Chickadees are small, active birds recognized by their distinctive calls and curious demeanor. These charming birds are frequent visitors to backyards and natural areas across North America. Their year-round presence allows observation of their annual reproductive cycle. Understanding their nesting habits offers a fascinating glimpse into their lives.
The Egg-Laying Season
Chickadees typically begin their breeding season in mid-April, with egg-laying commencing as early as the second week of April for Black-capped Chickadees, extending through early July. The exact timing can vary based on geographical location and environmental factors, such as temperature, with warmer years potentially seeing an earlier start. For instance, in Boston, Black-capped Chickadees may begin laying eggs by the first week of May. Carolina Chickadees start laying eggs in late March and early April, with their breeding season continuing until mid-July. Female chickadees generally lay one egg per day, usually in the morning, until their clutch is complete.
Nesting and Clutch Details
Chickadees are cavity nesters, building nests in tree holes, abandoned woodpecker cavities, or nest boxes. Both male and female chickadees may participate in excavating or enlarging the chosen cavity, which can take 7 to 10 days. The female alone constructs the nest, a process that can take one to two weeks. The nest typically features a foundation of coarser materials like moss, pine needles, or bark strips. The base is lined with softer materials such as animal fur, wool, plant down, or even spider webs, forming a cozy, one-inch-deep cup.
A typical clutch size for chickadees, particularly the Black-capped Chickadee, ranges from 6 to 8 eggs, though it can vary from as few as 1 to as many as 13. Carolina Chickadees typically lay around 6 eggs, with a range of 5 to 8. Eggs are small, measuring approximately 0.65 inches long and 0.59 inches wide for Black-capped Chickadees. They are white to creamy-white, featuring fine reddish-brown dots or spots often concentrated at the wider end. The female often covers the eggs with nesting material when she leaves the nest, likely for warmth and camouflage.
From Egg to Fledgling
Once the female has laid her full clutch, she begins the incubation period, which typically lasts 12 to 13 days for Black-capped Chickadees and 12 to 15 days for Carolina Chickadees. The female is the sole incubator, developing a specialized brood patch—a featherless area of skin that helps transfer her body heat to the eggs. During this time, the male often brings food to the incubating female. All eggs in a clutch usually hatch within 12 to 30 hours of each other.
After hatching, the nestlings are initially blind and mostly naked, with only small patches of downy feathers. For the first few days, the female remains in the nest to brood and keep the young warm, while the male provides most of the food for the entire family. As the nestlings grow and can regulate their own body temperature, both parents share the responsibility of feeding, bringing protein-rich insects.
Young chickadees remain in the nest for 16 to 19 days before fledging. After fledging, the young birds continue to be fed by their parents for an additional two to four weeks as they learn to forage independently.