Song Sparrows are found in every state of the union and the Canadian provinces. They are the most common and widespread sparrow native to North America. There are 31 recognized subspecies of the Song Sparrow, more than any other bird species found in North America. Song Sparrows in different parts of the country can look amazingly different. Some are lightly marked and pale while others are dark and heavily streaked. Song Sparrows on the Aleutian Islands of Alaska are one-third longer and weigh twice as much as the ones in the eastern U.S. In the northern part of their range, Song Sparrows are partially or completely migratory depending on snow cover and winter temperatures. This is due to their ground feeding habits and their almost total dependence on weed seeds for food in the winter. When migrating, female Song Sparrows travel farther south than do their male counterparts.Adult male Song Sparrows perform from six to 200 different melodies. Some Song Sparrow songs may be very short, consisting of only four notes and lasting less than two seconds, while others may consist of 20 or more notes, lasting over five seconds. Studies have shown that female Song Sparrows are attracted to males that learn and sing a larger repertoire of songs. These males are much more successful in holding their territories and reproducing. During the dawn twilight on a spring morning, male Song Sparrows will sing a song every eight seconds and may average over 2,300 songs during an entire day.The nest of the Song Sparrow is usually found under grassy tufts on the ground or low in a bush or shrubbery. The female Song Sparrow does most of the nest construction, while the male defends his territory. A pair of Song Sparrows may raise up to four broods a year.A Song Sparrow's natural diet consists of weed and grass seeds, a few berries, and insects. They prefer to forage on the ground and readily visit backyard feeders where seeds, especially millet, are offered. Song Sparrows forage for food on the ground by using a double-scratch technique called the "Song Sparrow Samba." They kick away debris by hopping forward while sweeping both feet quickly back along the ground. Song Sparrows select their seeds based on what is the most abundant and easiest (fastest) to open - such as millet. Harder to open seeds, even those with a higher fat and protein content - such as oil sunflower - are much less likely to be eaten. On average, Song Sparrows digest and absorb between 80-90% of the food they eat. Their highly efficient digestive system takes about two hours to process the food from start to finish. The average weight of a Song Sparrow is around 24 grams (.85 ounces), but studies have shown that their weight can fluctuate up to 20% in 24 hours.Song Sparrows are very aggressive around feeders and can even dominate larger sparrows and other birds. They rarely feed in flocks and usually search for their food alone or in the company of one or two other birds. This behavior makes them vulnerable to hawks and other predators, thus the presence of nearby shrubbery and cover is very important to them.---------------------------Local bird expert Larry Collins owns Wild Birds Unlimited, 2454 Hwy. 6&50, which caters to folks who want the best backyard birdfeeding experience possible. Email your birdfeeding and birding questions to firstname.lastname@example.org and he'll answer them in his bi-weekly Q&A column in the Free Press.