FIGURE 10-23 Birdsong Dialects The songs of male white-crowned sparrows recorded in three locales around San Francisco Bay are similar, but sound wave spectrograms reveal that the dialects differ. Like humans, birds acquire regional dialects.

Information from P. Marler (1991). The instinct to learn. In S. Carey & R. German (Eds.), The epigenesis of mind: Essays on biology and cognition (p. 39), Hillsdale, NJ: Erlbaum.