148 SHORT COMMUNICATIONS VOL. 36, NO. 2

LITERATURE CITED tats of Chile, Spain, and California: a comparativeap- proach. Am. Midl. Nat. 107:151-162. AGUIRRE,L.E ANDS. ANDERSON.1997. Clave de campo MARTI,C.D., E. KORPIMAKI,AND EM. Jpacslc.1993. Trophic para la identificaci6n de los murci61agosen Bolivia. structureof raptor communities:a three-continentcom- Serie Zoologia No. 5, Instituto de Ecologia,La Paz. parisonand synthesis.Curz. Ornithol. 10:47-137. ANDERSON,S. 1997. Mammals of Bolivia:taxonomy and MIES, R., A. KURTA,AND D.G. IgJNG.1996. Eptesicusfun- distribution. Bull. Am. Mus. Nat. Hist. 231:1-652. nalis.Mamm. Species526:1-7. BRACE,R.C., J. HORNBUCKI.E,AND J.W. PEARCE-HIGGINS. MOTrA-Jt)NIOR,J.C. ANDV.A. TADDEI.1992. Batsas prey 1997. The avifaunaof the Beni BiologicalStation, Bo- of the StygianOwl in southeasternBrazil. J. RaptorRes livia. Bird Conserv. lnt. 7:117-159. 26:259-260. EISENBERG,J.E ANDK.H. REDVORD.1999. Mammals of the MUSSER,G.G., M.D. CASTLETON,E.M. BROTHERS,•ND A.L. neotropics.Vol. 2. The central neotropics:Ecuador, GARDNER.1998. Systematicstudies of oryzomine ro- Peru, Bolivia,Brazil. Univ. of ChicagoPress, Chicago, dents (Muridae, Sigmodontinae):diagnoses and dis- IL U.S.A. tributions of speciesformerly assignedto Oryzomys GERHARDT,R.P., D.M. GERHARDT,C.J. FIATFEN,AND N.B. "capito".Bull. Am. Mus. Nat. Hist. 236:1-376. GONZALEZ.1994. The food habits of syrupatticCiccaba RUPRECHT,A.L. 1979. Bats (Chiroptera) as constituents owlsin northern Guatemala.J. FieldOrnithol. 65:258-264. of the food of Barn Owls Tytoalba in Poland.Ibis 121: HERRERA-MACBRYDE,O., F. DALLME1ER,B. MACBRYDE,J.A. 489-494. COMISKEY,AND C. MIRANDA lEDS.]. 2000. Biodiversi- TAYLOP,,I. 1994. Barn Owls.Predator-prey relationships and dad, conservaci6ny manejoen la regi6n de la Reserva conservation.Cambridge Univ. Press,Cambridge, U.K. de la BiosferaEstaci6n Bio16gica del Beni, Bolivia.SI/ WILSON,D.E. AND R.K. LA VAL. 1974. Myotisnigricans MAB SeriesNo. 4. SmithsonianInstitution, Washing- Mamm. Species39:1-3. ton, DC U.S.A. JAKSIC,EM., R.L. SEro,AND C.M. HEPmERA.1982. Preda- Received 23 December 2000; accepted 22 November tion of Barn Owl (Tyt0 alba) in mediterraneanhabi- 2001

j RaptorRes. 36(2):148-152 ¸ 2002 The Raptor Research Foundation, Inc.

FOOD OF THE LESSERKESTREL (FALCO NAUMANNI) IN ITS WINTER QUARTERSIN SOUTHAFRICA

GRZEGORZKOPIJ 1 Departmentof Biology,National Universityof Lesotho,P.O. Roma180, Lesotho

KEYWORDS: LesserKestrel; Falco naumanni; winterquar- (Siegfriedand Skead 1971, del Hoyo et al. 1992). A dras- ters;; diet;,Solifugae. tic decline in wintering LesserKestrels was also noted in this province,where ca. 74 000 birds were recorded dur- The LesserKestrel (Falco naumanni) has undergonea ing the australsummer of 1966--67(Siegfried and Skead drastic decline in this century in its breeding range in 1971) and only 33900 during the austral summer of the southern Palearctic and is classified as RARE in the 1992-93 (Roosand Roos1986, Colahah 1993). Preycon- RedData Book(del Hoyo et al. 1992, Tucker and Heath taminated by pesticidesand the destruction of natural 1994). At present, 6000-10 000 breeding pairs occur in habitatsin the LesserKestrel's breeding range have been Europe (Gonzalezand Merino 1990). Recently,the great- suggestedas the main factorsresponsible for the decline est density of breeding Lesser Kestrelswas reported in (del Hoyo et al. 1992, Tucker and Heath 1994). Spain,where an estimated20 000-50 000 breeding pairs Food availabilityis one of the most important ultimate •n 1980 had fallen to 4200-5100 by 1990 (Tucker and factorscontrolling any avian populationand information Heath 1994). on the diet of a declining species,such as the Lesser The LesserKestrel is migratoryand most individuals Kestrel, is therefore vital for conservation. Summer diet winter in the grasslandsof the Free Statein SouthAfrica of the LesserKestrel has been investigatedquantitatively in Spain, France, and Austria (Cramp and Simmons 1980, Bijlsma et al. 1988). The diet in winter has been Present address: R.aczka 13, 49-137, Korfantow, Poland. examined through the analysisof stomachcontents (An- JUNE 2002 SHORTCOMMUNICATIONS 149 derson et al. 1999, Kok et al. 2000). In this paper, I pre- thopteransand beetleswere alsoan important component, sent data on the Lesser Kestrel diet as determined by togetherforming 27.5% of the totalnumber of preyitems analysisof pelletscollected in SouthAfrican grasslands. identifiedand 44.4%of the totalwet biomass(Table 1, Fig 1). Orthoptera were mainly representedby grasshoppers METHODS (Orthoptera:Acrididae), while beetlesmainly by scarabae- The food of the LesserKestrel was determined by anal- ids.Other arthropodgroups, such as earwigs, termites, cock- ysis of pellets. Most pellets were collected between No- roaches(Blattodea), dragonflies, and scolopendrasconsti- vember1997 and February1998 from a traditionalroost- tuted supplementaryfood (Table 1). Only a few vertebrate lng site in a stand of large eucalyptus(Eucalyptus sp.) in itemsrepresented by smallmammals were found (Table 1) Oosteinde, , South Africa (29ø10'S, Three pelletscontained small stones. 26ø15'E). About 2000 Lesser Kestrels roosted there from late October1997 to earlyMarch 1998.A few pelletswere Sun spiders were especially numerous in the Lesser also collected in four other traditional roosting sites (in Kestrel'sdiet in November-December, being recorded in large eucalyptus)in the :at Winburg (27ø01'S, each pellet examined (Fig. la), and formed over 80% of 28ø30'E),70 km NE of Bloemfontein(25 pelletscollected the total wet biomassconsumed (Fig. lc) and over 70% on 22 November 1997), at (29ø39'S, of total prey items consumed (Fig. lb). Out of 105 and 26ø10'E),40 km S of Bloemfontein(100 pelletscollected 275 pellets selectedrandomly from November-Decem- on 26January1998), at Edenburg(29ø43'S, 25ø55'E), 15 ber (100% of which containedsun spiders) and January- km SW of Edenburg (74 pelletscollected on 5 January February (49% containedsun spiders),respectively, the 1998), and at (30ø02'S, 25ø43'E), 23 km SW mean number of sun spidersper pellet decreasedsignif- of Edenburg (85 pellets collected on 5 January 1998). icantly (t = 4.10, df = 26, P = 0.005) from November- The natural vegetation around Winburg is represented by the Cymbopogon-ThemedaVeld, while the False Upper December (i = 8.87, SD = 25.34, range = 1-17, N = Karoo is the natural vegetationat the other sites.Most of 105) to January-February(i = 1.40, SD = 8.68, range = the natural vegetation around all four sites has been, 0-10, N = 275). however, converted into cultivated fields. The quantityof sunspiders consumed by the LesserKes- The rainfall during November-December1997 was trel in Bloemfontein,as reflected in the randomly-selected much lower (50 mm), while during January-February pellets containing sun spiders (Fig. 3), decreasedas the 1998 much higher (420 mm) than long-term (40 yr) av- winteringseason progressed (X 2 = 98.79, P < 0.01, df = erage for theseperiods (ca. 140 mm for November-De- 3). In contrast,the proportion of pelletscontaining beetles cember and ca. 170 mm forJanuary-February). significantlyincreased (X 2 = 47.49,P < 0.01, df = 3), and Only fresh and compact pellets were collected in the middle and at the end of each month of the study.Each Orthopterans were more frequently found in pellets •n pellet was broken apart by hand and remains of prey January-Februarythan in November-December(X • = items were identified mainly to the level of order. The 43.22, P • 0.01, df = 3; Fig. la). Similarly,the frequency following prey remains were isolated for identification: with which other prey, such as earwigs, termites, small chelicerae of sun spiders (Solifugae), exoskeletons,jaws mammals etc., were taken increased toward the end of the and elytrae of orthopterans (Orthoptera) and beetles winteringseason (X • = 11.86, P • 0.01, df = 3; Fig. la) (Coleoptera), cerci of earwigs(Dermaptera), headsand Sun spiderswere equallycommon at other localitiesin wings of termites (Isoptera), and hair of small mammals the Free State (Fig. 2), being found in almostevery pellet (Micromammalia). collected(X • = 3.49, P > 0.05, df = 7). The contribuuon Frequencyof occurrencewas calculated as the propor- tion of the total number of pellets examined containing of orthopteranprey decreasedsouthward, i.e., from wetter a given taxon. Estimation of prey number and their wet to drier areas (X• = 23.28, P • 0.005, df = 7), while the biomassin the pellets was based on the following as- contributionof beetlesand other preygroups to the falcon's sumptionsand calculations(wet biomassof prey X mean diet (Fig. 3) wasmarkedly different from site to site (X2 = number of prey per pellet): sun spiders,1.4 g X 8.5 in 112.6, P < 0.001, df = 7 and X• = 21.86, P < 0.005, df = November-December, 1.4 g X 2.5 in January-February; 7 for beetlesand other preygroups, respectively). orthopterans1.4 g X 2; crickets(Orthoptera: Gryllidae), 1.4 g X 1; beetles,0.7 g X 2; scarabaeids(Coleoptera: DISCUSSION Scarabaeidae),0.7 g X 2; ground beetles (Coleoptera: Carabidae), 0.3 g X 2; tenebrionids(Coleoptera: Tene- During the breeding season,beetles and grasshoppers brionidae), 0.3 g X 2; termites, 0.1 g X 10; earwigs,0.1 constitute the bulk of the Lesser Kestrel diet, supple- g X 2; dragonflies (Odonata), 1.0 g X 1; scolopendras mented by a low frequency of large prey, such as small (Chilopoda: Scolopendromorpha),2.0 g X 1; small in- mammals, lizards (Sauria), bush crickets (Orthoptera. sectivorousmammals (Mammalia: Insectivora), 10 g X 1; Tettigonidae), and mole crickets (Orthoptera: Gryllotal- small mammals, 20 g X 1. pidae) (Cramp and Simmons1980, Bijlsmaet al. 1988).

RESULTS In South Africa, these larger prey groups are replaced mainly by smaller sun spidersand termites,while verte- A total of 2050 pelletswas collectedfrom November brate prey are taken only occasionally(Anderson et al. 1997-February1998. The LesserKestrel's diet during the 1999, Kok et al. 2000). non-breedingseason was dominated by sun spiders.Or- Pellet analysiscan underestimate the contribution of 150 SHORT COMMUNICATIONS VOL. 36, NO. 2

Table 1. Food of Lesser Kestrelswintering near Bloemfontein, Free State, South Africa. Data are from pellets col- lected from November 1997 through February 1998.

FREQUENCYOF APPROXIMATENUMBER APPROXIMATEWET BIOMASS OCCURRENCE OF PREY OF PRFY

TAxA N % N % GRAMS %

Arachnida Solliihgae 1695 82.6 11 558 68.3 16 180 75.0 Insecta Orthoptera 1478 69.9 2815 16.6 3950 18.3 Combined Gryllidae 141 6.9 141 0.8 200 0.9 Other Orthopterans 1337 63.0 2674 15.8 3750 17.4 Coleoptera 1033 50.4 2003 11.9 1175.5 5.5

Combined Scarabaeidae 550 26.8 1100 6.5 770 3.6 Cetoniinae 41 2.0 50 0.3 35 0.2 Car abidae 117 5.7 234 1.4 70 0.3 Tenebrionidae 45 2.2 60 0.4 20 0.1 Curculionidae l 0.1 I <0.1 0.3 <0.1 Unidentified Coleopterans 279 13.6 558 3.3 280 1.3 Dermaptera 35 1.7 70 0.4 7 <0.1 Isoptera 33 1.6 330 2.0 35 0.2 Blattodea 4 0.2 4 <0.1 1 <0.1 Odonata 2 0.1 2 <0.1 2 <0.1 Chilopoda Scolopendromorpha 21 1.0 30 0.2 60 0.3 Mammalia 7 0.3 7 <0.1 140 0.6

Micromammalia Insectivora 1 0.1 I <0.1 10 <0.1 Small stones 3 0.2 20 0.1 10 <0.1 Total 2050 16 915 100 21 570 100

termite alates and scolopendras to the Lesser Kestrel's a small proportion of the LesserKestrel diet in this study &et, if the hard body parts (heads,wings) are not well On the basisof pellet analysis,Van Zyl (1993) showeda preserved in pellets. Anderson et al. (1999) and Kok ct summer peak of sun spidersand winter peak of orthop- al (2000) showed a much higher proportion of these terans in the diet of Eurasian Kestrels (Falco tinnunculus) prey groups than I found in the diet of the Lesser Kes- in South Aridca. trels wintering in the Bloemfontein area. The prevalence The importance of orthopterans in the diet of the Less- o1 sun spiders in Lesser Kestrel diet in November-De- er Kcstrelincreases southward in the Free State.This prob- cember found in this study may partly be the result of ably reflects relative abundance of orthopterans in th•s below average rainfall during the study period, but my province, with a much higher densily in semiarid Karoo findings need thrther confirmation, as pellets were col- than in wetter C}mbopogon-Themedagrasslands near Win- lected during one non-breeding season and none were burg. Due to low rainfall, populalion growth of orthopter- examined li•om an 'average'year. Under dry conditions, ans in November-December 1997 was probably slower as those recorded in November-December 1997, mass than normal. Such dry weather could be, however,bene- alate termite flights that normally take place in mid-sum- ficial to sun spiders,as their greatestpopulation density•s met are delayed (pers. observ.). Hence these insects,that in arid areasof Namaqualand (Northern Cape, SouthAf- are typically an important component of Lesser Kestrel rica) and southern Namibia (Lawrence 1955, Warton &et (Anderson et al. 1999, Kok et al. 2000) constiluted 1981). High proportion of sun spidersin the LesserKes- JuNE 2002 SHORTCOMMUNICATIONS 151

•0I i! ' " ßSolifug•e ßOrthoptem []Coleopter• IDOther • •0 -•. '"iii: •$olifugae •2o100

0 '• 60

80 - 20o i'i•::?:i•i• 8 i..O•,opter.I WinburgReddersburg EdenburgTrompsburg 20 IE]Other_• Figure2. Foodof wintering Lesser Kestrels in different 400 ,i:411 localities in the Free State. Bars indicate percentage of NOV. DEC. JAN. FEB. occurrence of given prey groups a• Winburg (N = 25

100 pellets), Reddersburg (N = 100 pellets), Edenburg (N = c 74 pellets), and Trompsburg(N = 85 pellets). Iß Solifug;e• aging. Many birds at Bloemfontein were observed arriv- 40 []Coleoptera ] ing at the roosting site up to a few hours after sunset. 20 I nøthe' This foraging habit of wintering LesserKestrels has not 0 ''" been previously reported (Brown et al. 1982). NOV DEC JAN FEB REsUMEN.--Presentamos los delos sobre la dieta del cer- nicalo menor (Falco naumanni), basados en el anfilisis de Figure 1. Monthly changesin percent of main preygroups in LesserKestrel diet winteringin Bloemfontcinarea, South egagr6pilas.Las egagr6pilas(N = 2050) fueron colecta- des en sitiosde percha en el Free State, Sudfifrica,donde Africa. A•frequency of occurrence in 2050 pellets, B• los cern•calosforrajean in pastizalesy camposcultivados. number of prey (total number of prey items = 16915), and C•wet biomassof prey (total wet biomass= 21 570 g). La mayoHa de egagr6pilasfi•eron colectadasde una sola percha en Blocmfontein. Solifugae (Arafias sol) consti- tuycron el grueso de la dieta, pero Orthoptera (princi- trel's diet may also be partly attributed to their rapid, pahnente Acrididae) y Coleoptera (principalmente Sca- mouse-likemovements, which may attract the attention of rabaeidae) fueron tambiEn componentes importantes. LesserKestrels hunting from a high vantagepoint. Otros grupos de artr6podos tales como Isoptera, Der- Accordingto McCann (1994), LesserKestrels generally move up to 33 km from their roosting siteswhile forag- 80 ing. About 2000 birds were present each evening at the Bloemfontein roost during the australsummer 1997-98. 70 [ß Jan.--Feb. Assuming that each bird produces two pellets per day -• 60 •_Nov.--Dec. (Bijlsmaet al. 1988, McCann 1994), I estimatedthat dur- 50 ing the study period, the flock consumedca. 2 400 000 • 40 sun spidersin zu•area of ca. 1500 km•. This demonstrates how common sun spidersare in dry grasslands,and how important they can be in feeding LesserKestrels during 20 prolonged droughts. •0 Both in the breeding season (Cramp and Simmons o ...... 1980, Bijlsmaet al. 1988) and in the non-breedingseason (Anderson et al. 1999, Kok et el. 2000) Lesser Kestrels 12 3•u2b e r6of •o I•fu ;ae10p r:ly:; rPellet1314 15 16 17' prey extensivelyon arthropods, which are largely crepus- cular or nocturnal (e.g., sun spidcrs, crickets,earwigs, scolopendras,scarabacids, termite elate, and mole crick- Figure 3. Number of sun spidersper LesserKestrel pellet ets Gryllotalpaspp.; Scholtz and Hohn 1985, Bijlsmae• al. in dry months (November-December 1997; 50 mm of rain- 1988). Hence, it seemslikely that LesserKcstrels are to fall) comparedto wet months (January-February1998; 420 some extent crcpuscular,or even nocturnal, in their for- mm of rainfall) near Bloemfontein, South Africa. 152 SHO•T COMMUNICATIONS VOL. 36, NO. 2 maptera,Blattodea, Odonata y Scolopendromorphacom- DELHOYO, J., A. ELLIOTT,AND J. SARGATAL(EDS.). 1992. plementaron la dieta. Solamenteunos pocosroedotes Handbook of the birds of the world. Vol. 1. Lynx Edi- pequefiosfueron registrados.La proporci0nde losprin- cions, Barcelona, Spain. cipalesgrupos de presa fue similar a lo largo de Free GONZALEZ,J.L. AND M. MERINO.1990. E1 cernicalo pri- State, pero cambio marcadamenteen la estaci0ninver- milia (Falconaumanni) en la Peninsula Iberica. Situa- hal. Con la progresi0ndel verano austral,la proporci0n cion, problematica y aspectosbiologicos. Serie Tec- de SolifugaedecreciC, mientras que los otrosgrupos de nica. ICONA, Madrid, Spain. presa aumentaron.La gran proporci0n de presascre- KOK, O.B., A.C. KOK, AND C.A. VAN EE. 2000. Diet of mi- puscularesy nocturnasen la dieta del cernicalosugiere grant LesserKestrels Falco naumanni in their winter que este es al menos parcialmentecrepuscular en sus quartersin SouthAfrica. Acta Ornithol. 35:147-151. h/tbitos de forrajeo. LAWRENCE,R.F. 1955. Solifugae,scorpiones and pedipal- [TraducciCnde CCsarM/trquez] pi. S. Afr. Anim. Life 1:152-262. MCCANN, K.I. 1994. Habitat utilisation and time-energy ACKNOWLEDGMENTS budgets of the LesserKestrel Falco naumanniin its I gratefullyacknowledge comments, corrections, and southern African non-breeding range. M.S. thesis, suggestionsmade by Dr. AndrewJenkins, and Johan van Univ. of Witwatersrand,Johannesburg, South Africa. Nxekerk and Johan Kok for collectingpellets from roost- Roos, Z.N. ANt) M.M. Roos. 1986. First report: Lesser ing sitesoutside Bloemfontein. Kestrel survey.Miralta 3:46-48. LITERATURE CITED SCHOLTZ, C.H. AND E. HOLM. 1985. Insects of southern ANDERSON,P.C., O.B. KOK, AND B.H. ERASMUS.1999. Diet, Africa. Butterworths, Durban, South Africa. SIEGFRIED,W.R. AND D.M. S•:EAD.1971. Status of the Less- body mass,and conditionof LesserKestrels Falco nau- er Kestrel in South Africa. Ostrich 42:1-4. manni in South Africa. Ostrich 70:112-116. BIJLSMA,S., E.J.M. HAGEMEIJER,GJ. VERKLEY,AND R. ZO- TUCI•ER,R.M. ANt) M.F. HEATH. 1994. Birds in Europe their conservation status. BirdLife International, LLINGER.1988. Ecologicalaspects of the LesserKestrel Falconaumanni in Extremadura (Spain). Rapport 28, Cambridge,U.K. WerkgroepDieroecologie, Vakgroep Experimentde VAN ZYL,AJ. 1993. Foragingof the SouthAfrican Rock Kestrel. In Nicholls and Clarke [EDS.] Proc. 1991 Zoologic,Katholieke Univ. Nijmegen. Hawk and Owl Trust Conference, The Hawk and Owl BROWN, L.H., E.K. URBAN, AND K. NEWMAN. 1982. The birds of Africa. Vol. 1. Academic Press, London, U.K. Trust, London, U.K. COLM4AN,B.D. 1993. Status of the Lesser Kestrel in urban WHARTON,R.A. 1981. Namibian Solifugae (Arachnida). Cimbebasia Mem. 5:1-87. and peri-urbanareas in the ,South Africa. Mirafa 10:33-39. CP,AMP, S. AN• ILE.L. SIMMONS.1980. The birds of western Received13 May 2000; accepted26 December 2001 palearctic.Vol. 2. OxfordUniv. Press, Oxford, U.K. Associate Editor: Ian G. Warkentin

J RaptorRes. 36(2):152-153 ¸ 2002 The Raptor ResearchFoundation, Inc.

RED-SHOULDERED HAWK FEEDS ON CARRION

BILL P}tANTY • AvonPath Air ForceRange, 4 75 EasyStreet, Florida 33825 U.S.A.

KEYWORDS: Red-shoulderedHawk; Buteo lineatus;feeding; Range,Highlands County, Florida, I observedan adult Red-shouldered Hawk (Buteolineatus) drop off a fence post about 65 m awayand land on the grassyshoulder of At 0804 H on 1 June 1999 at Avon Park Air Force a paved road. The hawk picked up an object in its talons, flew back to a fence post, and began manipulating the item. Through Zeiss10 X 25 binoculars,I identified the i Present address: Audubon of Florida, 410 Ware Boule- prey as a Common Nighthawk (Chordeilesminor), with vard, Suite 702, Tampa, Florida 33619 U.S.A.; E-mail ad- conspicuouswhite barson the long, blackishwings. The dress:[email protected] nighthawkremains appeared to consistsolely of feathers