This is an interesting question that many bird enthusiasts may wonder about. Sparrows are common backyard birds found throughout North America. There are many different species of sparrows, each with their own distinct size, coloration, and habits. Two of the most recognizable sparrow species are the fox sparrow and the song sparrow. But which one is larger? Let’s take a closer look and compare the sizes of these two types of sparrows.
Fox Sparrow Overview
The fox sparrow (Passerella iliaca) is a large, boldly marked sparrow species found in North America. They are chunky sparrows with a wingspan around 9.1-10.2 inches (23-26 cm), a length around 6.3-7.1 inches (16-18 cm), and a weight of 1.0-1.4 ounces (28-40 g). Their size helps distinguish them from other smaller sparrow species.
Fox sparrows are striking birds with reddish-brown upperparts, gray faces, and bold breast spotting. Their large size, in addition to their coloring, makes them easy to identify. There are four subspecies of fox sparrows, each with slight variations in appearance and breeding range:
- Slate-colored fox sparrow – Breeds in northwestern Canada
- Sooty fox sparrow – Breeds in Alaska
- Thick-billed fox sparrow – Breeds in central Canada
- Red fox sparrow – Breeds in northeastern Canada and western mountains
Although they vary slightly across subspecies, fox sparrows are generally one of the larger sparrow species. Their thick bills and large size help them eat seeds and insects and survive cold northern winters.
Song Sparrow Overview
The song sparrow (Melospiza melodia) is a very common sparrow species found throughout most of North America. They are a medium-sized sparrow with an average wingspan of 7.1-9.1 inches (18-23 cm), length of 4.7-6.3 inches (12-16 cm), and weight of 0.9-1.5 ounces (24-42 g). Although a common backyard bird, they are slightly smaller than fox sparrows.
Song sparrows are brown-streaked birds with a distinctive dark spot in the center of their streaked breast. Their most recognizable feature is their melodious song, which can consist of over 200 individual phrases. There are over 30 subspecies of song sparrows, showing incredible geographic variation in size and coloring across their range.
In general, song sparrows are medium-sized sparrows, smaller than fox sparrows but larger than tiny sparrow species like the chipping sparrow. Their smaller size allows them to survive on both seeds and small insects.
Fox Sparrow vs Song Sparrow Size
When directly compared, fox sparrows are clearly larger than song sparrows. Fox sparrows outweigh song sparrows by about 0.2-0.6 ounces (5-15 g) on average. They also have a wingspan about 1-2 inches (3-5 cm) longer than song sparrows. The table below summarizes the size differences:
Measurement | Fox Sparrow | Song Sparrow |
---|---|---|
Length | 6.3-7.1 in (16-18 cm) | 4.7-6.3 in (12-16 cm) |
Wingspan | 9.1-10.2 in (23-26 cm) | 7.1-9.1 in (18-23 cm) |
Weight | 1.0-1.4 oz (28-40 g) | 0.9-1.2 oz (24-34 g) |
The size differences between the two species results from the fox sparrows’ adaptation to surviving harsh northern winters. Their larger size requires more energy but also allows them to be more resilient in frigid weather and dig through snow for food.
Length
Fox sparrows are 16-18 cm long on average, while song sparrows are a bit smaller at 12-16 cm long. This 1-2 cm difference in length is small but noticeable when observing the two species side-by-side.
Wingspan
The wingspan difference is a bit more pronounced, with fox sparrows having a wingspan about 2-5 cm longer than song sparrows. Their broader wings help provide more power for migrating long distances each season.
Weight
Weight shows the clearest size difference between the two species. Fox sparrows outweigh song sparrows by 5-15 g, a result of their larger overall size and thicker, sturdier body shape. More weight provides insulation against cold and reserves to survive winter food shortages.
Behavioral Differences
In addition to size, fox sparrows and song sparrows differ in their behavior and habits.
Fox sparrows tend to forage on the ground, using their large size and strong legs to scratch and dig through leaf litter. They mainly eat seeds and insects. During migration and winter, they form loose flocks. Their winter range consists of southern Canada and the eastern and western United States.
Song sparrows are extremely territorial during breeding season. They forage for food on the ground and in low shrubs. Their diet consists of a mix of seeds and insects. Year-round they usually remain solitary or in pairs, not forming flocks like fox sparrows. They are non-migratory and reside year-round throughout most of North America.
Identification Tips
The following tips can help identify fox and song sparrows:
- Fox sparrows are large, chunky sparrows with bold spotting and streaking on their underparts. Look for reddish-brown upperparts.
- Song sparrows are a smaller, slimmer sparrow with fine streaking on their underparts and a dark breast spot.
- Check the bird’s proportions – fox sparrows have a large head, thick neck, and plump body.
- Fox sparrows have a large, triangular bill perfect for eating seeds. Song sparrows have a smaller, conical bill.
- Listen for vocalizations. Fox sparrows give a clear whistle and song sparrows aptly give melodious songs.
- Check habitat and range. Fox sparrows prefer wooded areas while song sparrows thrive in open scrubby habitat.
Conclusion
After looking at the measurements, proportions, and habits of these two common North American sparrows, it is clear that fox sparrows are indeed larger than song sparrows. Their chunky proportions, larger wingspan, greater weight, and bold streaking help distinguish them from the smaller and more finely marked song sparrows. Paying attention to subtle size and structural differences makes identifying sparrow species much easier. So next time you see a large, hefty sparrow scruffling through leaf litter, it’s likely a fox sparrow. But if you notice a smaller, energetic songster with fine streaks perched on a fence, that will be a song sparrow. Careful observation and an eye for detail go a long way in sparrow identification!