Study

Cowbird removals unexpectedly increase productivity of a brood parasite and the songbird host

  • Published source details Kosciuch K.L. & Sandercock B.K. (2008) Cowbird removals unexpectedly increase productivity of a brood parasite and the songbird host. Ecological Applications, 18, 537-548.

Actions

This study is summarised as evidence for the following.

Action Category

Remove/control adult brood parasites

Action Link
Bird Conservation
  1. Remove/control adult brood parasites

    A controlled before-and-after cross-over study between 2003 and 2005 at five tall-grass prairie sites (24-83 ha) in Kansas, USA (9) found that brood parasitism by brown-headed cowbirds Molothrus ater on Bell’s vireos Vireo bellii was significantly lower at sites where a total of 980 cowbirds (171 adult females, 724 adult males and 85 juveniles) were removed in 2004-5, compared to before removals (47 and 58% parasitism in 130 nests in removal plots in 2004 and 2005 respectively  vs. 64-81% parasitism in 130 nests in 2003). There was no corresponding decrease in areas when cowbirds were not removed (77-85% parasitism in 278 nests in non-removal plots in 2004-5). Vireo productivity was higher at removal plots (2.6 compared to 1.2 vireo fledglings/pair) and nest success was higher for non-parasitised nests (64% of nests producing at least one chick vs. 51% of parasitised nests). However, cowbird productivity was also higher for removal plots than control plots (0.3 compared to 0.1 cowbird chicks/vireo pair).

     

Output references
What Works 2021 cover

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 21

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.


Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape ProgrammeRed List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Mauritian Wildlife Supporting Conservation Leaders
Sustainability Dashboard National Biodiversity Network Frog Life The international journey of Conservation - Oryx Cool Farm Alliance UNEP AWFA Bat Conservation InternationalPeople trust for endangered species Vincet Wildlife Trust