April 2024
Bird of the Month
Song Sparrow
by Carolyn Preston
The Song Sparrow is a rich, russet- and-gray bird with bold streaks down its white chest and is one of the most familiar North American sparrows. There has been a total of 52 subspecies named under the Song Sparrow, but genetic divergence is low. This may be due to high rates of immigration and emigration keeping the populations genetically similar, while local conditions maintain the physical differences. Depending on location, the Song Sparrow can be pale or dark and heavily streaked, and can vary greatly in size.
Because of its abundance, the Song Sparrow is heavily studied. One study linked the size of the beak to the climate. The bill of a bird is highly important as a perfect place to radiate excess heat. Larger beaked subspecies were strongly correlated with hotter microclimates.
Like many other songbirds, the male Song Sparrow uses its song to attract mates as well as defend its territory. Studies have shown that the female Song Sparrow is attracted not just to the song itself, but to how well it reflects the ability of the male to learn. Males that had more complex songs were preferred. One study found that male song sparrows memorize a 30-minute-long playlist of their songs and deliberately shuffle and repeat their songs possibly to keep a female’s attention.
Courting birds fly together, fluttering their wings, with tails cocked up and legs dangling. Song Sparrows are primarily monogamous. The pair search for nest sites together and will reuse nests sites over and over. The sites are usually hidden in grasses or weeds, often near water. The female builds the nest, working mainly during the morning. The finished nest if 4-8 inches across and 2.5 – 4 inches deep. They lay 1-6 eggs 1-7 times a year. Incubation is 12-15 days with a nestling period of 9-12 days. At hatching the chicks are naked with sparse blackish down, with closed eyes and clumsy movement.
Song Sparrows eat many insects and other invertebrates in the summer, as well as seeds and fruits all year round. Food types vary depending on what is common across their range. Song Sparrows are widespread and common so are of low conservation concern. Common predators include, cats, hawks, owls, snakes and the American kestrel. Cowbirds may lay eggs in the Song Sparrow nests but the Song Sparrows will raise the Cowbird chick. The oldest known Song Sparrow was at least 11 years, 4 months old when it was recaptured and rereleased during banding operations in Colorado.
Chicks in Nest
Hatchlings
Female
Male