<I>Neophron Percnopterus</I>

j Raptor Res. 27(2):123 ¸ 1993 The Raptor ResearchFoundation, Inc.

LETTERS

PREDATION UPON NESTLING EGYPTIAN VULTURES (Neophronpercnopterus) IN THE VRATSAMOUNTAINS OF BULGARIA

J.A. DonAzar and O. Ceballos(1988, Ardeola35:3-13) indicatedthat, exceptfor their observations,very little has beenpublished about predation upon nestlings of the EgyptianVulture (Neophronpercnopterus; L. Brownand D Amadon1968, Eagles,hawks, and falconsof the world,Country Life Books,London, U.K., P.J. Mundy 1982, The comparativebiology of southernAfrican vultures, Vulture Study Group, Johannesburg, South Africa). We reporthere ten observationsof predationby mammalsand birdsupon nestling Egyptian Vultures occurring from 1987-1992. We observedtwo casesof predationby GoldenEagle (Aquila chrysaetos). On 2 June 1987 we saw an eaglecapture, kill, and eat a nestlingas it sunbathednear its nest.In a similarincident on 24 August1991, we saw an eaglecatch and carry away a nestlingsunbathing on a rock near its nest. On 29 June 1989, a nestlingvulture disappeared from its nest.We foundthe remainsof what was probablythe samenestling about 900 m away amongthe prey remainsof a pair of Eagle Owls (Bubobubo). Jackals(Canis aureus) apparently killed two nestlingsthat had fallenfrom their nestsand couldnot fly well. One wason 15 August1988 and the otheron 15 August1990. Another nestling fell froma neston 13 June 1990 andwas killed and eatenby a red fox (Vulpesvulpes). A groupof EgyptianVultures were observed feeding on a carcasson 20 August1989. Among them was an 86 d oldfledgling. When thegroup was approached by twowolves (Canis lupus), the adult vultures escaped, but thefledgling could not and was killed and eaten by the wolves. In additionto the incidentsnoted above, we know of three more nestlingskilled by red foxes.Thus, of 61 nestling vulturesthat hatchedin the intervalof our observations,10 (16.4%) were killed by predators(two by GoldenEagles, two by EagleOwls, two by jackals,four by red foxes,and oneby wolves).In addition,we observed12 unsuccessful predationattempts by GoldenEagles and six by CommonRavens (Corvus corax). Most of thevultures we documented diedbetween 65-70 d of age.After fledging,the vultures rarely returned to their nestsand were vulnerable to mammalian predatorswhile roostingin exposedsites where the adultscarried food to them. We are verythankful to L. Andreevfor helpin field work, P. Jankovfor helpfulcriticism on an earlierdraft, R. Stoyanovfor the loan of infrared binoculars,and J.A. Donfizar for drawing our attentionto his paper "Red Fox Predationon Fledgling Egyptian Vultures" that stimulated our paper.--Y. Stoyanova and N. Stefanov,Blvd. "Nikola Viovodov" 19, Apartment 79, Vratsa 3000, Bulgaria.

j Raptor Res. 27(2):123-125 ¸ 1993 The Raptor ResearchFoundation, Inc.

NORTHWARD MIGRATION OF PEREGRINE FALGONS ALONG THE CARIBBEAN COAST OF COSTA RIGA

Severalmigrant raptor species form immenseconcentrations during their annualnorthward and southwardmove- mentsthrough the Central Americanisthmus (N.G. Smith 1980, Hawk and vulture migrationsin the Neotropics, Pages51-65 in A. Keastand E.S. Morton [EDS.],Migrant birdsin the Neotropics:ecology, behavior, distribution, andconservation, Smithsonian Institution Press, Washington, DC U.S.A;A. Wetmore1981, The birdsof the Republic of Panama,Part 1, SmithsonianInstitution Press, Washington, DC U.S.A). The PeregrineFalcon (Falco peregrinus) occursin CentralAmerica principally as a migrant(P. Slud1964, The birdsof CostaRica, distribution and ecology, Volume128, Bull. Am. Mus. Nat. Hist., New York, NY U.S.A.; F.G Stilesand A. Skutch1989, A guideto the birds of CostaRica, CornellUniv. Press,Ithaca, NY U.S.A.). However,there are no reportsof thisspecies passing anywhere in CentralAmerica in largenumbers. We presenthere observations of a concentratedspring flight of peregrinesalong Costa Rica's Caribbean coast. Observationswere made during 1-3 May 1992between the portcity of Moln andthe Tortuguero area of Lim6n Province(Fig. 1). A fixedpoint of observationwas established at the CarloPalma Biological Research Station of the CanadianOrganization for TropicalEducation and Rainforest Conservation. The areaconsists of tropicalwet forest

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