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j RaptorRes. 33 (1) :43-48 ¸ 1999 The Raptor ResearchFoundation, Inc.

PREVENTING OF PREY PROBLEMS AT TRANSMISSION LINES IN WESTERN

PATRICK BAYLE 15 rue Bravet, 13005 Marseille,

Among the 37 speciesof birds of prey (28 fal- (Real et al. 1996) and Spanish Imperial coniforms and 9 strigiforms) that breed or winter (Ferrer and Hiraldo 1990). regularlyin westernEurope, at least30 (24 - Investigations in , France and iforms and 6 strigiforms) have been killed on pow- show that, among the 37 speciesof raptors that erlines,either through electrocutionsor, to a lesser breed or winter regularly in western Europe, at extent, through collisionswith electric wires. Mor- least 30 specieshave been victims of powerlines tality on medium voltagedistribution lines plays an (Table 1). Raptors most often found dead under important role in the global mortality of certain powerlines are common speciessuch as Common eagles, especiallyamong juveniles (e.g., Spanish ( Buteobuteo), Black Kites ( migrans) Imperial [Aquila (heliaca)adalbertz] in Spain and Eurasian . and Bonelli's Eagle [Hieraaetusfasciatus] in Spain Medium voltage powerlines (1-60 kV) are re- and southern France) and is responsiblefor the sponsible for most of the raptor mortalities on general decline of these .Powerlines also electriclines. In France,96.5% of 649 birdsof prey have an important impact on some common birds found dead under transmission lines were under of prey, both regionally (e.g., EurasianEagle medium voltage powerlines (Striot and Rocamora [Bubobubo in the southern French ) and lo- 1992). The low impact of high or very high voltage cally (e.g., Eurasian [Falcotinnunculus] in powerlines (60->150 kV) on raptors is illustrated different areas in France). Different devices have by studies of the avian mortality on portions of been developed to assure a better isolation be- such lines in the (Heijnis 1980), Ger- tween electric wires and pylons and to prevent many (Hoerschelmann et al. 1988), France (Bayle birdsfrom perching on electricpoles, but the most and Iborra unpubl. data) and which showthat efficient protectionis to bury the lines. Countries birds of prey representbetween only 0.1-0.4% of such the Netherlands (which have already all birds killed on theselines. In the French study achieved this aim), , Germany and the (Striot and Rocamora 1992), all birds of prey U.K. now intend to bury all their medium voltage found under high or very high voltagepowerlines lines. were killed by collision with transmissionlines. Since then an immature Bonelli's Eagle is known BIRDS OF PREY VS. POWERLINES IN WESTERN EUROPE to have died from electrocutionon a 63-kV power One of the major factorscausing declines in rap- structure near Marseillesin August 1992 (Cheylan tor populations is pollution, but forms of distur- and Bayle unpubl. data). Of the raptors killed on bance such as loss and persecution have medium voltage powerlines,93.5% were electro- adverseeffects on raptors(Newton 1979, Gensboel cuted and 6.5% collided againstelectric wires. 1984). Accidental deaths that come to notice usu- In France and Spain, the role of powerlines in ally involve collisions of raptors with vehicles, the general mortality of raptors has been studied buildings and other structures (Newton 1979). recently in specieswith small populationssuch as One of the human causesof mortality,which has the Spanish Imperial Eagle (Ferrer and Hiraldo been overlooked in Europe, is the powerline web 1990), (Aquila chrysaetos,Couloumy with which raptors collide or electrocute them- 1993), Bonelli's Eagle (Real et al. 1996) and Grif- selves.For certain species,collisions and electro- fon Vulture (Gypsfulvus, Terrasse et al. 1994). cutionson overheadwires form a major part of the Since this form of mortality affectsmainly juvenile total mortality and in extreme casesthey may have birds, it can have an important impact on the pop- contributed to raptor declines.This of mor- ulation dynamicsof these speciesand be critical tality is a major threat for speciessuch as Bonelli's for their survival. Between 1974-88, 51.5% of 68

43 44 EXPANDEDABSTRACTS VOL. 33, NO. 1

Table 1. Raptor speciesaffected by mortality on electricpowerlines in three European countries(Germany, France and Spain).

SPECIES D a F E

Osprey ( Pandionhaliaetus) ..{-b Common ( buteo) +++ Rough-leggedBuzzard ( Buteolagopus) + Honey Buzzard (Pernisapivorus) + + Black ( Milvus migrans) + + ( Milvus milvus) ++ + Short-toedEagle (Circaetusgallicus) + Bonelli's Eagle (Hieraaetusfasdatus) + ( Hieraaetuspennatus) + Golden Eagle (Aquila chrysaetos) + SpanishImperial Eagle (Aquila ( heliaca)adalberti) + Bearded Vulture (Gypaetusbarbatus) European Black Vulture (Aegypiusmonachus) Griffon Vulture ( Gypsfulvus) Egyptian Vulture ( Neophronpercnopterus) European Sparrowhawk( Acdpiter nisus) ( Acdpiter gentilis) +-4- Marsh (Circusaeruginosus) (Circuscyaneus) Montagu's Harrier (Circuspygargus) + (Fatcoperegrinus) + European (Fatcosubbuteo) + (Falco columbarius) + Eurasian Kestrel (Falco tinnunculus) +++ +++ ( Tytoalba) + ++ Eurasian Eagle Owl (Bubobubo) + ++ Long-earedOwl (Asiootus) + Short-eared Owl (Asioflammeus) + (Athene noctua) + (St*ix aluco) + + Total number dead under powerlines 567 686 1282 • D--Germany (Haas 1980), F--France (Striot and Rocamora 1992, Niebuhr pers. comm.), E--Spain (Haas 1980, Castanoand Guzman 1989, Mugica 1989, Negro and Manez 1989, Ferrer et al. 1991,Agrupacion Naturalista Esparvel 1993 and Segaraand Martos 1993). •' q- <5%, q-q- 5-10% and q-q- q- >10% of the total number of raptorsfound dead under powerlines.

Spanish Imperial Eagles found dead in Dofiana alonia and 82.6% in southern France (Real et al. National (Spain) were electrocuted.After iso- 1996). In the latter area where the total breeding lation or burial of powerlinesin 1987,juvenile sur- population is estimatedto consistof only 28 pairs, vival increased from 17.6% in 1986-87 to 80.0% in among 20 ringed juveniles found dead between 1988-89 (Ferrer and Hiraldo 1990). In northeast- 1990-95, 17 were killed on powerlines(Cheylan et ern Spain (Alicant, Murcia and Catalonia) and al. 1996). All Bonelli's Eagle populationsin north- southern France (Languedoc-Roussillonand Prov- eastern Spain and southern France are declining ence) powerlineswere responsiblefor 44.8% of the and, in some areas (Alicant and Murcia), the known mortalities of Bonelli's Eagles between abrupt decrease in population size seemsto be a 1980-93 (N = 58). The situation varied greatly consequence of high adult mortality through di- from one region to anotherwith only 5.2% of the rect persecution. In other areas (Catalonia and birds found dead in Murcia dying on powerlines southern France) where adult mortality is lower, as opposedto 38.0% dying on powerlinesin - the decline has been more moderate and has been MA•CH 1999 EXPANDED ABSTRACTS 45

Table 2. Percent of general avian mortality on electric powerlinesin "Important Areas" (1BAs)in the Plain of Crau and its vicinity (Bouches-du-Rh6ne,southeastern France), 1988-93.

TYPE OF BIRD A a B C raptors (/Strigiformes) 40.0 14.0 0.2 corvids () 45.0 10.3 0.5 and terns (Laridae) 3.0 15.9 61.6 herons (Ardeidae) 0.0 43.0 0.6 White Stork (Ciconia ciconia) 6.0 0.0 0.0 Greater Flamingo (Phoenicopterus ruber) 0.0 3.7 14.1 other birds 6.0 13.1 23.0 Total (N) 100 107 865 aA--electrocutions on medium voltage(<60 kV) distributionlines in the Plain ofCrau (IBA PAC 03) (Kabouche1991, Bayleunpubl data). B--electrocutions and collisionson medium voltage distribution lines in the Vigueirat marshes (IBA PAC 08) (Hecker et al 1992, Lucchesi unpubl. data). C--collisions on very high voltage (>150 kV) distribution lines in the saltworksof Fos-sur-Mer(IBA PAC 15) (Bayleunpubl. data). mainly a consequenceof and tors vulnerable (Deschamps 1980, Haas 1980, Sfir- high preadult mortality due to electrocution(Real iot and Rocamora 1992, Ferrer et al. 1993). The et al. 1996). problem is magnified when these powerlines tra- Raptors other than eaglesand vultures are also verse important raptor areas such as territories affected by powerlinesbut it is difficult to assess with important raptor breeding populations (e.g., the severityof the mortality since it varies greatly near vulture colonies) or terrains which attract from one population and geographicalarea to an- large numbers of birds of prey (e.g., hunting other. For example, powerlineswere responsible grounds such as marshlandsor ). For ex- for 22.6% of identified casesof mortality of Eur- ample, significantraptor mortality on medium volt- asianEagle in (Olsson 1979) and Fin- age lines has been recorded at Dofiana National land (Saurola 1979 in Mikkola 1983), 32.5% in Park in Spain (Haas 1980, Ferrer et al. 1991) and Germany (Wickl 1979), 54.7% in France (Bayle in southeasternFrance near the plain of Crau and 1992 and unpubl. data) and 16.3% in Spain (Her- its surroundings(marshes to the westand saltworks nandez 1989). In the southern Alps and Mediter- to the south). This area in France is a hunting ter- ranean area, the proportion of Eurasian Eagle ritory for Short-toed Eagles (Circaetusgallicus) in Owlskilled by powerlinesvaried from 45.5% in the the postnuptial period, a wintering area for Red Mediterraneanarea (N = 66) to 88.9% in the Alps Kites (Milvus milvus) and a major part of the ju- (N = 18). The "electrification" of landscapes venile Bonelli's Eagles in France use this area. seemsto be the major limiting factor of the alpine These sites have been classifiedamong the "Im- population of EurasianEagle Owls and may be the portant Bird Areas" (IBAs) according to Birdlife explanation for the decline of the speciesin the International standards (Rocamora 1994). They Swissand French Alps (Hailer 1978, Bayle 1992), are also close to denselyurbanized and industrial- as well as in the Italian Apennines (Penteriani and ized zones with considerable density of electric Pinchera 1991). lines of all types.This has resulted in a significant Powerlinestypically kill the smaller, more com- arian mortality for Black Kites and Short-toed and mon raptors (Table 1). In France, Eurasian Kes- Bonelli's Eagles (Tables 2, 3). trels are very frequent victims mainly becauseof PREVENTING RAPTOR PROBLEMS AT TRANSMISSION LINES massiveelectrocutions on certain medium voltage lines (Deschamps 1980, Brochet 1993). In one Before trying to prevent raptor problems at case,130 kestrels,one European Hobby (Falcosub- transmissionlines, the first step is to assessthe im- buteo),four Common Buzzards and 32 other birds pact of powerlineson these birds. This can only be were found in four years(1988-91) on a 5-km por- done by conductingthorough surveysunder pow- tion of a 20-kV powerline (Brochet 1993). erlines to determine which portions of the network Most powerli.nesare deadly becausethe config- are dangerousfor birds of prey. uration of structuresthat support them makesrap- Contacts must then be made with the power 46 EXPANDED ABSTRACTS VOL. 33, NO. 1

Table 3. Raptor mortality on electric powerlines in Im- plastic spirals) or by setting up frightening objects portant Bird Areas (IBAs) in the Plain of Crau and its on the poles (such as oversizedraptor silhouettes) vicinity (Bouches-du-Rh6ne,southeastern France), 1988- in order to drive the birds away from the lines 93. (Raevel and Tombal 1991). Different devices have been developed to reduce electrocution, either by SPECIES A a B C assuringa better isolation between electric wires (Buteo buteo) 5 3 0 and pylons (for example by isolating the wire or (Milvus migrans) 15 2 0 the pole with a plastic sheath) or by preventing Red Kite ( Milvus milvus) 1 0 0 birdsfrom perchingon electricpoles (Vereinigung Buzzard or kite (Buteo/Milvus) 3 0 0 Deutscher Elektrizitfitswerke1991). Pylonscan also Short-toed Eagle ( Circaetusgallicus) 5 5 0 be modified, especiallyto protect large raptors,by Bonelli's Eagle ( Hieraaetusfasciatus) 4 4 0 adding a specialperch above the wires. Short-toed or Bonelli's Eagle 1 0 0 All lines must be checked after they have been European Sparrowhawk( nisus) 0 0 1 equipped in order to test the efficiency of the de- Eurasian Kestrel (Falco tinnunculus) 3 1 0 unidentified falconiform 2 0 0 vices. For example, taper-like plastic poles which Long-eared Owl (Asiootus) 0 0 1 were placed on dangerouspylons around the col- EurasianEagle Owl (Bubobubo) 1 0 0 ony of reintroduced Griffon Vultures in the French Ctvennes National Park were inefficient and did Total (N) 40 15 2 not prevent the electrocution of two young birds •A-•electrocutions on medium voltage (<60 kV) distribution lines in the Plain of Crau (IBA PAC 03) (Kabouche 1991, Bayle which managed to perch between the obstacles unpubl. data). B•electrocutions and collisionson medium volt- (Terrassepers. comm.). age distribution lines in the Vigueirat marshes(IBA PAC 08) Although some European power companiesare (Hecker et al. 1992, Lucchesi unpubl. data). G--collisions on very satisfiedwith thesedevices and argue that they very high voltage (>150 kV) distributionlines in the saltworksof Fos-sur-Mer(IBA PAC 15) (Bayle and Iborra unpubl. data). reduce avian mortality by 90-95%, most of them can be consideredas only expedients.As far as me- dium voltage powerlines are concerned, an under- companiesto inform, sensitizeand convincethem ground network is the only totally efficient solution that it is necessaryto prevent raptor mortality on to raptor mortality. There are no technical prob- their networks.It is elusiveto expect that any type lems for the burial of medium tension lines and, of problem on powerlineswill be solved without at least in the small and denselypopulated Euro- the cooperation of the power companies. pean countries, the financial costs are equivalent Proposedmethods to reduce avian mortality on to those for the setting up of overhead lines. All powerlines must first be tested with mock poles voltage powerlinesin the Netherlands are under- and wires and slow motion film or video, either on ground and other westEuropean countriesintend captivebirds in speciallydesigned aviaries (studies to bury all their medium voltage lines in the near carried out in France by the "Union Nationale des future. At the beginningof the 1990s,77% of the Centres de Sauvegardede la Faune Sauvage") or transmissionlines in Belgium were alreadyunder- on trained birds in the field (Nelson and Nelson ground, 56% in (West) Germanyand 44% in the 1977), to see how the birds react to the devices. U.K., but south European countries such as Italy, This experimental phase is often overlooked by Franceand Spainare well behind with only 22%, power companies (mainly for financial reasons) 19% and 13%, respectively,of their mediumvolt- but is, by no means, superfluous.For example, in age lines buried (Vallet 1991, Anonymous 1993). France, 55 poles were equipped with a plastic,spi- These figures explain why the mortality of raptors ral prototype on a 5-km-long portion of a 20-kV on powerlines is so acute in the two latter coun- powerline to stop massiveelectrocutions of kes- tries, although other factors such as powerline trels; during the year that followed, 62 of kestrels configurationand raptor densitiesmay alsogreatly and one hobby were found electrocutedunder the influence the situation. The conservation com- supposedlyneutralized poles (Brochet 1993). munity must insistthat power companies (and gov- All powerline portions with high risksfor raptors ernments) undertake measures to enforce the must be modified to avoid avian mortality. On lines burial of the whole network in order to suppress where collisionsoccur this can be done by install- avian mortality on medium tension lines. In coun- ing warning deviceson the wires (such as colored tries such as France and Spain where so much still ]•d•CH 1999 EXPANDED ABSTRACTS 47 needs to be done, it cannot be reasonablyexpect- rapaces (et autres oiseaux) sur les lignes /t moyenne ed that all lines will be buried soon. Priority actions tension de la rfgion grenobloise.La Niverolle5:59-66. on problem powerlinesmust be determinedon a FERRER,M. ANDF. HIRALDO.1990. Evaluation of manage- national level between conservation groups and ment techniquesfor the SpanishImperial Eagle. Wild- life Soc.Bull. 19:436-442. power companies.In France, for example,the two , M. DE LA PdV^ANDJ. C^STaOVIEJO.1991. Electro- main bird protecting societies,the "Ligue pour la cution of raptors on power lines in southwestern Protection des Oiseaux" (LPO) and the "Fonds Spain.J. FieldOrnithol. 62:181-190. d'Intervention pour les Rapaces"(FIR) havelisted , G. JANssAND M.L. CHACON.1993. Mortalidad de eight priority bird species,among which are Os- avesen tendidoselectricos: situacion en Espana.Quer- preys (Pandionhaliaetus), Red Kites, Bonelli's Ea- cus 94:20-23. gles, Golden Eagles,Griffon Vultures and Eurasian GENSBOEL,B. 1984. Collins Guide to the birds of prey of Eagle Owls,as well asWhite Storks(Ciconia dconia) Britain and Europe, North and the Middle and Common Cranes (Grus grus). Conservation East. Collins, , U.K. measures should first be undertaken on lines that HAAS, D. 1980. Geffhrdung unserer Grossvtgel durch Stromschlag--eine Dokumentation. Oekol. Vb•el 2 lie acrossnatural landscapeswith large populations (Sonderheft):7-57. of raptors or which shelter endangeredspecies. HALLEa,H. 1978. Zur Populationstkologiedes uhus Bubo Such sitesare alreadylisted among IBAs and some- buboim Hochgebirge:Bestand, Bestandesentwicklung times protected as RamsarSites or as natural re- und Lebensraum in den RatischenAlpen. Orn. Beob. serves with a bird conservation vocation. LPO and 75:237-265. FIR have askedthe national power company"Elec- HECKER,N., A. IV[ANTEAND J.-L. LUCCHESI.1992. Etude tricit6 de France" (EDF) to cooperatein the estab- de la rfaction des oiseaux aux difffrents systkmesde lishment of a national action plan on these bases. visualisationde la ligne moyenne tension sur le do- To this date, EDF refusesto recognizethe need to maine du Vigueirat (commune d'Arles, Bouches-du- inventory priority zones. EDF concedestoday that RhCne). Station Biologiquede la Tour du Valat,Aries, France. preventing mortality on powerlines HEIJNIS,R. 1980. Vogelrod durch Drahtanflug bei Hoch- cannot be consideredanymore as a major techni- spannungsleitungen.Oekol. Vb•el 2 (Sonderheft.):111- cal problem (Vallet 1991). 129. HERNANDEZ, M. 1989. Mortalidad del buho real en Es- LITERATURE CITED pana. Quercus40:24-25. AGRUPACION NATURALISTA ESPARVEL. 1993. La electrocu- HOERSCHELMANN,H., A. HAACK AND D.F. WOHLGEMUTH. cion de rapacesen la provinciade Toledo. Quercus94: 1988. Verluste und ¾erhalten von Vtgeln an einer 24-29. 380-kV-Freileitung.Oekol. Vb•el 10:85-103. ANONYMOUS. 1993. La France en retard pour KABOUCHE,B. 1991. Une prospectiondes rfseaux 61ec- l'enfouissement des lignes. L•Environnement-Magazine triques de moyenne tension autour de St.-Martin-de- 1521:44. Crau (Bouches-du-Rhtne). CEEP, Aix-en-Provence, B^YLE,P. 1992. Le Hibou grand-duc Bubo bubodans le France. Parc National du Mercantour et ses environs. P.N. MIKKOLA,H. 1983. Owlsof Europe.T. & A.D. Poyser,Cal- Mercantour, Nice, France. ton, U.K. BROCHET,J. 1993. Expfrimentationdes prototypes spirale MUGICA, t. 1989. Aves electrocudas en la Comunidad de (SAAE) et Piver (RAYCHEM) sur les lignes EDF MT Madrid. Quercus39:29. 20.000 volts Compertrix--Haussimont (1991-92). NEGaO,JJ. ANDM. MANEZ.1989. Impacto de los tendidos LPO & EDF, Rochefort, France. sobre la avifauna. Quercus39:25-29. CASTANO,J.P. ANDJ. GUZMAN.1989. Mas de 70 rapaces NELSON, M. AND P. NELSON. 1977. Power lines and birds mueren electrocudas en dos tendidos electricas de of prey. Pages228-242 in Chancellorand Meyburg Ciudad Real. Quercus40:41. [EDS.], 1st World Conference on Birds of Prey, Vien- CHEYLAN,g., A. RAVAYROL,J.-M. CUGNASSE,J.-M. BILLET na, 1975, Berlin, Germany. ANDC. JOULOT.1996. Dispersiondes aiglesde Bonelli NEWTON,I. 1979. Population ecologyof raptors.Poyser, Hieraaetusfasciatusjuvfnilesbagufs en France.Alauda Berkhamsted, U.K. 64:413-419. OLSSON,V. 1979. Studieson a population of Eagle Owls COULOUMY,C. 1993. Causesde mortalit6 de l'Aigle royal Bubobubo (L.) in southeastSweden. Viltrevy11:1-99. en rCgion Provence--Alpes•CCte d'Azur. Faune & PENTERIANI,V. AND E PINCHERA. 1991. Densit6, distribu- Nature (Bull. ARPON) 35:9-13. tion et causesdu dfclin d'une populationde Hiboux DESCHAMPS,P. 1980. Point local sur l'61ectrocution des grands-ducs,Bubo bubo, dans les Abruzzes (centre de 48 EX?^NDED A•$XP,•CX$ VOL. 33, NO. I

l'Italie). RapacesNocturnes•Actes du 30e Colloque seau dectrique afrien. Analyse de la mortalit6 et so- interrfgional:189-193. lutions. LPO & EDF, Rochefort, France. RAEVEL,P. ANDJ.-C. TOMBAL.1991. hnpact des lignes TERRASSE,M., C. BAGNOLINI,J. BONNET,J.-L. PINNA AND haute-tension sur l'avifaune. Amgnagementet Environ- F. SARRAZIN. 1994. Reintroduction of the Griffon nement 1:1-56. Vulture Gypsfulvus in the Massif Central, France. REAl.,J., s. MANos& G. CHEY•N, P. BAVUE,J.-M. Ct:GN^S- Pages479-491 in B.-U. Meyburg and R.D. Chancel- SE,J.A. SANCHEZ,M.A. SANCHEZ,D. CARMONA,J.E. lor [EDS.], Raptor conservation today. World Work- MARTINEZ,L. Rico, J. CODINA, R. DEL AMO AND S. ing Group on Birds of Prey and Owls, Berlin, Ger- EGUIA.1996. A preliminaryapproach to the European many. Bonelli's Eagle population decrease in Spain and VALLET,G. 1991. D•veloppement des r•seaux souterrains France. Pages 523-528 in B.-U. Meyburg and R.D. HT en rural. Guide Technique de la Distribution Chancellor [EDS.], Eagle studies. World Working d'Electricit•, document A. 15-1. EDF GDF Services, Group on Birds of Prey and Owls, Berlin, Germany. Paris, France. ROCAMOV,&G. 1994. Les zones importantes pour la con- VEREINIGUNG DEUTSCHER ELEKTRIZITJ•TSWERKE. 1991. Vo- servation des oiseaux en France. LPO, Rochefort, gelschutzan Starkstrom-Frei-leitungenmir Nennspan- France. nungen fiber 1 kV, 2. Auflage. VWEW-Verlag,Frank- SEGARA,D. ANDJ.A. MAP,TOS. 1993. Trampa mortal en las furt-am-Main, Germany. lineas de alta tension.La Vanguardia18/09/93:8-9. WI(:I•L, K.-H. 1979. Der Uhu (Bubobubo) in Bayern. Gar- SEPaOT,J. ANDG. ROCAMOP,•.1992. Les rapaceset le r•- mischerVogelkundliche Berichte 6:1-47.