White-throated Sparrows Adopting New Songs

BY MICHAEL MCGUIRE

To casual observers and novice birders, sparrows often all look like the same small brown birds. However, there are about 10 to 15 different common species in our area. Some are year-round and some present only at certain times of year.

One interesting feature of sparrows is they have songs with a learned component, meaning not all members of the same species have exactly the same song. People generally learn standard songs of a species but there is subtle variation or dialect by region. Sometimes there is even variation among individuals in the same location.

Usually, differences are so subtle and stable most would not notice — or perhaps they would notice only after moving to a different part of the country. Occasionally, more drastic changes rapidly spread through populations, leaving birds of the same species with very different songs.

This song variation can be observed in one locally very common species; white-throated sparrows. These sparrows have both light and dark morphs with each variety occurring at roughly equal frequency. The two morphs look different, but each has a characteristic white throat and distinctive bright yellow lores on each side at the front of the crown between the bill and eyes. The light/white morph has a white and black striped crown while the dark/tan morph has a brown and tan striped crown.

Popular mnemonics for the original song include “Oh sweet Canada, Canada, Canada” and “Poor Sam Peabody, Peabody, Peabody.” However, white-throated sparrows are adopting a new song with two notes instead of three, making the old mnemonic something more like “Oh sweet Cana, Cana, Cana”. The new song started in British Columbia in western Canada sometime before 2000 and has since gone viral, rapidly spreading east, completely replacing the old song in many areas. It is now being heard in breeding white-throated sparrows as far east as Quebec. Scientists and birders can only speculate why, but we can all listen and appreciate the amazing change in progress.

White-throated sparrows are a very common local feeder bird in the winter and during spring and fall migration. Like most birds, generally only males sing and only during breeding season, with the purpose of attracting a mate and defending territory.

The best time to hear and compare the two songs is mid-April to early May. At this time, many birds from breeding areas farther north and west have started to sing the new two-note song as they migrate through while other migrating birds are singing the old three-note song. Every year, the two-note song becomes more and more frequent.

By the mid to late May, most remaining sparrows are those which breed very close and the old three-note song dominates. By June, they have all disappeared from the valley and can be found only in local mountains.

These breeding white-throated sparrows sing the old song, but someday soon this may change.

Look and listen for them in mountains with cool Boreal forest/wetland habitats, especially blueberry thickets. North Mountain in Ricketts Glen State Park is a reliable place to find breeding white-throated sparrows in June and July.