Impacts of power infrastructure
Over the last few years the Fitz has been involved in projects to mitigate the impacts of power generation and transmission infrastructure. 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.
This programme, which is run in close collaboration with BirdLife South Africa’s Birds and Renewable Energy programme, received a considerable boost in 2016 with the awarding of a grant from the Hans Hoheisen Charitable Trust to fund a full-time research assistant for three years. Vonica Perold, a former field assistant on Marion Island, was appointed to this position from August 2016. A presentation to the ABAX Foundation in December 2016 also resulted in further funding to model the impacts of wind farms on Verreaux’s Eagles Aquila verreauxii.
Activities in 2016
- The large-scale experiment to test the efficacy of transmission line marking (using flappers or static flight diverters) to reduce collision mortality continued in the De Aar region of the eastern Nama Karoo thanks to ongoing monitoring by staff from the Endangered Wildlife Trust (EWT). Jess Shaw, now based in the UK, updated preliminary analyses showing a benefit to marking lines for Blue Cranes Anthropoides paradiseus, but not for Ludwig’s Bustards Neotis ludwigii.
- 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. A review of the first year of bird mortality monitoring at eight wind turbine facilities led by Samantha Ralston found that a wide variety of birds were killed; the 340 bird carcasses found represented 80 species from 38 families, including 16 families of passerines. Raptors are the species of greatest conservation concern, with significant numbers of both Accipitriformes (60 birds from 11 species) and Falconiformes (50 birds from 5 species) killed. However, flufftails were surprisingly frequent victims given their general rarity, with 5 individuals from 3 species killed.
- Building on the success of Tim Reid’s model to predict the impact of wind farm developments on Bearded Vultures Gypaetus barbatus (Reid et al. 2015, J. Appl. Ecol.), similar data are now being used to manage impacts of wind farms on Verreaux’s Eagles. Megan Murgatroyd was awarded her PhD in June 2016 for her study of these iconic eagles. She continues as a post-doc at the Fitz studying how this eagle’s movement patterns renders it susceptible to colliding with wind turbines. At least five Verreaux’s Eagles have already been killed by windfarms in South Africa, with three killed at a single facility. By understanding where and when eagles are vulnerable to collisions, we can advise developers on plant design, and potentially stop problematic turbines during periods of high risk to eagles.
- Accurate movement data also are being collected for Blue Cranes in the Overberg to better understand how cranes move in this region, which is home to the world’s largest population of this species. Cost-effective solar-powered GSM-linked GPS loggers have been deployed on the cranes using harnesses, so they should provide long-term data on their movements. The EWT’s Tanya Smith is leading this project, but the plan is to recruit a CB MSc student to analyse the data in 2017.
- Industrial-scale solar power generation also is growing rapidly in South Africa, with little information on the impacts on biodiversity. CB MSc student Elke Visser was awarded her degree in 2016 for her study of the impacts of the Jasper 96 MW photo-voltaic plant near Postmasburg in the Northern Cape. She found very few mortalities, and even accounting for a fairly high scavenger removal rate of small birds, it is unlikely that significant numbers of any bird species are being killed by the facility.
- CB MSc student Corey Jeal conducted a similar study of a concentrated solar power (CSP) ‘trough’ facility, Bokpoort, near Groblershoop. This plant uses parabolic mirrors to heat a synthetic oil to almost 400°C. Corey found few direct impacts on birds, and limited evidence of attraction of macro-invertebrates to the facility. The main concern surrounded animals drowning in the plant’s evaporation ponds. Like Elke, Corey found that the bird community in the plant area differed significantly from adjacent untransformed land mainly as a result of open-country species being favoured following the removal of bush cover. However, some species benefited from the installation, notably Barn Owls Tyto alba, which use the mirror support tubes as roost sites.
- Megan Murgatroyd was awarded her PhD in June 2016 for a comparison of the Verreaux's Eagles breeding in the natural area of the Cederberg and those breeding in the transformed Sandveld. Megan's first paper on the fine-scale movement patterns in these two areas was published in PLoS ONE.
- Julia van Velden had two papers from her CB MSc project on Blue Cranes published: one reported estimates of adult survival based on Kevin Shaw’s long-term ringing study (Ostrich) and the other examined the basis of potential conflicts with farmers in the Swartland and Overberg regions of the Western Cape (Environmental Management).
- Elke Visser obtained her MSc after studying the impacts of a large photovoltaic solar plant.
- GSM-GPS trackers were deployed on Blue Cranes in the Overberg region to track their long-term movements in collaboration with the EWT and CapeNature.
Endangered Wildlife Trust-Eskom Strategic Partnership; Hans Hoheisen Charitable Trust; Mazda Wildlife Fund.
Prof. Peter Ryan (FIAO, UCT)
Dr Arjun Amar (FIAO, UCT)
Samantha Ralston-Paton (BLSA)
Dr Andrew Jenkins (ADU, UCT)
Dr Megan Murgatroyd (FIAO, UCT)
Vonica Perold (FIAO, UCT)
Dr Jess Shaw (FIAO, UCT)
Dr Rob Simmons (FIAO, UCT)
Tanya Smith (EWT)
Students: Corey Jeal (CB MSc, UCT), Julia van Velden (CB MSc, UCT), Elke Visser (CB MSc, UCT)