Laura Erickson's For the Birds

(Recording of a White-crowned Sparrow)

Well, my self-proclaimed National Sparrow Week is going strong. Today’s featured sparrow is another one of my favorites, the White-crowned Sparrow. These birds are very common in the west, wintering throughout the southwest and breeding in large parts of Nevada, Utah, Oregon, and Washington. The eastern races winter in a band from Texas and Kansas across to Virginia and Pennsylvania. But they merely pass through Minnesota and Wisconsin, on their way to the Hudson Bay area. Their ephemeral visit here is all the more precious for its briefness. The White-crown is proof that May is the loveliest month of the year, even in a cold fog.

Of the 53 species of native American sparrows on the official checklist of the American Ornithologists’ Union, one of the most studied is the White-crown. Ornithologists around San Jose California have been studying them for years, and the body of information about these birds is immense. For example, in October, 1962, ornithologists captured and banded 574 of them and shipped them across the country to the Patuxent Wildlife Research Center in Maryland. The following autumn they recaptured 8 of them back in San Jose.

Many dialects of their song have also been identified, again in California where several different races winter together. When very young nestlings are isolated from their parents they develop a song different from the local dialect. Even though they don’t begin singing until they are a year old, if they are allowed to remain with their parents just until fledging, when they are about 10 days old, they will sing a perfect song, even if kept in a sound-proof chamber for the rest of the year.

Scientists have also studied the breeding cycles of races that winter together in San Jose. The sedentary race that also breeds in the same area exhibits a completely different breeding cycle from a race that winters with it in San Jose but migrates to the Puget Sound area for breeding. Differences include the timing of molt, the timing of sexual maturation, and when and how much body fat is put on. Obviously the changes in day length and temperature at the end of winter affect the two races completely differently.

Studies about orientation and navigation have also been conducted on White-crowns. As day length increases, they show nighttime restlessness, and 94% of the time choose perches on the north end of the cage at nighttime.

White-crowns have also been subjected to wind tunnel experiments to see how fast they can fly. In order to hold its position relative to the ground in high wind, they have been clocked at 39 miles per hour, and have actually managed to fly backwards against the wind in order to hold their position in a tail wind.

Ornithologists study White-crowns because they are easy to maintain in captivity, preferring a seed diet, they’re relatively abundant, and they’re easy to catch. I watch White-crowns because they are beautiful and because their brief passage through my world each spring and fall somehow brings my spirit closer to the wild Hudsonian world they call home.

(Recording of a White-crowned Sparrow)

This is Laura Erickson, and this program has been “For the Birds.”