Journal of Caribbean Ornithology 20(1), 2007 53 THE ECOLOGY of the Jamaican Owl (Pseudoscops grammicus) and other endemic Caribbean owls is poorly known. Brief accounts of the Jamaican Owl?s diet have appeared in The Birds of Jamaica (Gosse 1847) and in the Gosse Bird Club Broadsheet (Downer 1973, Johnston 1976, Lewis 1976, Sutton and Sutton 1988). The Broadsheet reports have been overlooked in the secondary literature on owls (del Hoyo et al. 1999). Here I summarize the dietary data contained in past reports and document the presence of a passerine bird and rat in regurgitated pellets recently recovered near a Jamaican Owl roost in Kingston. Philip Henry Gosse (1847) examined the stomach contents of three female specimens. An adult?s stomach (p. 21) was ?stuffed with the hair and bones of a portion of rat, and the legs of a large spider: a Lycosa, as I believe?certainly a ground spider.? The stomach of an immature (p. 21) contained ?an immense quantity of slender bones, which appeared to be Anoles, as I discovered by the iguaniform teeth of at least five sets of jaws of various sizes there were also the remains of beetles, and of orthopterous insects.? A second immature (p. 22) contained the remains of mice and the elytra of small beetles. Gosse also mentioned second-hand reports that the owl entered pigeon coops to take squabs. With the exception of a sight record of an adult owl with a large frog at Marshall?s Pen, Manchester Parish (Sutton and Sutton 1988), the Broadsheet references present data from regurgitated pellets (Downer 1973, Johnston 1976, Lewis 1976). Disintegrated pellets recovered by Robert Sutton and Downer at an unnamed location contained fragments of pseudophylline katydids and the bones PREY REMAINS OF THE JAMAICAN OWL (PSEUDOSCOPS GRAMMICUS) GARY R. GRAVES Department of Vertebrate Zoology, MRC-116, National Museum of Natural History, Smithsonian Institution, P.O. Box 37012, Washington, D. C. 20013-7012; e-mail: gravesg@si.edu Abstract: Dietary information for the Jamaican Owl (Pseudoscops grammicus) is limited to several brief reports beginning with the account of Philip Henry Gosse in The Birds of Jamaica (1847). Regurgitated pellets recently recovered near a roost in Kingston contained the remains of Black Rat (Rattus rattus) and Greater Antillean Grackle (Quiscalus niger). This is the first conclusive evidence that the Jamaican Owl preys on passerine birds. Collectively, data from stomach contents and pellets suggest that the owl is a generalist predator of large invertebrates, frogs, lizards, introduced murid rodents, and passerine birds. Key words: Black Rat, Greater Antillean Grackle, Jamaica, Jamaican Owl, owl pellets, Pseudoscops grammicus, Quiscalus niger, Rattus rattus Resumen: RESTOS DE PRESAS DEL B?HO JAMAICANO (PSEUDOSCOPS GRAMMICUS). La informaci?n sobre la dieta del B?ho Jamaicano (Pseudoscops grammicus) est? limitada a varios registros breves que comienzan con el de Philip Henry Gosse en The Birds of Jamaica (1847). Los bolos regurgitados reci?n recobrados cerca de una percha en Kingston contienen restos de Rattus rattus y de Quiscalus niger. Esta es la primera evidencia conclusiva sobre el uso de aves paseriformes como presas en el B?ho Jamaicano. En conjunto, los datos de los contenidos estomacales y de los bolos sugieren que el b?ho es un depredador generalista de invertebrados de gran tama?o, ranas, lagartos, roedo- res muridos introducidos y aves paseriformes. Palabras clave: bolos de b?ho, B?ho Jamaicano, Jamaica, Pseudoscops grammicus, Quiscalus niger, rata, Rattus rattus R?sum? : LES PROIES DU HIBOU DE LA JAMA?QUE. Les informations sur le r?gime alimentaire du Hibou de la Ja- ma?que (Pseudoscops grammicus) se r?sument ? quelques brefs rapports d?butant avec l?apport de Philip Henry Gosse dans The Birds of Jamaica (1847). Les pelotes de r?jection trouv?es r?cemment pr?s d?un reposoir ? Kingston contenaient des restes de Rat noir (Rattus rattus) et le Quiscale noir (Quiscalus niger). C?est la premi?re confirmation que le Hibou de la Jama?que se nourrit de passereaux. Globalement, les donn?es des contenus stomacaux et des pelo- tes sugg?rent sue le Hibou de la Jama?que est un pr?dateur g?n?raliste de grands invert?br?s, de grenouilles, de l?- zards, de rongeurs introduits et de passereaux. Mots-cl?s : Hibou de la Jama?que, Jama?que, pelotes de r?jection, Pseudoscops grammicus, Quiscale noir, Quisca- lus niger, Rat noir, Rattus rattus J. Carib. Ornithol. 20:53-55, 2007 54 Journal of Caribbean Ornithology 20(1), 2007 could not be located on subsequent days. I periodically searched the grounds near the roost area for prey remains over the next several months and finally discovered two pellets on 3 April 2006 under a talipot palm only 15 m from the November roost site. I measured the external dimensions and dry mass of the pellets, dissected them, and identified prey remains through comparison with reference collections in the National Museum of Natural History. The size and shape of owl pellets vary among species but most are cylindrical when regurgitated (Andrews 1990). The Jamaican Owl pellets (~ 6.0 ? 5.5 ? 2.0 cm) were probably flat- tened by the impact with the ground below the roost. One pellet (Fig. 1A) contained a largely complete skeleton (minus the skull) of a Greater Antillean Grackle (Quiscalus niger) and three isolated rat bones (vertebra, ilium, and ulna) embedded in a loose matrix of black feather barbs and feather fragments (bone = 2.51 g; feather = 1.39 g; measured with digital scale). Skeletal elements of Quiscalus niger can be easily distinguished from those of the Jamaican Blackbird (Agelaius niger- of Anolis lineatopus (Downer 1973). Johnston (1976) reported the contents of two pellets from Glenrock, St. Thomas Parish, and three pellets from Camberwell, St. Mary Parish. The Glenrock pellets included the remains of Black Rat (Rattus rattus), House Mouse (Mus musculus), bat (unidentified species), giant galliwasp (Celestus occiduus), gecko (Hemidactylus sp.), frogs (Hyla septentrionalis and Eleutherodactylus sp.), katydids, cricket, mollusk (Subulina octona), and grass fragments. Lewis (1976) suggested that the galliwasp was more likely referable to the common Celestus hewardii rather than the presumably extinct C. occiduus. The Camberwell pellets contained a bone fragment, unidentified hair, cricket (Urogryllus sp.), flea, beetle elytra fragment, unidentified insect parts, grass and plant stem fragments, light brown feathers, fine grit, and a piece of string. On 27 November 2005, I photographed an adult Jamaican Owl roosting in a broad-leafed tree partially shaded by a large talipot palm (Corypha umbraculifera) in Hope Botanical Gardens (18? 01.30? N, 76? 44.89? W; WGS-84). The owl re- mained stationary from 09:30 hr until 17:00 hr but Fig. 1. Jamaican Owl (Pseudoscops grammicus) pellets. Skeletal elements of a Greater Antillean Grackle (Quiscalus niger) protrude from pellet A. GRAVES ? PREY REMAINS OF PSEUDOSCOPS GRAMMICUS IN JAMAICA Journal of Caribbean Ornithology 20(1), 2007 55 rimus), Shiny Cowbird (Molothrus bonariensis), and the introduced Eurasian Starling (Sturnus vulgaris), by their larger size. The humerus of the grackle also exhibits a deep tricipital fossa which is absent in the starling and Smooth-billed Ani (Crotophaga ani). The presence of the pygostyle, claws, phalanges, both carpometacarpi, and frag- ments of ribs, sternum and synsacrum in the pellet, suggests that the owl swallowed the entire body of the grackle after it was decapitated. Mean body masses of Greater Antillean Grackles in Jamaica range from 76 g (females) to 108 g (males; S. E. Koenig pers. comm.). This is the first conclusive evidence that the Jamaican Owl preys on passerine birds. The second pellet (Fig. 1B) contained the nearly complete skeleton, including skull and mandibles, of a juvenile Black Rat embedded in a compact mass of hair (bone = 2.84 g; hair = 3.55 g). The ulna (length = 21.73 mm) contained in pellet 1A was very similar in size to the lone ulna (length = 21.79 mm) present in pellet 1B. This suggests a single rat was represented in the two pellets. In summary, regurgitated pellets and stomach contents indicate that the Jamaican Owl is a generalist predator of large invertebrates, frogs, lizards, introduced murid rodents, and passerine birds. These data also suggest that the owl may exert strong selection on nocturnal roost sites in passerine birds and lizards. ACKNOWLEDGMENTS I thank Catherine Levy and Susan Koenig for comments on the manuscript and for providing references. Field research was funded by the James Bond and Alexander Wetmore funds of the Smithsonian Institution. Research and export permits were issued by the National Environmental Planning Agency, Kingston (Yvette Strong and Andrea Donaldson). Helen James confirmed the identification of the avian skeletal elements. LITERATURE CITED ANDREWS, P. 1990. Owls, caves, and fossils: predation, preservation, and accumulation of small mammal bones in caves, with an analysis of the Pleistocene cave faunas from Westbury-sub- Mendip, Somerset, UK. University of Chicago Press, Chicago, IL. DEL HOYO, J., A. ELLIOTT, AND J. SARGATAL. 1999. Handbook of the birds of the World. Vol. 5. Barn-Owls to Hummingbirds. Lynx Edicions, Barcelona. DOWNER, A. 1973. Brown Owl pellet. Gosse Bird Club Broadsheet 21:15-16. GOSSE, P. H. 1847. The birds of Jamaica. Bentley, Wilson and Fley, London. JOHNSTON, D. 1976. More Jamaican Owl pellet contents. Gosse Bird Club Broadsheet 26:13. LEWIS, B. 1976. Jamaican Owl pellet contents. Gosse Bird Club Broadsheet 26:16. SUTTON, R., AND A. SUTTON. 1988. Jamaican Owl feeds juvenile on frog. Gosse Bird Club Broadsheet 50:15-16. GRAVES ? PREY REMAINS OF PSEUDOSCOPS GRAMMICUS IN JAMAICA