Estrategias Anti Parasitos En La Mariquita De Puerto Rico (agelaius Xanthomus) Y El Canario De Mangle ( Dendroica Petechia): Dentro Y Fuera Del Area De Manejo Del Tordo Lustroso (molothrus Bonariensis

Resumen del Libro

The Shiny Cowbird (Molothrus bonariensis) is an obligate brood parasite. Brood parasitism can significantly reduce the reproductive success of some host species. Strategies to avoid parasitism include nest desertion, rejection, and burial of parasite egg. In Puerto Rico, the cowbird has coexisted with their principal hosts for about 60 years. Among the common hosts in Puerto Rico are the Yellow Warbler (Dendroica petechia) and the Yellow-shouldered Blackbird (Agelaius xanthomus). A previous study that took into consideration data from 1973 to 1982, did not detect the use of anti-parasitic strategies in the Yellow Warbler, but detect some evidence of possible strategies in the Yellow-shouldered Blackbird. Two decades later, I evaluated 544 broods of both hosts, including 90 broods that were experimentally parasitized and 84 broods that were naturally parasitized by cowbird. I compared the presence of the different possible anti-parasitic strategies with the published study. I found an increase in the use of anti-parasitic strategies (egg burial) in the Yellow Warbler, but in the Yellow-shouldered Blackbird I found no changes.