10.1371/journal.pone.0025272.g009 Eiji Matsunaga Eiji Matsunaga Kenta Suzuki Kenta Suzuki Shigeki Kato Shigeki Kato Tohru Kurotani Tohru Kurotani Kazuto Kobayashi Kazuto Kobayashi Kazuo Okanoya Kazuo Okanoya Examples of songs of birds GFP-virus injected at adult stage. Public Library of Science 2011 songs birds gfp-virus injected 2011-09-20 01:18:16 Figure https://plos.figshare.com/articles/figure/_Examples_of_songs_of_birds_GFP_virus_injected_at_adult_stage_/404696 <p>Sample sonograms of the song sequences of pre- and post-GFP virus-injected birds and scatterplots of 3,000 song notes (duration versus Wiener entropy).</p>