier. Abyssinian ground-hornbills can be found in disturbed areas (typically pertaining to environmentally altered areas) however, they do require tall trees in order to nest. They also inhabit cliffsides and rockier mountainous habitats. Though the population of the Abyssinian ground-hornbill is unquantified, it is said that the species is common throughout its range however, it is suspected that it is declining.

## Behaviour

The Abyssinian ground-hornbill is a social species, travelling their territory of around 100km² (62mi²) in pairs or small groups that can reach up to 20 individuals (though this is rare). They rarely fly unless threatened, flying into a tree to roost, defending territory or attempting to capture prey. Groups are usually formed due to the insistence of the juvenile hornbills to remain in their parent's home range for several years, prompting multiple to congregate around adult hornbills. The adult breeding pair of the group often perform duets, emitting a low booming 'w*uh-wuh-wuh-wuh'* call in succession with one another. Juvenile Abyssinian ground-hornbills have been observed 'bill-wrestling' (a form of play fighting) and playing with vegetation. It is thought that these object manipulation behaviours assist in the creation of crucial motor skills, which assists adult Abyssinian ground-hornbills in practical application. Breeding season occurs in different increments depending on the region of habitation, with west African populations breeding in June-August, Nigerian and Ugandan populations breeding in January and Kenyan populations breeding as late as November. Nests are constructed in tree cavities, where baobabs ***(Malvaceae)*** and palm stumps ***(Arecaceae)*** are preferred however, they will tolerate rocky crevasses or even man-made shelters like beehive logs and baskets. Males initially create the nest by lining the chosen cavity with dry leaves and will partially seal the female within the cavity with the use of mud, dirt and vegetation. Unlike most hornbill species, the female Abyssinian ground-hornbill will not moult all her flight feathers during incubation. The female will then lay two or so eggs over a period of 5 days however, the first laid egg will be incubated first, resulting in the other chick typically starving to death within the first 4 days of hatching, while the first born has doubled its weight since birth. After 37-41 days of incubation, the nest's cleanliness is no longer maintained and the male provides food for the female. Proceeding the next 21-33 days, the female will emerge from the nest to assist the male in foraging and the chick will then fledge in the following 80-90 days. The juvenile will accompany their parents everywhere for up to 3 years however, sexual maturity is reached as early as their first year. As a product of a slow-reproductive cycle, only one chick is raised to adulthood every 9 years and so, parental endorsement is incredibly high.

### Relationship with Humans

Abyssinian ground-hornbills have been valued by local hunters, who kill the birds and hang their neck and heads from their neck. They do this as they believe it makes them seem innocuous to ungulate game and quarry. In the northern areas of Burkina Faso and Cameroon the birds are also hunted for food. The ground-hornbill is also sometimes killed in retaliation for breaking windows whilst fighting its own reflection. Quite adversely, in some areas the Abyssinian ground-hornbills duets are mimicked and even inspire culturally important songs.

## In Captivity

The Abyssinian ground-hornbill is a popular zoo species and can be found at over 30 zoos and institutes throughout Eurasia and the continental United States. Diseases have been found as a problem for the species in zoos, with the ground-hornbill already hosting parasites and viruses frequently in the wild. In north Africa, this issue has been apparent in that captive birds have died as a result of infection via West Nile virus.

## Sources

* IUCN Red List of Threatened Species - https://www.iucnredlist.org/species/22682632/132204438
* Abyssinian Ground Hornbill | Wikipedia - https://en.wikipedia.org/wiki/Abyssinian\_ground\_hornbill
* Abyssinian Ground Hornbill | Animal Diversity Web, University of Michigan Museum of Zoology - https://animaldiversity.org/accounts/Bucorvus\_abyssinicus/
* Abyssinian Ground-hornbill | eBird - https://ebird.org/species/noghor1?siteLanguage=en\_AU
* Abyssinian Ground Hornbill | ZOOINSTITUTES - https://zooinstitutes.com/animals/abyssinian-ground-hornbill-252/