- 4.7–5.9 in
- 7.9 in
- 0.4–0.5 oz
- Smaller and more slender than a Song Sparrow; larger than a Black-capped or Carolina Chickadee.
- Bruant des champs (French)
- Chimbito Llanero (Spanish)
- If a male Field Sparrow survives the winter, it usually returns to breed in the same territory each year. The female is less likely to return to the same territory, and young sparrows only rarely return the next year to where they were born.
- The male Field Sparrow starts singing as soon as he gets back in the spring. He sings vigorously until he finds a mate, but after that he sings only occasionally.
- Female Field Sparrows arriving on the breeding grounds may experience a rude welcome from males seeking a mate. An unmated male will often fly at and strike a female on his territory, sometimes driving her to the ground. Such an approach seems to seal the deal; by the following day the male is following his mate closely as she searches for a nest site.
- Field Sparrows often breed more than once a season. They build a new nest each time, building them higher and higher off the ground as the season progresses. Early spring nests are often on the ground, where they’re less visible. As leaves and groundcover grow the birds build their nests in bushes and trees, where they’re safer from snakes and other predators.
- Field Sparrows are vulnerable to parasitism by Brown-Headed Cowbirds, which lay their eggs in the sparrows’ nests. In some Iowa and Illinois study areas, 50 percent to 80 percent of all nests contained cowbird eggs. In areas with high rates of parasitism, Field Sparrows physically attacked models of cowbirds placed near their nests; where little parasitism occurs, the sparrows showed only a mild reaction to the models.
- In winter Field Sparrows may form mixed feeding flocks with other species, including White-throated and Song Sparrows. Smaller and less aggressive than other sparrows, Field Sparrows are usually at the bottom of the dominance hierarchy in these mixed flocks. Their subordinate role means that they may have to take extra risks to gain access to food, such as returning to a feeding site first after a predator has flushed the flock.
- The oldest recorded Field Sparrow was at least 10 years, 4 months old when it was recaptured and rereleased at a banding station in Maryland in 2007. It had been banded in the same state in 1999.
Field Sparrows seek out open habitat with low perches, such as abandoned agricultural fields and pastures, fencerows, road and forest edges, and openings in wooded areas. You may also spot them occasionally in Christmas tree farms, orchards, and nurseries. They’ll breed in fields that were recently burned or cultivated as long as there are some trees or other perches available, but will abandon such settings as thickets of trees grow back. Shy around human habitation, Field Sparrows avoid breeding near where people live. In winter, look for them in settings similar to their summer habitats: abandoned fields and pastures, forest edges, and fencerows. In migration they’ll occasionally turn up in suburban yards.
Field sparrows eat mainly grass seeds in winter, then switch to a blend of seeds and insect prey as the weather warms. Their small bills limit them to small seeds, including those of crabgrass, panic grass, foxtail, and horseweed. Insects make up about half of the summer diet. Prey includes butterflies, weevils, beetles, grasshoppers, cicadas, and spittlebugs, as well as spiders and snails. Parents feed nestlings a diet of spiders and insects, including caterpillars, grasshoppers, flies, bees, and beetles.
- Clutch Size
- 1–5 eggs
- Number of Broods
- 1-5 broods
- Egg Length
- 0.6–0.8 in
- Egg Width
- 0.4–0.6 in
- Incubation Period
- 10–17 days
- Nestling Period
- 5–8 days
- Egg Description
- White to creamy, spotted with pale purple, reddish-brown, or gray.
- Condition at Hatching
- Helpless, eyes closed, with sparse, mouse-gray down along feather tracts.
Only the female Field Sparrow builds the nest, although her mate may help by offering nesting material. Working mainly from early to late morning, she first weaves a framework of crisscrossed grass stems, then constructs an open cup combining coarse and fine grasses lined with grass, rootlets, and hair. It takes 5–8 days to build the season’s first nest; subsequent nests take only 2–3 days to complete. The finished nest measures 3.3 to 8.3 inches across and 1.9 to 4.3 inches high, with a cup depth ranging from 1 to 2.4 inches.
Female Field Sparrows examine several potential nest sites before settling on a location. In spring, nests are often built on the ground in a clump of grass or at the base of a shrub, where they’re less visible. Once grasses get taller and bushes and trees begin to leaf out, Field Sparrows build subsequent nests a foot to as much as 10 feet off the ground, where they’re less accessible to snakes and other predators. Nest sites include blackberry bushes, stands of St. John’s wort, honeysuckle, and coralberry, as well as in dogwood, redcedar, hawthorn, and elms. Field Sparrows avoid human habitation when selecting a nest site.
Field Sparrows hop on the ground as they forage for seeds and insects, often near shrubs or other cover. Like other small sparrows, they have a distinctive style of feeding on grass seed heads: a bird flies to the top of a tall grass stem, then uses its weight to “ride” the stem to the ground, where it pins the seed head and plucks individual seeds. Field Sparrows also pounce on insect prey from low perches. Male Field Sparrows arrive on the breeding grounds 10 to 20 days ahead of females and set up exclusive territories, often spending hours chasing other males along disputed boundaries. Pairs form within a day or two of the females’ arrival. Although Field Sparrows are almost always monogamous, first-time breeding males that form pairs late in the season may end up feeding a nestling that was fathered by a different male. Following the breeding season, Field Sparrows form loose flocks that winter in fallow fields, pastures, and along roads and forest edges.
Field Sparrows are common, although their populations have dropped considerably in the last 50 years. Between 1966 and 2015 the North American Breeding Bird Survey estimated a decline of over 2% per year, amounting to a cumulative decline of 69% during that time. Partners in Flight estimates a global breeding population of 7.6 million, with 98% spending at least part of the year in the U.S., 2% breeding in Canada, and 5% wintering in Mexico. The species rates a 12 out of 20 on the Continental Concern Score, and the 2014 State of the Birds Report lists Field Sparrow as a Common Bird in Steep Decline, but it is not on the 2016 State of North America's Birds' Watch List. The Breeding Bird Survey records an average increase in only one region of North America, the Prairie Pothole region. This may be due to the grassland habitat protection efforts of the Conservation Reserve Program, funded by the Farm Bill. Field Sparrows tend not to nest in human-dominated landscapes such as tilled agricultural fields and suburbs; the great expansion of human development in recent decades has likely permanently reduced the area available to Field Sparrows for breeding. Field Sparrow habitat can best be maintained by protecting some woody vegetation in fields undergoing succession, and by thinning shrubs and saplings in forested habitat to maintain openings.
- Carey, M., D.E. Burhans, and D.A. Nelson. 2008. Field Sparrow (Spizella pusilla). In The Birds of North America Online, No. 103 (A. Poole, Ed.). Cornell Lab of Ornithology, Ithaca, New York.
- C. Elphic, J. B. Dunning, Jr., and D. A. Sibley (eds.). Alfred A. Knopf, New York.
- Dunning, J. B., Jr. 2001. New World sparrows. In The Sibley Guide to Bird Life and Behavior,
- Evans, F.C. 1964. The food of Vesper, Field, and Chipping Sparrows nesting in an abandoned field in Southeastern Michigan. American Midland Naturalist, 72:1, 57-75.
- North American Bird Conservation Initiative, U.S. Committee. 2014. State of the Birds 2014 Report. U.S. Department of Interior, Washington, DC.
- North American Bird Conservation Initiative. 2016. The State of North
America’s Birds 2016. Environment and Climate Change Canada: Ottawa, Ontario.
- Partners in Flight. 2012. Species assessment database.
- USGS Patuxent Wildlife Research Center. 2016. Longevity Records of North American Birds.
- USGS Patuxent Wildlife Research Center. 2015. North American Breeding Bird Survey 1966–2015 Analysis.