Chipping Sparrows are small, slender songbirds that are very common across North America. They get their name from their distinct “chip” call that they make repeatedly while foraging for food. Chipping Sparrows are identified by their reddish brown cap, gray face, black line through the eye, and dark-streaked back. Their underparts are pale gray, and they have a long dark tail with white outer feathers.
Chipping Sparrow Nesting
Chipping Sparrows build open, cup-shaped nests out of grass, weeds, twigs, rootlets and lined with hair and fine grasses. They often place their nests in coniferous trees or shrubs, 2 to 10 feet above ground. The female Chipping Sparrow incubates the eggs and cares for the young, while the male defends the territory and brings food to his mate.
The breeding season for Chipping Sparrows is April to August. Chipping Sparrows have 2-3 broods per season and lay between 2-7 eggs per clutch. The eggs are small, measuring approximately 0.6 x 0.5 inches. The eggs are pale blue or greenish-blue in color and speckled with brown or black markings.
Why Chipping Sparrows lay blue eggs
Most bird species lay eggs with some degree of blue, green, or brown pigmentation. The pigments biliverdin and protoporphyrin are what give many birds’ eggs their colorful hues. There are several theories as to why many bird species lay colored eggs instead of white eggs:
- Pigmented eggs may be harder for predators to see in a shadowy nest.
- The pigments may strengthen the eggshell to protect the developing embryo.
- Since blue-green is a common avian eggshell color, it may serve as camouflage to help the eggs blend in with their environment.
- Egg coloration could also have evolved from sexual selection – females may have preferred brighter male mates who passed on genes for bolder egg colors.
So for Chipping Sparrows, laying pale blue eggs likely originally evolved to help hide and protect their eggs in the nest. The blue-green coloration provides camouflage as the eggs blend in with the surrounding nest materials and vegetation. This pigmentation helps reduce the chance of nest predation.
Where do Chipping Sparrows Nest?
Chipping Sparrows are open nesters, building their nests in the branches of trees and shrubs. Some typical nesting sites include:
- Conifers – spruce, pine, fir, juniper
- Small deciduous trees – dogwood, hawthorn, elm
- Shrubs – buckthorn, honeysuckle, sagebrush
Chipping Sparrows often reuse a nesting site in subsequent years. They seem to prefer nesting in conifers, likely because the dense, evergreen branches provide good concealment. The height of nests can range from just a couple feet off the ground up to around 30 feet high.
What materials are used in Chipping Sparrow nests?
Chipping Sparrow nests are made of the following materials:
- Grasses – Provides the bulk of the nest structure. Long, flexible grasses are woven together to form the cup shape.
- Rootlets – Used to reinforce the nest walls and provide stability.
- Twigs – Add structural support to the nest’s exterior.
- Bark strips – Help bind the nest materials together.
- Spider silk – Adds elasticity to the nest.
- Animal hair – The soft lining helps insulate eggs/chicks.
Chipping Sparrows gather these materials from the ground or directly from plants. The nest’s cup measures approximately 2-3 inches across and 1-2 inches deep. Nests are often reused for second broods or in following years.
How many broods do Chipping Sparrows have?
Chipping Sparrows typically raise 2-3 broods per breeding season. Here are some details on their breeding cycle:
- First broods are initiated in April/May after spring migration.
- The female incubates the eggs for 11-14 days before they hatch.
- Chicks fledge from the nest around 9-12 days after hatching.
- After successfully fledging a brood, the parents may raise another clutch.
- Second broods are common, initiated anytime between late May and mid July.
- Some birds may even raise a third brood in July/August before migrating south.
So in a single breeding season, a pair of Chipping Sparrows can potentially fledge up to 21 chicks if they have 3 successful broods! The availability of food resources plays a key role in whether the birds can sustain multiple clutches.
How many eggs do Chipping Sparrows lay?
A typical Chipping Sparrow clutch contains between 2-7 eggs. The average is usually 4-5 eggs per clutch. Clutch size tends to be smaller early and late in the breeding season.
Chipping Sparrows have high rates of nest predation and brood parasitism which can result in them re-nesting multiple times. Smaller clutch sizes may be an evolutionary adaptation to provide safety in numbers for the chicks under risky conditions.
Do both parents incubate the eggs?
Only the female Chipping Sparrow incubates the eggs. She sits tight on the nest while the male stands guard nearby. Incubation lasts for 11-14 days before the eggs hatch.
To incubate properly, the female needs to keep the eggs at a constant temperature between 98-102°F. She rotates the eggs periodically using her feet to ensure even warming. The female leaves the nest periodically to feed and preen.
The male Chipping Sparrow helps feed the female while she incubates. But he does not directly participate in warming the eggs. His role is to vigilantly stand watch and chase away any potential predators that come near the nest.
Do Chipping Sparrows use the same nest for multiple broods?
Chipping Sparrows frequently use the same nest to raise consecutive broods in a single season. The female may add a fresh lining before laying another clutch in the nest. Nest reuse offers these advantages:
- Saves energy – no need to build a whole new nest
- Familiar territory – safer than establishing a new site
- Protected site – reuse locations that previously succeeded
- Time saving – quickly get started on next brood
However, reused nests can accumulate parasites and diseases. So sometimes Chipping Sparrows will construct a new nest nearby to reduce contamination.
Do the males and females look different?
Male and female Chipping Sparrows have identical plumage and appearance. The only slight difference is:
- Females may have a slightly duller cap color compared to males.
- Females average slightly smaller in overall size.
But otherwise, the sexes are monomorphic – there is no sexual dimorphism in Chipping Sparrows. Even experienced birders have a very difficult time telling males and females apart.
During courtship however, the males will display and sing to attract a mate. So male behavior provides the main clues to differentiate gender.
How do the chicks develop in the nest?
Here’s a summary of Chipping Sparrow chick growth and development in the nest:
- Day 1 – Chicks hatch blind, naked, helpless. They weigh just 0.5g and can’t even lift their heads.
- Day 3 – Pin feathers start growing in, eyes begin opening. Chicks can lift their heads.
- Day 5 – Eyes fully open, bodies covered in downy feathers. Weights about 5g.
- Day 7 – Rapid feather growth continues, wings start to develop. Beg loudly for food.
- Day 9 – Primaries emerging on wings and tail. Down still prominent. 10-12g weight.
- Day 11 – Juvenile plumage set, ready to fledge. Weigh 12-15g.
The chicks grow incredibly quickly, transforming from helpless hatchlings to fully-feathered fledglings in just 10 days! Proper nutrition provided by both parents ensures rapid development.
Do the parents continue caring for the chicks after they leave the nest?
Yes, once the Chipping Sparrow chicks fledge from the nest at 9-12 days old, the parents continue caring for them for several weeks. The fledglings cannot forage independently yet, so the parents provide ongoing care:
- The fathers remain vigilant, protecting the young from predators.
- Both parents gather food and feed the fledglings for 2-3 more weeks.
- They lead the juveniles to good foraging spots to teach food-finding skills.
- Adults give alarm calls to warn fledglings of danger.
- Parents may offer additional nighttime brooding for warmth and safety.
This extended parental care period helps ensure the young sparrows can survive until they gain full independence in about a month after fledging the nest.
What threats do Chipping Sparrows face?
Some of the main threats Chipping Sparrows encounter include:
- Nest predation – Common nest thieves include snakes, squirrels, chipmunks, raccoons, and domestic cats.
- Brood parasitism – Brown-headed Cowbirds lay eggs in Chipping Sparrow nests, reducing success.
- Severe weather – Storms, hail, prolonged rain can destroy nests and eggs.
- Habitat loss – Reduced breeding grounds from development, logging, and agriculture.
- Vehicle strikes – Sparrows are vulnerable while feeding on roads.
- Pesticides – Can reduce insect food sources and cause reproductive issues.
Supporting Chipping Sparrows involves protecting brushy habitats, keeping cats indoors, and reducing pesticide usage. Still, Chipping Sparrows remain one of the most abundant and thriving songbird species across North America.
Conclusion
In summary, Chipping Sparrows are small songbirds that build open cup nests, often in conifers. The female incubates 2-7 pale blue eggs for about 12 days before they hatch. Chipping Sparrows frequently raise 2-3 broods per season. Both parents work together to feed and protect the helpless chicks. After fledging from the nest, the young are cared for by their parents for several more weeks. Understanding details about Chipping Sparrow breeding and nesting habits provides insight into the adaptations and reproductive strategies of these common North American songbirds.