Year: 1994
Type: article
Abstract: ASSTRACt.--YelIowWarblers (Dendroica petechia) defend small territories in isolated patches of trees in cattle pastures in the Lacandon Forest of Chiapas, Mexico.We observed interspecific aggression much more frequently than intraspecific aggression.Although aggression by Yellow Warblers was directed at a minimum of 37 species, resident and migrant alike, attacks on Magnolia Warblers (Dendroica magnolia) comprised 35% of the total observed.We found that individual Magnolia Warblers use overlapping home ranges where one warbler tends to be the predominant occupant of a single Yellow Warbler territory.Overlap between neighbors was promoted by the aggressive chasing of Yellow Warblers.Arthropods were twice as abundant in the canopy as in understory shrubs.Exclosure experiments showed that birds harvested approximately 80% of the arthropods available in the canopy and 50% of those available in the understory vegetation.Yellow Warbler defense may be responsible for this difference in density in foliage arthropods between the canopy and understory.To avoid aggression, subordinate species depended on the presence of refugia, comprised of dense understory vegetation.Maintaining the structural heterogeneity of arroyo vegetation may provide critical habitat for many species of migratory birds in cattle pastures.Taken together, the interspecific aggression, intraspecific territoriality, and high rates of resource depletion indicate that competition plays an important role in determining the carrying capacity of second-growth remnants for migratory birds and their use of habitats.
Authors: Russell Greenberg, Javier Salgado Ortíz
Language: English
Topic: Avian ecology and behavior
Subfield: Ecology
Field: Environmental Science
Domain: Physical Sciences
SDG: Life on land
Open Access status: green
OpenAlex ID: W2518379374