School of Life Sciences

Woolly-Necked Storks – To Feed or Not to Feed, That is the Question!

Woolly-Necked Storks – To Feed or Not to Feed, That is the Question!

Dr Vuyisile Thabethe graduated with a PhD from the School of Life Sciences following her research on a familiar urban species in South Africa: the African woolly-necked stork (Ciconia microscelis).

Thabethe investigated aspects of their ecology in an anthropogenic changing landscape in KwaZulu-Natal, ie a landscape caused by the influence of human beings on nature.

The large wading bird belongs to the Ciconia family, is indigenous to Africa, and is typically highly sensitive to human disturbance. In the 1980s, it was considered one of the rarest storks in South Africa and listed on the Red Data List for Endangered Species.

The stork however made a comeback after the animals began colonising urban environments, especially in KwaZulu-Natal, and their numbers grew and they moved off the endangered red list all the way down to being a species of least concern in 2004. Their range has expanded dramatically, indicating that they are successfully breeding in urban areas.

Despite this remarkable discovery and persistence in an urbanised environment, Thabethe indicated that no ecological research had been conducted on this species in South Africa.

‘Given the ongoing anthropogenic land-use change and the scarcity of data on urban birds in Africa, it is of high importance to understand how this species persists and uses resources in urbanised environments,’ she said.

Thabethe investigated the foraging opportunities that could have contributed to the storks’ successful urban colonisation, and discovered that a significant number of residents deliberately feed the birds daily throughout the year, with many providing inappropriate food such as meat and bread. She also found that the birds displayed relatively tame behaviour, with some feeding from hand and others going inside homes to find food. Their utilisation and exploitation of anthropogenic food is a novel behaviour.

The species is popular with feeders and non-feeders alike in KwaZulu-Natal, and an appreciation of their presence motivated many urban dwellers to feed the animals in order to enjoy close sightings.

‘This hints at the value of garden feeding of wild animals in providing an accessible experience of wildlife to a human population increasingly disconnected from nature,’ said Thabethe.

She was particularly interested in how they had adapted to human proximity during their nesting season, and discovered that they had successfully established breeding sites in suburban areas rather than simply sourcing food from humans and returning to nest in natural or rural habitats. The introduction of exotic tree species into gardens of private residences also played a role in the establishment of breeding sites in suburban areas that were previously unsuitable for breeding.

Thabethe investigated what type of food the birds provided to their nestlings, and found that they nourished them with both natural, foraged food and anthropogenic food.

Her work demonstrated that these storks have the behavioural flexibility to take advantage of anthropogenic resources in suburban landscapes through habitat selection and tolerance of human proximity.

‘The recovery of the African woolly-necked storks in South Africa is a truly successful conservation story,’ said Thabethe. ‘Their expansion into human-dominated landscapes offers us a remarkable opportunity for studying a species in a post-recovery state as well as its potential to actually become overabundant in some areas.’

Thabethe hopes that her work will contribute to closing the gaps in the quest to obtain a global perspective on urban ecology.

The passionate biologist, who is from Ladysmith in KwaZulu-Natal, is continuing with postdoctoral research at UKZN. During her studies at the University, she received a scholarship enabling her to participate in the 10-day Darwin Scholarship Programme in the United Kingdom, and also attended several local and international conferences.

Thabethe thanked her supervisor, Professor Colleen Downs, for providing the opportunity to take on this project and her encouragement and guidance; her family and friends for their support and prayers; as well as those who assisted with her fieldwork and the study. She paid tribute to her husband, Mbuso Khambule, for his unwavering support and encouragement.

Words: Christine Cuénod

Photograph: Gugu Mqadi