This project mitigates the impacts of power generation and transmission infrastructure on birds and other biota. Initial attention was focused on collision impacts associated with powerlines, which mainly affect large, open-country birds such as bustards and cranes that are unable to react rapidly when they encounter aerial obstructions. More recently the project has considered the impacts of renewable energy technologies, including wind and solar power generation.
Wind and solar power generation have much less broad-scale environmental impact than the coal-fired power stations on which South Africa relies for most of its power generation, but both technologies can have significant impacts at a local scale. The aim of this programme is to provide practical solutions to reduce the impacts of renewable energy projects, as well as energy transmission infrastructure, on birds in southern Africa. The programme is run in collaboration with BirdLife South Africa’s Birds and Renewable Energy programme, the Endangered Wildlife Trust (EWT) and HawkWatch International.
Activities in 2022
- PhD student Christie Craig, based at the Endangered Wildlife Trust, is studying the viability of Blue Crane Anthropoides paradisea populations in the Western Cape and Karoo. Powerline collisions are one of the main threats to Blue Cranes, and has been the major focus of her PhD. Christie completed her field work in January 2022, and spent the remainder of the year analysing and writing. Her key findings are as follows:
- From powerline surveys in the Swartland, Overberg and Karoo, Christie estimated Blue Crane collision rates for each region. Her model identified distance to seasonal water as the most important predictor of collision in all three regions. Specifically, the probability of collision is much higher on lines closer to seasonal water bodies. Blue Cranes roost in shallow dams and pans, and are at risk of collision when flying in and out at low light. In the Karoo, the model identified close proximity to irrigated pasture fields as a secondary risk factor. From aerial survey data, Christie demonstrated that Blue Cranes in the Karoo forage extensively in irrigated lucerne pastures during winter, and powerlines surrounding these fields are high risk to cranes.
- Christie analysed the Blue Crane Coordinated Avifaunal Roadcount and SABAP data, updating an analysis done by Sally Hofmeyr in 2010. Across all CAR precincts, Blue Crane counts increased by 24% (95% CI: 3.4%- 51%) between 2000 and 2019, but between 2011 and 2019 declined by -19% (95% CI: -31%, -5.2%). In this analysis, Christie accounted for survey effort, using an imputing technique developed by Sally Hofmeyr and Les Underhill, so this decline is not a factor of declining participation in the project. This trend is driven by declining Blue Crane numbers in the Overberg. The reasons for this are uncertain, but breeding monitoring data indicates that fledgling success is half that of previous Overberg estimates, from Elsabe Aucamp’s study in 1993
- Robin Colyn’s proposal to upgrade his MSc to a PhD was approved. His study infers the factors determining the distributions of range-restricted larks in the Karoo and montane grassland regions of southern Africa. The Red Lark Certhilauda burra is a species of particular concern, given the large number of wind energy projects planned in the range of this localised, vulnerable species, and the high mortality rate of larks that undertake aerial displays at windfarms. He has completed his fieldwork, but progress towards his thesis has been slow following his emigration to Canada.
- MSc student Sanjo Rose completed her field-work on Agulhas Long-billed Larks Certhilauda brevirostris, a little-known, range-restricted lark in January 2022. The funding for Sanjo’s study was obtained from a wind farm development. Understanding the habitat use, breeding requirements and threats to nesting can help understand the likely impact of the wind energy infrastructure on this and other ground-nesting lark species in the Overberg. Sanjo submitted her thesis in November 2022.
- Meg Murgatroyd (FIAO Research Affiliate and HawkWatch International) and Arjun Amar continued their work aiming to understand the cause of Black Harrier Circus maurus collisions with wind turbines to enable appropriate mitigation. This project has deployed 10 GPS tags on harriers to better understand their movement patterns.
- A predictive space use model for the entire population of Cape Vultures Gyps coprotheres was completed and submitted for publication. This model was developed by Francisco Cervantes under the guidance of Arjun and Meg and involved collaborators from multiple different organizations.
- Chris Vennum started at the Fitz, working as the ABAX Foundation’s post-doctoral fellow. Chris’s research will be focused on building a predictive space use model of Martial Eagles Polemaetus bellicosus to help with the planning of wind energy facilities.
- An experiment to assess the effect of blade painting on avoidance behaviour of Verreaux’s Eagles Aquila verreauxii was initiated at a wind farm in the Northern Cape. This project led by Meg and Arjun, with help from Chris, trapped three eagles that are breeding in the immediate vicinity of the turbines. These tracking data will act as the ‘before’ data, and will be compared with ‘after’ data once a section of the turbines have their blades painted in 2023.
- Merlyn Nkomo started her PhD on the interaction between Jackal Buzzards Buteo rufofuscus and wind farms. Merlyn is supervised by Arjun and Meg with help in the field from Chris. In 2022, Merlyn caught and tagged eight of the 15 Jackal Buzzards that she is aiming to track for her thesis. She also began conducting interviews with stakeholders within the wind energy sector to better understand their research priorities and needs.
- Sanjo Rose submitted her MSc for examination.
- A manuscript describing the predictive space use model for the Cape Vulture was accepted for publication in Ecological Applications. The model was incorporated into DFFE’s protocol for Environmental Impact Assessments for the Cape Vulture.
Endangered Wildlife Trust-Eskom Strategic Partnership; The Bateleurs; BirdLife South Africa; BTE Renewables; Hans Hoheisen Charitable Trust; Leiden Conservation Fund; Dave Myers.
Research team 2022
Prof. Peter Ryan (FIAO, UCT)
A/Prof. Arjun Amar (FIAO, UCT)
A/Prof. Robert Thomson (FIAO, UCT)
Dr Chris Vennum (FIAO, UCT)
Dr Alan Lee (BLSA)
Dr Andrew Jenkins (Avisense)
Dr Megan Murgatroyd (HawkWatch International, FIAO, UCT)
Dr Francisco Cervantes (FIAO / SEEC, UCT)
Samantha Ralston-Paton (BLSA)
Tanya Smith (EWT)
Students: Robin Colyn (PhD, UCT); Christie Craig (PhD, UCT); Merlyn Nkomo (PhD, UCT); Sanjo Rose (MSc, UCT).