4. Alien Dialects

Some animals we know through sight: glimpses through zoo cages or fish tanks. Some we know by touch: cats we pet, dogs whose tongues press against our faces. Many we know by taste. But birds we know mostly by sound, a constant background noise signifying their invisible presence in the space above us. Birdsong is the pastoral antidote to the sounds of the city, the urban spaces which overran our lives with modernity. Maybe now it’s the soothing reminder of a world outside our digitally-mediated lives. Or a sign of natural climate change when it marks the coming of spring? It’s something, at least, in the air above which speaks a language not of human origins. 

“Male white-crowned sparrows have song "dialects," acquired in about the first 100 days of life by learning from older males. In the laboratory an alien white-crowned sparrow dialect can he taught.” 

A young male white-crowned sparrow lives in a room. He might not know it, but he is one of 88. Through a loudspeaker, a song plays. For one, it’s his native song, the song of his father, his uncles, and, somewhere, maybe, his brothers. A song which marks the space to which he was born. For another, it’s a foreign song, the song of strangers, the song of miles-away and over-there. An alien dialect, the researchers call it. This is the essential premise of a study of song learning in white-crowned sparrows conducted by Peter Mahler and Miwako Tamura at UC Berkeley, published in 1964, which demonstrated that sparrows could learn a dialect of bird song different from their native one if exposed at a certain age. 

Besides showing that song patterns were culturally learned, the study also used sound spectrograms to analyze and represent the song patterns, an idea which Mahler says faced resistance. These spectrograms reveal a pattern of syllables in each bird song which differs regionally—long whistles to start, shorter high/low pitch alterations, drawn out warbling. It’s hard to translate these visual songs back into anything resembling auditory song, but this does show the differences in regions: those Sunset Beach birds seem more stressed than the Marin birds, while the Berkeley birds are obviously stoner intellectuals, you can just tell. But what do these differences mean? What does the sparrow do with the information that another sparrow is from slightly-further-north California? Or is this just form with no content, the content being that the song and its singer is simply in a particular area at all—pure medium, no message? Can there be a cultural transmission of learning without a culture? 

Do the sparrows return to the wild with their foreign dialects? Do they upend the existing sparrow linguistic culture? Mahler and Tamura briefly cite a study by Masakazu Konishi on song learning in deafened juncos, a paper which opens with a detailed description of the process of deafening: sedate the junco, pluck its feathers from its head, cut it open, and delicately remove its cochlea. Between the two pages of description and the detailed diagrams, I can safely say I learned enough to confidently deafen a junco if I ever meet one in the wild and need to assure it is not eavesdropping on my conversations. I appreciate the hard work of bird researchers of the Cold War era assuring that local birds will not be able to hear and learn our secret songs.