image: This is a reed warbler nest parasitized by common cuckoo; the larger egg is the parasitic egg. This image relates to an article that appeared in the June 5, 2009, issue of Science, published by AAAS. The study, by Dr. Nicholas B. Davies at the University of Cambridge in Cambridge, UK, and colleagues, was titled, "Social Transmission of a Host Defense Against Cuckoo Parasitism." view more
Credit: Image © <i>Science</i>/AAAS