Pre-Construction Bird Monitoring Andrew Jenkins & Johan Du Plessis
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ADENHORST AM OLAR DEVELOPMENT AREA B D S PV Pre-construction bird monitoring Andrew Jenkins & Johan du Plessis. AVISENSE Consulting April 2014 CONTENTS Summary………………………………………………………………………………..…………….. 3 Introduction………………………………………………………………………………………..…... 5 Methods…………………………………………………………………………………………..…... 7 Development proposal……………………………………………………………………………… 7 Study area…………………………………………………………………………………………… 7 Data collection……………………………………………………………………………………… 8 Data analysis……………………………………………………………………………………….. 9 Results…………………………………………….………………………………………………… 10 Priority raptors and large terrestrial birds……………..………………………………..………… 10 Small passerines……………………..……………………………………………………..……… 10 Discussion………………………………………………………………………………………..….. 17 The affected avifauna………………………………………………………………………….…. 17 Impacts and mitigation……………………….…………………………………………………… 17 The need for post-construction surveys…………………………………………………………… 17 References……………………………………………………………………………………..……... 18 Appendix 1……………….………………………………………………………………………….. 21 Appendix 2…………………………………………………………………………………………. 38 2 Summary Solar photovoltaic (PV) energy installations have only recently begun in South Africa. While the development footprint of such facilities is often very large, little is known about the impacts of building and operating solar PV plants on the surrounding birdlife. This study presents the results of a series of surveys intended to characterize the avifauna of an area of ranchland which has been targeted by Mulilo Renewable Energy (Pty) Ltd for solar energy development (1 x 100 MW and 4 x 75 MW solar PV plants, covering a total of about 1000 ha), at a location just outside De Aar in the Northern Cape. These survey data are intended to establish a baseline against which to measure the impacts on birds of this proposed complex of solar PV arrays (the Badenhorst Dam Solar PV Development Area), as part of an extension of the avian impact assessment process, and in compliance with a condition stipulated in the Environmental Authorisation for the project/s. The anticipated impacts of the proposed solar PV development include habitat loss, displacement and disturbance of regionally endemic and/or red-listed species (imposed by construction and operation of the solar PV arrays spread across a considerable aggregate development footprint), possible mortality of large terrestrial species and raptors (resulting from collision with or electrocution on new power infrastructure), and possible changes in the avian species assemblage both within and around the development footprint (resulting from substantive changes in habitat quality that might benefit some species at the expense of others). The broader impact zone of the proposed PV energy developments is contained within an extensive tract of essentially flat, Nama Karoo shrubland, while the immediate vicinity features degraded natural veld with some anthropogenic influences. The area potentially supports over 200 bird species (including up to 13 red-listed species, 69 endemics, and five red-listed endemics), although this level of diversity is probably only approached after periods of exceptional rainfall. The birds of greatest potential relevance and importance in terms of the possible impacts of the planned solar energy development and its ancillary infrastructure are likely to be (i) local populations of endemic and red-listed passerines, (ii) any threatened raptors resident and breeding within or close to the development area, and (iii) seasonal influxes of large terrestrial species (especially bustards and cranes). The present study focuses on developing a quantitative understanding of the small passerine avifauna, generated in terms of a series of three site visits conducted over a 10-month period. While our surveys included a good range of the potential climatic variation available to us, there were no significant rainfall events in the area during the study, so we were not able to sample the avifauna at its most abundant and diverse. During each site visit we conducted 14 walked distance transects (415-1140 m in length), through a representative sample of the avian habitats present both directly within and adjacent to the proposed development footprint. On each transect, we identified and counted all the small terrestrial birds encountered, and recorded the approximate perpendicular distance from the transect line of all sightings. Transect data were processed using Distance 6.0 software, and density estimates were generated for all species combined, and for a sub-sample of the most frequently encountered species as well as those of particular conservation concern. 3 Over the entire study period, we recorded a total of 54 species in and around the Badenhorst Dam Solar PV Development Area (or about 25% of the maximum potential avian diversity), including 24 endemics or near-endemics, four red-listed species, and four red-listed endemics. Of the larger priority species, we encountered small numbers of Ludwig’s Bustard Neotis ludwigii on the site during all three iterations, and heard (but didn’t see) Blue Cranes Anthropoides paradiseus in the area in March 2014. Small passerine densities averaged 2.79 ± 0.45 birds.ha-1, with a statistically significant change in estimated densities over the three iterations of the study. The mean density of birds measured within the proposed development footprint was not significantly different to the density measured directly outside it (2.79 ± 0.62 birds.ha-1 vs 2.66 ± 0.61 birds.ha-1 respectively). Extrapolation from the within-footprint density estimate suggests that >2700 small passerines are likely to be directly and adversely affected by the construction of the full development proposal. Within-species variation was marked in some of the more frequently encountered and abundant species throughout the study (e.g. Eastern Clapper Lark Mirafa facsciolata, 0.02-4.20 birds.ha-1), and less so in others (e.g. Spike-heeled Lark Chersomanes albofasciata, 0.35-1.18 birds.ha-1). These density values for small birds found in and around the Badenhorst Dam Solar PV Development Area are estimates only, derived from a sampling and analysis approach that was no more than adequate for purpose, and did not encompass the full, potential variation in environmental conditions (and consequently bird numbers and diversity) that could prevail in the area. However, we consider the work sufficient to constitute a baseline profile of the avifauna most likely to affected be affected by the proposed development. This baseline profile is only of substantive value if followed up by a directly comparable study of the area conducted after the various solar facilities have been installed and built. Provided that the climatic conditions during such a post-construction survey are broadly similar, comparison of the two datasets should allow for a far improved understanding of the net effects of solar PV facilities on the local avifauna, and the implications of further such developments, spread over a much wider cumulative area, on the conservation status of endemic Karoo birds. 4 INTRODUCTION Commercial-scale renewable energy development is a recent phenomenon in South Africa, and has grown exponentially over the last five years. Solar photovoltaic (PV) plants have comprised a significant proportion of this burgeoning industry, making up about 38% of the country’s current and future renewable energy mix (http://www.sapvia.co.za/solar-pv/), with a long-term goal of up to 8000 MW of installed solar PV capacity by 2020. The environmental impacts of solar PV developments globally have not been well-researched (Tsoutsos et al. 2005, Gunerhan et al. 2009, Lovich & Ennen 2011, Tunney & Fthenakis 2011), and the impacts of these plants on birds are poorly understood (RSPB 2011, DeVault et al. 2014). While solar PV facilities are not obviously a source of anthropogenic avian mortality (unlike wind and concentrated solar energy facilities), they do cover large areas (about 2-5 ha per MW) and in many cases require the complete removal of vegetation from the inclusive footprint of the installed plant (Lovich & Ennen 2011, DeVault et al. 2014). It is this tendency to destroy, degrade, fragment or otherwise displace birds from large areas of natural habitat that stimulates most concern about the implications for avifauna of large-scale solar PV development (Lovich & Ennen 2011, RSPB 2011, Smit 2012). Other potential impacts include noise and disturbance generated by construction and maintenance activities, collision and electrocution mortality associated with newly installed power infrastructure (Bevanger 1994, 1998, Lehman et al. 2007, Jenkins et al. 2010, 2011, Dwyer et al. 2014), the attraction of novel species to an area by the artificial provision of otherwise scarce resources – for example perches, nest sites and shade (DeVault et al. 2014), the introduction of polarized light pollution and the possibility that this will confuse overflying birds with resulting collision mortalities (Horváth et al. 2009, Lovich & Ennen 2011), and the knock-on effects of water extraction, accidental pollution and the use of dust suppressants (Lovich & Ennen 2011). Mulilo Renewable Energy (Pty) Ltd is planning to construct five Solar PV facilities (1 x 100 MW and 4 x 75 MW, all collectively termed the ‘Badenhorst Dam Solar PV Development Area’) at a location just outside De Aar in the Northern Cape. The first of these PV arrays (PV1) has already been authorized and selected by the national renewable energy procurement process and will soon be under