j RaptorRes. 39(1):70-74 ¸ 2005 The Raptor ResearchFoundation, Inc.

ABSENCEOF THE EURASIANGPdFFON (GYPSFULVU$) IN NORTHERN

Jost. R•ArL GARRIDO Departamentode Zoolog[a,C.E.S. Marcdo Spfnola-Universityof Wales,Plaza del Arzobispo1, 41806 Umbrete,Spain

ALV)mO C•dvnf4^ • Apartadode Correos339, 28220 Majadahonda,Madrid, Spain

MARIANGELA GUINDA AND MAPdA EGEA Departamentode Zoolog[a,C.E.S. Marcelo Spfnola-University of Wales,Plaza del Arzobispo1, 41806 Umbrete,Spain

NOURDINE MOUATI Ddpartementde Biologie,Facultd des Sciences, Universitd Abdelmaleh Essaddi BP2121 Tdtouan,Morocco

ALFONSOGODINO AND J.L. PAz DE LA ROCHA CalleCristo del Gallo 2, 23400•beda, Jagn, Spain

KEYWORDS: EurasianCaiffon; Gyps fulvus; t,'eeding range;, through this countrybefore reachingwintering grounds Morocco;wintering. in the southernSahara.

STUDY AREA AND METHODS The Eurasian Griffon (Gypsfulvus) is a Palearctic spe- cies distributed from North Africa, south and southeast- This studywas done in northern Morocco, from the ern Europe to the Middle East into southwesternand North Atlantic Coast (60 km north of K•nitra) to the central Asia (Cramp and Simmons,1980, del Hoyo et al. eastern Sahara Desert (Plateau du Rekkam) through the (Ouazzane-Chefchauoen-Ketama- to ) 1994). In the last three decadesthe Spanishpopulation and the Middle Atlas Mountains (from Mekn•s to ), has greatly increased (SEO BirdLife 1981, Arroyo et al. and from into Aln-Benimathar south as far as 1990, del Moral and Martl 2001). Migration of the spe- Bouarfa, near . The southernmostsurveyed point cies into Africa through the Strait of Gibraltar to Moroc- in central Morocco wasMekn•s. The studyarea is similar co and countries south of Sahara has been studied for a to the Spanish side of the Strait of Gibraltar from the long time (E16seguiand E16segui1977, Bernis 1983, ecological and geological points of view (Vald•s 1991) Alonso 1984, Griesinger 1998). However, there is limited Many large limestone mountains provide cliffs with suit- able caves and surfaces for Eurasian Griffons to breed recent information on the status of the speciesin Mo- (del Hoyo et al. 1994). On the Spanish side, one of the rocco.The information availableonly describesbreeding largestbreeding subpopulationsin Spain wasfound (del colonies documented in the past (Soto 1986, Bergier Junco and Barcell 1997,del Moral and Martf 2001). How- 1987). Mundy et al. (1992) referred to somecolonies in ever, on the Moroccan side there were breeding colonies the Rif Mountains closeto and additional ones only in the past (Soto 1986, Bergier 1987, Th•venot et from Figuig in the east to Goulimine on the westof the al. 2003). Some authors believe that griffons may still Anti-Atlas, with no breeding places in the Sahara Moun- breed there in Morocco, but the whole area has been tains. According to Haddane (1996) and others, the dis- heavilypopulated and hence changeddramatically (Had- dane 1996). tribution of griffons in Morocco has been reduced dras- Roadsidecounts covering ca. 2800 km were done dur- tically by human activities, and generally recent ing one entire month (1-28 February 2002). On those information (Mundy 2000, Thfvenot et al. 2003) wasnot dates, adult Eurasian Griffons are breeding (laying or in- supportedwith fieldwork. The extent of the population cubating) and non-adult migrating birds should still be decline of griffons and their winter distribution in Mo- on their wintering grounds (del Hoyo et al. 1994, pers rocco remain unknown. Our aim here is to: (1) survey obs.). Our surveywas done using a vehicle, at a speedof for the Eurasian Griffon breeding coloniesin northern ca. 40-50 km/h with stopswhen colonies were located Morocco and (2) analyze the recoveriesof ringed birds We looked for cliffswith raptor excrement (white wash), from Spain to identify potential wintering grounds. The aswell as perched and flying vultures (Fuller and Mosher 1981, Don/tzar et al. 1993). We searched for griffons at statusof the speciesin Morocco is relevant to its conser- any suitable cliff within view of our road surveysand at vanon. All migrating western European vultures cross potential feeding sitessuch as rubbish dumps or places where livestockcarcasses were dumped. During surveys, we used 10 x 40 binoculars and a 20-45x scope. We 1 Email address: [email protected] assumedthat our detectionprobability of the birdsfrom

70 MARCH 2005 SHORT COMMUNICATIONS 71 the road survey routes was very high. Detection of grif- fons is highly likely due to their large sizeand their flock- ing behavior in diffuse groups (Don•zar 1993). We also included supplementaryinformation collected at other sites during short-term visits throughout the typical breeding season(January-June). Additionally,we made 55 inquiries to local people who were familiar with the species,managers of the Moroccan Environment Agency,and foreign ornithologistswith a good knowledge of birds in Morocco. Photographsof both perched and flying griffonswere shownto local in- dividuals to help determine if they had seen these vul- tures. We also asked if these local residents knew of breeding colonies, if they had seen griffons on a year- round basis,and if so, when, where, and how many birds they had seen. Also, we inquired about the attitude of people toward griffons and other raptors. Finally,to completeour assessmentofEurasian Griftbn Figtire 1. Map of Morocco showing the recoveries of status in Morocco we examined all the recoveries of birds Griffon Vultures ringed in Spain (numbers as in Table ringed in Spainfrom 1965-2002.The followingdatabases 1) and locations of reported observations of griffons were reviewed: Centro de Migraci0n de Aves (SEO/ (0)- The study area in northern Morocco is outlined. BirdLife), Direcci6n General de Conservaci6n de la Na- turaleza (DGCN) from the SpanishMinistry of Environ- ment, and Museo de Ciencias Aranzadi from San Sebastian. the studyarea, plus one in the easterndesert and anoth- er in the Atlas Mountains (Fig. 1). All were made on the RESULTS Mediterranean side of Morocco and in the Rif Moun- tains. People interviewed said that groups of vultures We did not see any griffons during the roadsidecensus were never seen for long periods. The mean group size or breeding at any previously-reportedcolonies. We was 6.5 ___6.2 (SD) griffons (range = 1-73). Further- searched for colonies, but found none in theJebel Mous- more, no information was reported on recent breeding sa in Tangier region, the Jebel Bouhachen Nattire Re- colonies.Only one record involvedgriffons feeding on a serve, and Jebel Haouz (Soto 1986). We surveyedBab carcassnear Tangier. Observationswere sparselydistrib- Taza, visitingTissouka, Lahkraa, Jebel el-Kelaa,Jebel Ab- uted throughout the year: five in winter (December-Feb- doune, and Talambote, as well as the Oued Laou can- ruary), seven in spring (March-May), four in summer yons. We also passedthrough TalaseemtaneNational (June-August), and three in autumn (September-No- Park and the Ketama (Jebel Tidiquim) Mountains sur- vember). Observers provided six records (20.8%) for rounding de Targuist and Al-Hoceima National Park, which they could not recall the season.Everyone inter- close to the coast. In addition, we visited the Middle Atlas viewedpointed out that griffons, aswell as other raptors, at Tazzeka National Park. Other colonies mentioned by were shot and even consumed by man. Moreover, five Soto (1986) and visited with negative resultswere Bou older residents remembered the species from their Bgar (Gorges de la Moulouya), nearby Oujda city. Fur- youth, when wild ungulatesand big felids, such as lions thermore, two recorded colonies in Massif des Beni Snas- ( Pantheraleo) or leopards ( Pantherapardus), inhabited the sen had no griffons. Our lack of detectionssuggests that area. These individualsreported that griffons were pres- there were neither breeding nor wandering birds in the ent in the 1960sand 1970s.Finally, one observerreport- studyarea. During our roadsidecounts we easilydetected ed six griffons in the Middle Atlas Mountains (near severalcliff-nesting raptors such as Bonelli's Eagles (Hi- Azrou), although he wasunable to recall the date and if eraaetusfasciatus), Peregrine Falcons (Falcoperegtinus), they were migrant or resident. Bedouin shepherds indi- and Golden Eagles (Aquila chrysaetos),all more difficult cated that every winter a small griffon population re- to detect than Eurasian Griffons. Therefore, we believe mains in the desert located in the Eastern Atlas Moun- that we did not overlook the latter species.Two rubbish tains, where there is a winter food supply from sheep dtanps were visited, one south of Tangier and another carcasses. close to Chefchaou&n to the east. None of these seemed We found only nine recoveriesof Spanishringed grif- to support griffons, although there were large numbers fons in diffkrent locationsof Morocco (Fig. I and Table of White Storks (Cic0nia ciconia).Our previous visits to 1). Most of them (except recoveries8 and 9) were ringed Morocco had revealedno griffonsin the L'Oum or Rbia as nestlings, but all were probably ringed as juvenile and E1Menzel coloniesin 1986 and 1994, respectively. birds. Where information was available, most of the Of 55 questionnaires,only 50 were judged to provide deaths were attributed to malnutrition (Table 1). Three valid information. Basedon their reports, 26 respondents had died recently,two were sightedalive, and a sixth grif- observed Eurasian Griffons in the last decade, 24 within fort was maintained in captivity.It is noteworthy that all 72 SHORT COMMUNICATIONS VOL. 39, NO. 1

Table 1. Recoveriesof ringed Eurasian Griffons in Morocco. Dates (ca. dates are in parentheses),coordinates of ringing and recoveryare also shown.

RECOV- ERY COORDI- PROVINCE CIRCUMSTANCES COORDI- NUM- AGE OF DATE OF NATES OF OF OF DATE OF NATES OF LOCATION OF BER RINGING RINGING RINGING RINGING RECOVERY RECOVERY RECOVERY RECOVERY

I Nestling 25 Jun 67 42.55N Navarra Captured 02 Nov 70 33.47N SoukKhemis 01.51W 06.02W Ait Yadine 2 Nestling 19 May 71 42.38N Huesca na 01 Dec 72 33.16N Timandite 00.49W 05.05W 3 Nestling 12 May 79 40.56N Teruel Corpsealone 02 Oct 80 30.29N Taroudant 00.15W found 08.52W 4 Nestling 29 May 84 36.35N Cfidiz 29 Nov 84 33.50N Khemisset 05.50W na 06.03W 5 Nestling 11 May 85 41.21N Segovia 06 Jun 86 33.15N Jori Lasfar 03.50W Malnutrition 08.40W 6 Nestling 10 May 86 41.29N Soria Predated 06 Jul 87 30.30N Toulgharb 09.40W 09.40W 7 Nestling 18 May 96 42.50N Alava na 24 Feb 98 35.53N Ceuta 03.06W 05.19W 8 na 27 Nov 98 37.00N Huelva na 07 Jan 99 32.16N Rich 06.30W 04.30W 9 Fledgling 10 Sep 99 41.34N Burgos Malnutrition 19 Nov 99 34.57N Midar 03.41W 03.33W

nine griffonswere ringed in different Spanishprovinces. 2001 (P. Bergier pers. comm.). To date, the migration Finally,three were ringed in the 1960sor 1970s,four in period and pattern of griffons has not been analyzed in the 1980s, and four in the 1990s, with no increases in detail (Bernis 1983, Franchimont and Moumni 1996, recoveriesdespite the increasesof both the Spanishpop- Griesinger 1998). Migration phenology in the Strait of ulation and the number of griffons ringed (del Moral Gibraltar area extendseven later than October,with large and Mart/ 2001, G6mez-Manzaneque et al. 2002). numbersstill passingin November (SEO/BirdLife 2001). Ring recoveriesof griffons were scarceand were not DISCUSSION adequate to draw any conclusions.Recent studies with Our survey revealed a complete lack of breeding or EgyptianVultures (Neophronpercnopterus) tracked with sat- wintering Eurasian Griffons in northern Morocco. This ellite transmitters (Benitez et al. 2003, M. de la Riva pers. could reflect the alarming decline of the speciesreported comm.) showedbroad-band migration over Morocco and by Soto (1986) and Thrivenotet al. (2003). Accordingto that the birds followed a straight flight path southwards theseauthors and this current study,the EurasianGriffon over the country and the SaharaDesert. Limited data for could be extirpated as a breeding speciesin this region griffons seem to show a similar migration pattern, al- and probably in all of Morocco. Reasonsfor this decline though it has been suggestedthat these vultures follow would be lack of food and direct human persecutionby specificroutes as they do in Spain (Garrido et al. 2001). means of poaching and poisoning (Soto 1986, Haddane Recoveriesof griffons on the Atlantic side could suggest 1996, Thrivenot et al. 2003). The same reasons could ex- a second coastalroute or vagrant birds. Migration along plain why there are no vagrant griffons in the area, de- this route would likely take griffons to sub-Saharanwin- spite that the physicalhabitat appearssuitable. Results of tering quarters in Mauritania, Senegal, and Mali (del inquiries indicated that only migrating griffons from Eu- Hoyo et al. 1994, Layna 1999). A smallgriffon population rope passedover northern Morocco, and that no locally- could remain in the northern Sahara, if food is available. breeding birds were present. Increasing numbers of grif- In addition to Spanish recoveries,there is another from ions have been recorded crossinginto Africa in recent a juvenile griffon ringed in the Pyreneesof France as a yearswith 1633, 2649, and 4816 birds in 1998, 1999, and nestling in early June 1993 and recoverednear Meknas 2000, respectively(SEO/BirdLife 2001). Furthermore, within the sameyear (5 October; Arthur and Peyrusque up to 1524 were recorded at Koudia el Baida (20 km 2000) that supportsthe idea of a central broad-bandmi- north to Tetouan and 30 km east from Tangier), with gration of griffons.The percentageof ring recoveriesin 1426 birds counted on 23 October during a surveyin Morocco (2.7%) is lower than that in the Iberian Pen- •IARCH 2005 SHORT COMMUNICATIONS 73 lnsula (5.1%), from 4062 griitbns ringed in Spain (G6- vice scientifiqueN ø 99/08/GR, Parc National des Pyr- mez-Manzanequeet al. 2002). Probabilitiesof reporting en6es, Ossau, France. a ringed bird could be biased relativelyhigh in heavily BENiTEZ, J.R., J.A. SANCHEZZAPATA, J.A. DON•.ZAR, populated areas, giving a misleadingimpression of the M. DE LA RIVA, F. HERN•,NDEZ, AND M. BARCELL.2003. migration route. Nevertheless,the final destinationof Andalucia se queda sinAlimoches. Quercus 206:15-19. griffons should be determined by future studiesusing BERGmR,P. 1987. Les rapacesdiurnes du Maroc. Status, satellite transmitters (Camiria, 2004). r6partition et ecologie. Centre d'Etudes sur les Eco- From the conservationpoint of view, our study indi- syst•mesde Provence,Aix en Provence, France. cates that the Eurasian Griffon is seriouslyendangered, BERNIS,E 1983. Migration of the common griffon vulture if not extinct as a breeding speciesin Morocco. The de- in the western Palearctic. Pages 185-196 in S.R. Wil- cline in the griffon population wasprobably due to a lack bur andJ.A.Jackson lEDS.], Vulture biologyand man- of available food and human persecution. For this rea- agement. Univ. California Press,Berkeley, CA U.S.A son, we suggestthat it is urgent to examine the statusof CAMIS•A,A. 2004. Griffon vulture Gypsfulvus monitoring the griffons in Morocco and other African countries in Spain: current researchand conservationprojects. south to the Sahara to provide information necessaryto Pages 45-66 in R.D. Chancellor and B.-U. Meyburg implement conservationmeasures. lEDS.I, Raptorsworldwide. World Working Group on Birds of Prey and Owls and BirdLife Hungary, Buda- AUSENCIA DE GYPS FULVUS DEL NORTE DE MARRUECOS pest, Hungary. CRAMP,S. AND K.E.L. SIMMONS(EDS.). 1980. The birds of RESUMEN.--Mediantetransectos por carreteraen el norte the western Palearctic. Vol. 2. Oxford Univ. Press, Ox- de Marruecos (2800 km) y visitasa antiguascolonias de ford, U.K. cria, se han buscado evidencias de cria o invernada del DEL HOYO,J., A. ELLIOTT,AND J. SARGATAL.1994. Hand- bultre Gypsfulvus.Adem/ts, se han realizado55 encuestas book of the birds of the world. Vol. 2. Lynx Edicions, a habitantesde Marruecos sobre el estatusde la especie. Barcelona, Spain. No se ha encontrado ningfin buitre criando a pesar del DELJUNCO, O. ANDM. BARCELL.1997. E1 buitre leonado aparente h•tbitat disponible. Los habitantesde la zona (Gypsfulvus)en Cftdiz.Junta de Andalucia, Consejeria indicaron su presenciaen el pasado.La persecuci6nhu- de Medio Ambiente, C•tdiz,Spain. mana puede ser la causade esterdisminuci6n. A1 menos DEL MORAL,J.C. AND R. MARTi (EDS.). 2001. E1 buitre en el •rea de estudio la especie esta extinta como nidi- leonado en la Peninsula Ib•rica. SEO/BirdLife, Ma- ticante. Las recuperacionesde avesanilladas son escasas drid, Spain. y se concentran en tres zonas: el desierto del este, las DONAZAR,J.A. 1993. Los buitres ib•ricos: biologia y con- montarias centrales y la Costa Atl•tntica de Marruecos. servaci0n.J.M. Reyero Ediciones,Madrid, Spain. Son necesariasurgentes investigacionessobre el estado , O. CEBALLOS,A. TRAVAINI, AND E HIRAI,DO. 1993. del buitre G. fulvus en todo el pais. Roadsideraptor surveysin the Argentinean Patagon- [Traducci6n de los autores] ia.J. RaptorRes.27:106-110. ELOSEGUI,J. ANDR. ELOSEGUI.1977. Desplazamientosde ACKNOWLEDGMENTS buitres comunes(Gyps fulvus) pirenaicos.Munibe 29 97-104. The travel was financed by Centro de EstudiosSuper- iores,Marcelo Spinola Universityof Walesfrom Umbrete FRANCHIMONT,J. ANDT. MOUMNI. 1996. Suivi partiel de (Sevilla). Adolfo Rodriguez, Juan Jos6 Ramos Encalado, la migration post-nuptiale des rapaces diurnes sur la Angel G6mez-Manzaneque,and PatrickBergier provided rive du sud du d6troit de Gibraltar en 1995. Porphyno us with useful observations.Colin Pennycuickand Fiona 8:55-76. Grant from Free Spirit Films (Bristol) greatly improved FULLER,M.R. ANDJ.A. MOSHER.1981. Methods of detect- the English text. Peter Mundy and the editor provided ing and counting raptors: a review. Stud.Arian Biol. 6' helpful commentson an earlier draft of the manuscript. 235-246.

LITERATURE CITED GARPaDO,J.R., A. CAMff•A,M. SURROC•,AND J. MOTTOS. 2001. Migration of the Eurasian Griffon Vulture ( Gyps ALONSO,J.C. 1984. Sur les quartiers d'hiver des vautors fulvus) through the Iberian Peninsula. Raptor Re- fauvesmigrateurs. Alauda 52:308-309. search Foundation and Estaci6n Bio16gicade Dori- ARROYO,B., E. FERREIRO,AND V. GARZA.1990. Segundo ana, Sevilla, Spain. censo nacional de buitre leonado (Gypsfulvus): pob- G6MEZ-1VIANZANEQUE,A., E HERN•DEZ-CARRASQUILI.A,O. laci6n, distribuci6n, demograf/a y conservaci6n.Co- CORRAL,AND R. MORENO-OPO. 2002. Informe sobre la lecci6n T6cnica, Instituto Nacional para la Conserva- campariade anillamiento de avesen Esparia.Ecologia ci6n de la Naturaleza, Madrid, Spain. 16:343-376. ARTHUR,C.P. ANDD. PEYRUSQUE.2000. Compte-rendu de GRIESINGER,J. 1998. Juvenile migration and dispersion l'operation 1999 de marquage de vautours fauves among griffon vultures Gypsfulvus in Spain. Pages dansla reservenaturelie d'Ossau.Rapport PNP/Ser- 613-622 in B.-U. Meyburg,R. Chancellor,andJJ. Fer- 74 SHORTCOMMUNICATIONS VOL. 39, No. 1

rero [EDS.], Holarctic birds of prey: proceedings of SOCIEDAD ESPAlqOLA DE ORNITOLOGiA/BIRDLIFE. 1981 an international conference. World Working Group Primer censo nacional de buitreras. Ardeola 26-27' on Birds of Prey and Owls, Badajoz,Spain. 165-312. HADDANE,B. 1996. The impact of human activitiesand --. 2001. Seguimiento de la migraci0n en el estre- rehabilitation of raptors:case study, current situation cho, afio 2000. Consejer/ade Medio AmbienteJunta of raptors in Morocco. 2nd International Conference de Andalucia y Sociedad Espafiola de Ornitologia, on Raptors 1996, The Raptor Research Foundation Madrid, Spain. and the University of Urbino, Urbino. Italy. SOTO,P. 1986. Le statut du vautour fauve Gypsfulvusau L•YNA,F.J. 1999. EurasianGriffons Gypsfulvusmigrating maroc.Birds Prey Bull. 3:173-181. into Cap Blanc, Mauritania, Western Sahara. Vulture THIeVENOT,M., J.D.R. VERNON,AND P. BERGIER.2003. The News 36:35-36. birds of Morocco. British Ornithologists'Union, Lon- MUNDY,P. 2000. The statusof vultures in Africa during don, U.K. the 1990s. Pages151-164 in R.D. Chancellor and B.- VALDgS, B. 1991. Andalucia and the rif, floristic links and U. Meyburg [EDS.], Raptors at risk. World Working common flora. Bot. Chron. 10:117-124. Group on Birds of Prey and Owls, Berlin, Germany. --, D. BUTCHART,J. LEDGER,AND S. PIPER.1992. The vultures of Africa. Academic Press, London, U.K. Received3 July 2003; accepted8 December 2004

j RaptorRes. 39(1):74-79 ¸ 2005 The Raptor Research Foundation, Inc.

ARTIFICIAL NEST STRUCTURE USE AND REPRODUCTIVE SUCCESS OF B)•V,N OWLS IN NORTHEASTERN ARKANSAS1

P^ULM. IL•LF•Y2 •_NDJ^MFS C. BF•DN•a•Z Departmentof BiologicalSciences, PO. Box 599, ArhansasState University, State University, AR 72467 U.S.A.

KEYWORDS: Barn Owl;Tyto alba pratincola; artificialnest- abundant.At thissite, Marti et al. (1979) surveyedca. 50 ing structures;breeding chronology; reproductive success; pro- silosthat were used as roostsby Barn Owls,but only one ductivity;Arkansas. provided a suitable nest site. In 1977, these workers placed nest boxes in 30 silos before the spring nesting Raptor numbers and productivity in some regions are period.By the end of 1978,24 (80%) of the boxeswere clearlylimited by availabilityof nestsites (Newton 1979). usedby breedingowls (Marti et al. 1979). Similarly,on A shortage of nest sitesmay hold raptor populations at a oil palm (Elaeisguineensis) plantations in Malaysia,Duck- breeding densitybelow the level that food would other- ett (1991) reported that breeding population densitiesof w•sesupport (Newton 1979). There are two typesof evi- the Barn Owl (T. a. javanica) were limited by available dence in the literature that support this hypothesis:(1) nest sites,despite high densitiesof severalspecies of rat breeding pairs are scarce in areas where nest sites are (Rattusspp.; ca. 250-400/ha). Twentymonths after Duck- absent (but which seem otherwise suitable), and (2) the ett (1991) erected 200 nest boxes in a 1000 ha mature provision of artificial nest sites is often followed by an palm plantation (1 box/5 ha), 95% were occupiedby increasein breedingdensity (Newton 1979). nestingBarn Owls. As a result, rat damageto palm trees Studies done on Barn Owls (Tyro alba) in northern on the plantation had dropped by 18.1% from the be- Utah by Marti et al. (1979) supportsNewton's (1979) ginning of the study (Duckerr 1991). The studies con- proposal concerning the effect of limited nest sites.Marti ductedby Marti et al. (1979) and Duckerr(1991) support et al. (1979) suggestedthat prior to the appearanceof the hypothesisthat Barn Owl populationscan be limited buildings, a breeding population of Barn Owls was vir- by the availabilityof nest sites. tually nonexistent on his studyarea due to a paucity of Bloom and Hawks (1983) recorded similar resultsby suitablenest sites, but that foraginghabitat and preywere testing nest-site limitation in American Kestrels (Falco sparverius)in northern California. Of a total of 208 nest • The editorial processingand reviewof this paper were boxesexamined between 1977-80, 31% were occupied handled by Clint W. Boal. by breeding kestrels (Bloom and Hawks 1983). Bloom 2 Email address:[email protected] and Hawks (1983) suggestedthat with more strategic