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NORTH AMERICAN FAUNA 75 



we have no records of gray foxes from Parque Nacional Braulio Carrillo, we suspect 

 that they occur there. Apparently these foxes are found throughout the country 

 except for the Atlantic lowlands. The biology of gray foxes, based primarily on 

 studies in the eastern United States, recently was reviewed by Fritzell and Haroldson 

 (1982). 



Acknowledgments 



We are pleased to thank the Servicio de Parques Nacionales, especially 



F. Cortes and the many park guards, for making our studies in Parque Nacional 

 Braulio Carrillo possible, profitable, and enjoyable. E. Lopez Pizarro and 



G. Canessa Mora of the Departamento Vida Silvestre facilitated permits for 

 our work. The Organization for Tropical Studies, especially R. Butterfield, G. S. 

 Hartshorn, L. A. McDade, and C. E. Schnell went above and beyond the call 

 of duty to provide first-rate and indispensable logistic assistance. Funding for this 

 project was provided by the Field Museum of Natural History, National Geographic 

 Society, Organization for Tropical Studies, Rice Foundation of Chicago (we 

 especially thank Mr. and Mrs. A. A. Nolan, Jr.), and Universidad Nacional de 

 Costa Rica. We are extremely grateful to each of these organizations for making 

 our studies possible. We heartily thank R. Aguilar F. , J. S. Ashe, R. J. Izor, D. G. 

 Pranke, and J. H. Shook, Jr., for providing excellent technical and logistic 

 assistance in the field, often under trying conditions. R. L. Wenzel provided us 

 with the identifications of the bat flies we collected, and J. E. Keirans provided 

 us with the identifications of the ticks. S. Boinski, A. P. Brooke, G. Hartshorn, 

 D. H. Janzen, and L. McDade freely shared their unpublished observations on 

 mammals with us. J. Rodriguez (University of Costa Rica), S. B. George (Natural 

 History Museum of Los Angeles County), J. S. Findley and T. L. Yates (Univer- 

 sity of New Mexico), J. K. Jones, Jr. and R. D. Owen (Texas Tech University), 

 P. Myers (University of Michigan), B. D. Patterson (Field Museum of Natural 

 History), D. A. Schlitter (Carnegie Museum of Natural History), and B. Stein and 

 J. L. Patton (Museum of Vertebrate Zoology) were extremely helpful in making 

 specimens housed in their respective collections available to us for study. J. K. 

 Adams, A. L. Gardner, J. Hoth, R. W. McDiarmid, C. Thorington, M. D. Tuttle, 

 and N. Woodman provided us with some of the photographs that are published 

 here. We especially thank J. Wigles worth for her efforts in expeditiously and cheer- 

 fully typing the numerous drafts of this manuscript. M. A. Bogan, G. K. Creighton, 

 A. L. Gardner, G. S. Hartshorn, J. K. Jones, Jr., L. A. McDade, P. A. Opler, 

 D. E. Stone, and N. Woodman provided us with valuable suggestions on earlier 

 drafts. We appreciate the care and expertise A. M. Musser used in drafting the 

 map (Fig. 1). 



