Pied Crow Corvus albus numbers are increasing in many parts of South Africa. Recent work at the Fitz suggests that the increase in Pied Crow numbers is a result of global warming and other anthropogenic factors, including the availability of nest sites on electrical infrastructure and increased food availability in urban areas and from road kills. In combination, these factors have seen the Pied Crow increase its abundance in some regions and expand its range locally. Our project investigates the expansion of this species, sometimes termed a ‘native invader’, and aims to understand what impacts these changes might have for biodiversity. Previous Fitz research has focused on quantifying predation on tortoises and avian nest predation. Our current research builds on that research, which suggested that crows may benefit from scavenging on the carcasses of road kills. We also work to gain a broad understanding of public perceptions on Pied Crows and their potential management.

As a generalist predator, Pied Crows may impose heavy predation pressure on a variety of prey species. Anecdotal evidence suggests that Pied Crows present a risk to threatened species, such as endangered breeding waders and range-restricted tortoises. Because they may prey on species that are important for processes like seed dispersal, increases in crow numbers may influence ecosystems, generally. Researchers and conservation organisations have begun drawing attention to the knowledge gap with regards to the ecological impacts of Pied Crows, emphasising the need for more studies. Indeed, there is little information about the basic life history of Pied Crows, which is an essential component for understanding the potential impacts of a predator. We aim to contribute to filling these knowledge gaps. .

Activities in 2024

  • MSc student Yusra Samsodien, funded by the Joan Wrench Kirstenbosch Scholarship (SANBI), joined the project. She is investigating Pied Crow range expansion in South Africa using SABAP2 data, and exploring how anthropogenic factors influence the changes observed, with a special focus on the Western Cape fynbos. Yusra will also examine the biodiversity impacts associated with increasing Pied Crow abundance on tortoise populations.
  • Yusra began her field work along the Eskom powerline at Sere Windfarm near Lutzville in the Western Cape to investigate the impacts of linear infrastructure on pied crow and tortoise numbers. Yusra undertook four 10-day field trips to count tortoises and crows at different distances from the powerline.

Highlights

  • Temitope Adelola submitted her MSc thesis entitled “Pied Crow in South Africa: integrating ecological and social dimensions for effective management” and graduated in September. Her study gave key new perspectives on the effect of roadkill on Pied Crow abundance and breeding success, including understanding the public’s perceptions of Pied Crows.
  • Yusra attended the Arid Zone Ecology Forum conference held in Calvinia in October. She won the award for the best student presentation for her talk titled ‘Pied Crow population changes in South Africa’. .

Impact of the project

This research aims to improve our understanding of the drivers of increasing Pied Crow abundances in certain regions of South Africa and determine the associated implications for conservation, and if so, what management actions might be most effective to deal with these concerns. .

Key co-supporters
Joan Wrench Kirstenbosch Scholarship (SANBI), Mastercard Foundation, BirdLife South Africa

Research team 2024
Team leaders and collaborators:
A/Prof. Robert Thomson (FIAO, UCT)
A/Prof. Arjun Amar (FIAO, UCT)
Dr Colleen Seymour (SANBI /FIAO, UCT)
Lizel Tolken (EWT)

Students:
Temitope Abisoye (MSc, UCT), Yusra Samsodien (MSc, UCT)