Peter Marler, a UC Davis-based ornithologist who discovered that regional populations of songbirds can sing in distinct dialects, has died at age 86 of pneumonia, his family reports.
Marler, who retired from UC Davis in 1994, died July 5 while evacuated from his home in Winters, California due to the nearby Monticello Fire.
An expert in vocal communication among mammals and birds who worked with such luminaries as Jane Goodall and Hugo Von Lawick, Marler is credited with the discovery of regional dialects among white-crowned sparrows while teaching at UC Berkeley in the early 1960s.
White-crowned sparrows maintain relatively consistent territories from year to year at each end of their migrations. In other words, a white-crowned population that migrates from Southern California to Alaska will head for roughly the same location at either end of their journey. Since white-crowneds, like most other birds, learn to sing by listening to neighbors of the same species -- which Marler discovered while at Cambridge in the 1950s -- this fidelity to a relatively small territory allows regional differences in songs to develop over the generations.
This embedded video shows a number of sparrows in Portland in the act of singing. It's usually the males who sing, though females can be heard doing so on occasion when provoked.
You can hear examples of two different regional white-crowned sparrow dialects on the Cornell Lab or Ornithology's website, with one from Alaska and another from Oregon. But you don't need to choose populations as widely separated as that to tell one neighborhood's song from another. According to Marler's obit in the Sacramento Bee, he told that paper in 1997 that "Dialects are so well marked that if you really know your white-crowned sparrows, you'll know where you are in California."
Marler's 1962 paper heralding his discovery of the dialects looked at populations of the small songbirds in downtown Berkeley, at Inspiration Point in the Berkeley Hills a few miles from downtown, and on Sunset Beach in Santa Cruz County. The results: all three populations had distinct song dialects, though the Inspiration Point and Berkeley dialects, their locales separated from each other by just two miles, substantially resembled each other more closely than they did the dialect from Sunset Beach.
That suggested that local dialects may evolve through cultural influences, and later work by ornithologists such as the late Luis Baptista confirmed it: white-crowned sparrow dialects change over time, with some dialects going extinct as birds gradually adopt other dialects. (Baptista's June 2000 New York Times obituary covers some of the utterly fascinating work he built on Marler's discovery, including sparrows who "speak" two or three dialects, and some who use wholly different tonal scales from others.)
It's a fascinating glimpse into the minds of some of our most inconspicuous neighbors, and ReWild notes Marler's passing with sadness and profound gratitude. He leaves the world better informed than he found it.