Pied crow in South Africa: integrating ecological and social dimensions for effective management

Adelola, Temitope

Pied crow in South Africa: integrating ecological and social dimensions for effective management

Thesis / Dissertation

2024

Publisher

University of Cape Town

Department

Department of Biological Sciences

Faculty

Faculty of Science

Abstract

The Pied Crow (Corvus albus) has experienced a significant increase in abundance and distribution in recent decades in South Africa, mainly attributed to human-driven factors such as agriculture, climate change, and urbanization. This growth is particularly notable in the arid regions of the Succulent Karoo and the Fynbos biomes. Due to their opportunistic scavenging and potential predation on natural prey and livestock, concerns have been raised about the perceived negative ecological and economic impact. The impact of Pied Crows on wildlife and agriculture has become more evident, necessitating interventions from conservationists, farmers, scientists, and the public. A workshop conducted by BirdLife South Africa emphasized the urgency for research into diverse facets of Pied Crow behaviour and its impacts. Given the species' expansion and its socio-ecological impact, my dissertation aimed to explore both biological and social-ecological aspects through field surveys and an online survey. My dissertation comprised two data chapters (Chapter 2 & 3). Chapter 2 focused on the impact of roadkill on Pied Crow abundance and breeding success, while Chapter 3 explored the perception and knowledge of Pied Crows in South Africa, with a specific focus on farmers and non-farmers. Chapter 2 explored the impact of roadkill on Pied Crow breeding success and abundance through intensive and extensive studies conducted in Calvinia from 2018 to 2019 and the Karoo of South Africa in 2021, respectively. The hypothesis posited that Pied Crows would have higher abundance and higher breeding performance along roads with more roadkill. I also hypothesized that roadkill availability may differ between road types (paved and unpaved roads) because paved roads have more vehicles traveling faster, which would increase roadkill prevalence. If this was the case, and if roadkill is an important food resource for this species, the research expected differences in Pied Crow abundance and breeding performance along paved or unpaved roads. The question was explored both intensively for 2 years within a restricted study area, where Pied Crow breeding performance could be monitored, and extensively using a snapshot monitoring approach over a larger spatial area. Paved roads exhibited a higher incidence of roadkill, but no significant differences were found in Pied Crow abundance and breeding success between road types. However, farming activities and power lines were associated with a higher Pied Crow abundance, suggesting additional factors influencing their populations. In Chapter 3, I conducted a questionnaire to explore human perception and knowledge regarding Pied Crows and their potential impacts. Conducted online using Survey Monkey tool, I gained a total of 1193 responses from the public, of which 22.8% (n = 272) were farmers. My findings revealed a widespread perception of an increase in Pied Crow size, with farmers expressing a more positive outlook compared to non-farmers. However, negative perceptions arose due to their perceived impact on biodiversity and livestock, leading to a positive inclination towards management. My findings confirm a widely shared perception of the Pied Crows' role in the ecosystem, which remains consistent across different respondent types, signifying universally acknowledged ecological importance. However, diverse perceptions emerged regarding the impact of Pied Crows on biodiversity and livestock. Notably, the North West and Northern Cape provinces demonstrated the strongest agreement that Pied Crows negatively affect biodiversity. In my exploration into farmers' awareness of control methods employed against Pied Crows by their neighbours over the past decade, I uncovered significant regional differences. The Northern Cape, North West, Eastern Cape, and Free State provinces showed higher probabilities of farmers perceiving their neighbours to use control methods. Shooting and nest destruction were more commonly perceived to be employed by neighbours, while trapping and poison were reported less frequently. Interestingly, the type of farming practices did not influence farmers' perception of classifying Pied Crows as predators. However, economic values attached to sheep, goat, and cattle were linked to a higher likelihood of perceiving Pied Crows as predators.

Keywords

Biological Sciences

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