Abstract
This paper is based on bird censuses conducted regularly along a 1000 m trail in a disturbed natural forest east of the city of Medellín, Colombia, over a period of 13 months. Forty species belonging to 19 families were found at the study site and 23 additional species in the surrounding area. The most abundant species were the Blue-and-black Tanager, Common Bush-Tanager, Sparkling Violetear and Tyrian Metaltail. Interspecies flocks occurred frequently in the area, usually with the Blue-and-black Tanager as nucleus species. The only regular migrant species was the Blackburnian Warbler, which constituted 6.2 % of all individuals censused during its presence from September to March.
References
Buskirk, W. H., V. N. Powell, J. F. Wittenberger, R. E. Buskirk & T. V. Powell. 1972. Interspecific bird flocks in tropical highland Panama. Auk 89: 612–624.
Chipley, R. M. 1976. The impact of wintering migrant wood warblers on resident insectivorous passerines in a subtropical oak wood. Living Bird 15: 119–141.
Espinal, L. S. 1964. Formaciones vegetales del departamento de Antioquia. Revista Facultad Nacional de Agronomía 24, Medellín.
Hilty, S. L. 1980. Relative abundance of north temperate zone breeding migrants in western Colombia and their impact at fruiting trees. Pp. 265–271 in Migrant Birds in the Neotropics (A. Keast & E. S. Morton, eds.). Smithsonian Institution Press, Washington, D.C.
Johnson, T. B. 1980. Resident and North American migrant bird interactions in the Santa Marta highlands, northern Colombia. Pp. 239–247 in Migrant Birds in the Neotropics (A. Keast & E. S. Morton, eds.). Smithsonian Institution Press, Washington, D.C.
Karr, J. R. 1976. On the relative abundance of migrants from the North Temperate Zone in tropical habitats. Wilson Bulletin 88: 433–458.
Leck, C. 1972. The impact of some North American migrants at fruiting trees in Panama. Auk 89: 842–850.
Meyer de Schauensee, R. 1948–1952. The birds of the Republic of Colombia. Caldasia 5: 251–1214.
— 1966. The species of birds of South America and their distribution. Livingston Publishing Co., Philadelphia.
— & W. H. Phelps, Jr. 1978. A guide to the birds of Venezuela. Princeton University Press, Princeton, N.J.
Miller, A. H. 1963. Seasonal activity and ecology of the avifauna of an American equatorial cloud forest. University of California Publications in Zoology 66: 1–78.
Moynihan, M. 1962. The organization and probable evolution of some mixed species flocks of neotropical birds. Smithsonian Miscellaneous Collections 143, No. 7.
Munves, J. 1975. Birds of a highland clearing in Cundinamarca, Colombia. Auk 92: 307–321.
Ridgely, R. S. & S. J. C. Gaulin. 1980. The birds of Finca Merenberg, Huila Department, Colombia. Condor 82: 379–391.
Short, L. L., Jr. 1961. Interspecies flocking of birds of montane forest in Oaxaca, México. Wilson Bulletin 73: 341–347

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.