Figure 10. Summary of gene induction in vocal and movement-activated areas of vocal learners.

Intensity of green indicates relative levels of activity-induced dusp1 or egr1 induction in each area, determined from the in situ hybridizations (see methods). White (0), no detectable induction; Dark Green (1), highest induction levels. Gene induction in song nuclei is due to singing, and in regions adjacent to song nuclei is due to moving. * The values for hummingbirds are an average of several species: sombre hummingbird (n  = 3 singing, n  = 3 silent), Anna’s hummingbird (n  = 2 singing, n  = 1 silent), and rufous-breasted hermit (n  = 2 singing, n  = 1 silent). For anatomical abbreviations, see Table 1.