Abstract
Since the 1997 Kyoto Protocol, many of the world’s nations have agreed to limit their greenhouse gas emissions because they are the root cause of global climate change. This necessitated a commitment to move away from carbon-polluting energy sources such as coal and oil to renewable energy sources such as wind and solar power. South Africa signed the Kyoto Protocol and the Paris Agreements and is thus committed to reducing carbon emissions. This is a real issue in South Africa, because 86% of our electricity was generated by coal-fired power stations in 2016 and renewables accounted for less than 2% of electricity production (Statistics South Africa 2018). Renewable energy can play a role in conserving the world’s biodiversity which is otherwise required to adapt or perish in the wake of rapid climate change (Thomas et al. 2004, Simmons et al. 2004). Unfortunately, renewable energy comes with some negative impacts, namely disturbance, displacement, habitat destruction or direct mortality of birds through impacts with turbines, towers, mirrors or power lines (Drewitt and Langston 2006, Gove et al. 2013, Loss et al. 2013). With few exceptions (e.g. Altamont, USA and Tarifa, Spain) most studies suggest that the number of mortalities caused by collisions with wind turbines is currently relatively low compared to other sources of anthropogenic avian mortality (Erickson et al. 2001, Sovacool 2013). For example, losses due to non-renewable fossil fuel energy sources are estimated at 14.5 million birds annually in the USA, whereas wind energy there kills about 234 000 birds per year (Loss et al. 2013, Sovacool 2013). Despite the relatively low fatality rates at wind energy facilities (WEFs) the main issue that remains is that threatened species are often victims of turbine collisions. For example, in South Africa, Ralston-Paton et al. (2017) found that 36% of all carcasses found beneath wind turbines were large or small raptors, and 8% were threatened red data species. To avoid adding further pressure to threatened species, guidelines are needed to help wind energy expand with the least negative effects on populations. Bird species at risk from wind energy in South Africa have been prioritised (Retief et al. 2013, updated in Ralston-Paton et al. 2017) taking flight behaviour, wing loading, aerial display activity and other factors into consideration. Black Harrier Circus maurus, the scarcest endemic raptor in southern Africa (Taylor et al. 2015), was ranked sixth in this list of priority species (Cape Vulture Gyps coprotheres, Verreaux’s Eagle Aquila verreauxii, Bearded Vulture Gypaetus barbatus, Taita Falcon Falco fasciinucha and Martial Eagle Polemaetus bellicosus). Fatalities of Black Harriers have been reported from three WEFs in South Africa, confirming predictions that this species may be at risk. T his document provides an overview of the current understanding of the likely impact of wind turbines on Black Harriers and offers guidance on how the impacts should be assessed, avoided, mitigated and monitored (summarised in Figure 1). We also provide a brief introduction to Black Harrier ecology and pinpoint areas where Black Harriers are most likely to occur. Where data are limited, our recommendations have been supplemented with expert opinion. As our knowledge grows, the recommendations contained in these guidelines may be amended to reflect our improved understanding of how Black Harriers can survive alongside an increasing amount of power generated from wind. T hese guidelines expand on the recommendations in the BirdLife South Africa / Endangered Wildlife Trust Best Practice Guidelines for Birds and Wind Energy (Best Practice Guidelines) (Jenkins et al. 2015). These documents should, therefore, be read together.