American Tree Sparrow

Spizelloides arborea

The American tree sparrow, also known as the winter sparrow, is a medium-sized New World sparrow. It breeds in Alaska and Northern Canada and winters in Southern Canada and the Contiguous United States. It is the only member of the genus Spizelloides. Source

Where it is now

In the last 8 weeks this bird was recorded 128,727 times across 50 areas (each area is a 5 degree square).

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Movement and weather

Each season it is first heard regularly where daytime highs are around 16°C (typically 6 to 22°C, from 19 areas). That range is wide, so temperature alone does not explain when it turns up.

Arrival dates

The week it was first heard regularly in each region, after at least six weeks away. Dates differ from south to north, so a region has a range.

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Figures are effort corrected and come from automatic sound identification, which makes mistakes. How this is measured and how it compares with human observers.