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Providing evidence to improve practice

Individual study: Impact of a long-term shiny cowbird Molothrus bonariensis control programme on nesting success of yellow warblers Dendroica petechia in Boqueron State Forest, south-western Puerto Rico

Published source details

Vincenty M., Tossas A.G., Bird-Pico F.J., Lopez-Ortiz R. & Ventosa-Febles E.A (2009) Yellow warbler (Dendroica petechia) breeding success in relation to shiny cowbird (Molothrus bonariensis) brood parasitism in Boqueron, Puerto Rico. Ornitologi­a Neotropical, 20, 523-533


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Remove/control adult brood parasites Bird Conservation

A before-and-after study in Puerto Rico (Vincenty et al. 2009) using some of the data from (López-Ortiz et al. 2006) found that the proportion of yellow warbler Dendroica petechia nests parasitized by shiny cowbirds Molothrus bonariensis fell following cowbird control (see López-Ortiz 2006). Nesting productivity of warblers also increased following cowbird control (0.7 warbler chicks/nest in 62 nests in 2001-2 vs. 0.35 warbler chicks/nest in 1977-80). However, the proportion of nests fledging chicks appeared to be lower following control (31% of nests in 2001-2 vs. 45% of nests in 1977-80). The majority of nests lost were predated (80% of 41 failed nests).