There has to be total trust between breeding pairs of West African black casqued wattle hornbills (Ceratogymna atrata) because when the female goes to nest, the entrance is sealed up inside by the mother while the father seals it from outside.
For up to four months she is sealed inside the nest for protection as she warms her eggs and hatches the babies. A small slit is left open on one side of the nest, through which the father brings food to mom and babies. While she is encased inside, she also moults her feathers.
If something happens to the father while she’s sealed inside, both she and any babies would die.
This extraordinary tryst has been playing out at the Amazona Endangered Bird Breeding Facility in Assagay, just outside Durban, where owner William Horsfield confirmed the first breeding of the facility’s pair of West African black casqued wattle hornbills.
While this species of hornbill is not classified as endangered in its natural range, it is extremely rare in captivity around the world, according to Horsfield.
The Independent on Saturday visited the facility this week.
A misty fog enveloped the nest where only the beak of the female and her copper brown head were visible as she called out for food. (The breeding facility is not open to the public).
The baby hornbill was well hidden in the sealed nest, but the sleek black male with his unusual helmet and bright turquoise eyes was hugely protective, eyeing IOS photographer Shelley Kjonstad with a fair amount of suspicion.
Horsfield said that earlier this year, the female had been encased into the nest for more than three months. The staff hoped that breeding was successful, so they were hugely disappointed when she left the nest and it was empty.
“This time, she was in the nest for about 45 days when we heard a little voice. Then it went silent for about two weeks and we decided to do a nest inspection.
“With curiosity getting the better of me, I went to have a look but had to use a stainless mesh shield as both the male and female became extremely defensive of the nest log,” said Horsfield. He took a quick sneak peek and spotted the baby hornbill.
“There isn’t much literature on how long the female is likely to stay in the nest; she’s been there for three-and-a-half months now, so perhaps at around four months, she’ll break out.
“That’s when we expect the baby to also fledge and venture out into the world,” he said.
He said that with other hornbill species which had more than one chick, the mother would often break out and then seal the nest again for a short while to protect the chicks, while helping her mate feed the hungry brood.
When the nest is being sealed, both birds use their own faeces, food items and mud to make the walls, leaving the small slit for feeding.
As the IOS team watched, the male collected superworms which he swallowed, regurgitated and fed them one by one to his partner, who was ready for breakfast.
“Hornbills have a fascinating and complex reproductive biology. Anatomically, they have unique kidneys which allow the female to go without water for a sustained period of time while she is in the nest. The male will also take her moisture-rich foods such as fruit and berries,” said Horsfield.
The only hornbill species which does not seal the nest is the southern ground hornbill (Bucorvus leadbeateri) which is the largest hornbill found in the world and is typically found in KwaZulu-Natal and neighbouring southern Africa. It was nominated as Bird of the Year for 2020.
There are two pairs of southern ground hornbills at Amazona and a 7-day-old chick which is being cared for in an incubator in the rearing facility. Eggs may be moved to incubators if the parents are not doing well with an egg. While the chick’s eyes were still closed, Horsfield pointed out the tiny ears which were working well. To reassure the tiny chick, Horsfield and his assistant, Don Soko, vocalise by mimicking an adult hornbill.
“The chick goes into the sun every day for about two minutes which helps the skin to darken,” said Horsfield, adding that juvenile males are definitely ‘’mama’s boys’ when it comes to female southern ground hornbills.
“In the wild, the mother will kick daughters out of the family group once they are independent but keep their sons. The family group is made up of a breeding female, the mate and male chicks. The pair may also reject a son they don’t like,” he said.
In the next incubator, an egg was in the process of hatching another southern ground hornbill baby. Tiny scratching noises could be heard. Horsfield confirmed the new chick hatched later that day.
According to the SA National Biodiversity Institute (SANBI), the southern ground hornbill is classified as “vulnerable” globally by the IUCN ( International Union for the Conservation of Nature), but is classified as “endangered" in South Africa, Lesotho, Namibia and Swaziland. This is because of a severe decline in the species’ range by 50% over recent years, with a 10% decline in species over 30 years, according to the SANBI website. Habitat loss, secondary poisoning (such as lead bullets which hornbills may eat from hunted game such as guinea fowl) and direct persecution are among the threats, while it is also a slow-growing species with a low reproduction rate.
It is endemic to Africa and recognised by its striking black and red colours, with the white wings seen when they fly.
During the mating season, the red pouch on the neck of males and females can be inflated for courtship and communication. This pouch is used to make booming calls which are heard over long distances to attract females for mating, with the booming sound sometimes being mistaken for a lion’s roar. Adult females have a dark blue patch in the throat area, while juveniles have a pale cream pouch which gradually changes to red as the bird matures.
Also currently under way is the APNR Southern Ground Hornbill Project based in the Greater Kruger National Park which is working towards slowing the decline of the species. The project has called on citizen scientists to send photos and/or videos of the birds with date, time and location of sightings to [email protected] or for more information contact 072 345 6584.
The Independent on Saturday