Vultures and Wind Turbines

Wind turbines and power lines constitute another important problem for urban vultures, as these constructions are rapidly increasing in North America, Europe, Asia and Africa (Moccia and Arapogianni 2011; Martin et al. 2012). Large raptors, especially vultures and eagles are very vulnerable to collisions with wind turbines and power lines, despite their sharp vision (much sharper vision than human vision) (Land and Nilsson 2002). The vulnerability of these birds to collisions has become a factor for the decline of several species, an important international conservation issue and a topic at international conferences (Drewitt and Langston 2008; De Lucas et al. 2008; Carette et al. 2009; Jenkins et al. 2010; Martin et al. 2012).

The development of wind turbines was an important aspect of the policy to reduce greenhouse gas emissions by using renewable sources. The target of the European Commission was that 20% of the energy generated by European Union (EU) should have renewable sources by 2020. The Spanish government was committed to this by 2010 (AEE (Asociacion Eolica Espanola), 2009; Telleria 2009a; IDAE (Instituto para la Diversificacion y el Ahorro de la Energia) 2010). In Spain, renewable sources generated 14% of energy production (IDAE 2010). As wind was used as an energy source, the number of wind farms increased across Spain. About 16,842 turbines in 737 wind farms were operational, generating more than 16 GW (gigawatts) of electricity in 2009 (AEE 2009).

Wind turbines are an important factor for vulture mortality in modified landscapes (Telleria 2009a). De Lucas et al. (2012a). note that the wind turbine has developed into an important factor for avian mortality. In some cases, they kill more birds than power lines (Barrios and Rodriguez 2004). Examples occur in the Netherlands (Winkelman, 1990, 1992, 1995; Musters et al. 1996; Dirksen et al. 1998), USA (Orloff and Flannery 1993; Howell 1997; Morrison et al. 1998; Osborn et al. 2000; Erickson et al. 2002; Johnson et al. 2002; Thelander et al. 2003; Arnett 2005); Sweden (Peterson and Stalin 2003) and Spain (Barrios and Rodriguez 2004; Dorin et al. 2005).

Wind power plants are frequently sited near the breeding sites of vultures. Telleria (2009b) notes that there are no evaluations of the potential impact of the expanding wind power industry on the Spanish Griffon vultures which are described as more than 20,000 breeding pairs by Marti and Del Moral (2003). This is despite the documented incidents on wind turbines in Spain (Barrios and Rodriguez 2004). Spanish griffon vultures breed mainly in the northern half of the country, where there are thousands of turbines. Telleria (2009b) hypothesizes that the number of deaths may be high, as the wind power industry selects highlands and mountain rides or turbine location, precisely the places frequented by foraging vultures. Lekuona (2001) estimated a turbine generated death rate of eight griffons per year in one area near the Salajones wind plant, in Navarre, Southern Spain. Lekuona and Ursua (2007) also found the griffons represented 63.1 percent of bird fatalities near the wind plants of Navarre.

Another study by De Lucas et al. (2012b) studied Griffon vulture mortality at 13 wind farms in Tarifa, Cadiz, Spain, before (2006-2007) and after (2008-2009), when selective turbine stopping programs were implemented as a mitigation measure. The study found 221 dead Griffon vultures during the entire study. When turbines were stopped when vultures approached, the Griffon vulture mortality rate was reduced by 50% with a consequent reduction in total energy production of the wind farms by only 0.07% per year.