Contents: Species, Interesting Facts, Identification, Song, Distribution, Preferred Nesting Habitat, Diet, Nesting Behavior, Nestboxes, Nestbox Location, Monitoring, Nesting Timetable, Longevity, More Info. Photos of Adults, nests, eggs and young.
Species: There are four weakly differentiated subspecies of Carolina Chickadees (Poecile carolinensis, alpha code CACH): P.c. carolinensis, P.c. extima, P.c. agilis, and P.c. atricapilloides.
- caches seeds, often at mid-day, retrieving them within an hour to a few days; may move them around to a new cache (Lucas 1994, Lucas and Walter 1991)
- 2-8 Carolina Chickadees are often part of mixed flocks during non-breeding season with Titmice, Kinglets, Nuthatches, Brown Creepers and Downy and Hairy Woodpeckers.
Identification: An active, acrobatic, common bird with slate gray upperparts (sometimes with an olive tinge), and whitish underparts that may be tinged with gray/brown on flanks. Black bill, legs are gray. Black cap and bib, with white cheeks (which may wear away in June-August). Similar to the Black-capped Chickadee (BCCH) in appearance. CACH has less white on greater wing-coverts, more drab overall, with a smaller head, a shorter tail (overall length of BCCH is 5.25", CACH is 4.75"). Sexes look the same except males are larger. Southern birds are smaller (consistent with Bergmann's Rule.)
Song: Call chickadeedeedeedee is higher pitched and more rapid than the BCCH, (Sibley) and notes are shorter in duration (BNA). It's hard to tell the songs apart, especially with hybrids.
Distribution: Live farther south than BCCH, in SE and South Central US. See BBS Map. In areas where ranges overlap, they often hybridize. Only 40-60% survive the winter. During the winter, they flock and forage together. They are not migratory. Populations are stable in most areas except GA, FL, LA, SC, TX and VA where there has been a 1-5% decline (Sauer et al 2001, Ringler 1996)
Preferred Nesting Habitat: Multi-layered forest with a healthy shrub, midstory, and overstory canopy - swamp forests, maritime/riparian hardwood forests, hardwood and pine. In Great Plains states found in tree-shrub-savannah communities, ranch land. Coastal plains, swamps. Inhabits parks, well-wooded suburban and urban areas. Will nest under canopy as well as in open areas, may prefer edge of open grassland.
Diet: 80-90% of diet is insects (butterflies, moths, caterpillars, bugs, bees, ants, wasps, aphids, treehoppers, leafhoppers) and spiders in the spring, summer and fall. In winter about 50% of their diet is seeds and fruits (Brewer 1963)- especially poison ivy, blackberry and blueberry. Also fruit/seeds of pine, mulberry, honeysuckle, ragweed, redbud, and Virginia creeper. Sometimes hammers or rips prey apart with bill.
Nesting Behavior: They become territorial in late winter/early spring through late summer (less so after spring.) They are generally monogamous, with pair bonds formed during non-breeding season while in flocks. Pair bonds can last for more than two years.
Nestboxes: See specifications. They will nest in cavities, snags, nestboxes, tubes and fence posts. CACH's have been reported nesting in:
- 4" round PVC (Gilbertson) style, mounted at 10', which they may prefer. Have also used NABS style boxes, wren house.
- boxes with variable distance from bottom of entrance hole to nestbox floor: 4.75, 5, 5.5, 5 and 7 inches.
- Height off the ground reported at 5, 5.5, 6, 7, 9.5 and 10 feet.
- boxes mounted on EMT poles or maple tree.
- Boxes facing North
- Boxes very near houses (e.g., in backyards.)
- Entrance holes for natural cavities averaged 40.2 x 44.7 mm (36 x 55 mm in Illinois). Internal cavities averaged 65.2 mm, with 179 mm depth. (Brewer 1961, BNA)
- They may like hanging boxes better than bluebirds do.
When given the option of using 1&1/4" entrance holes or the 1&9/16" round holes they always used the larger holes for the past three years. They & tufted titmice preferred higher mounted nestboxes in the 8 foot to 14 foot height over boxes mounted 4 feet to 6 feet off the ground. Unlike BCCH's, they don't seem to prefer boxes filled with sawdust that they can then "excavate." (Klyver 1961)
When not breeding, they may roost singly in natural shelters/cavities/nestboxes, entering quickly and quietly before sunset and leaving shortly after sunrise. These roosts are not used for nesting.
Nestbox Location: Under mixed forest canopy and in open areas, although may prefer edge areas near open grassland, just inside a grove of trees or in the afternoon shade of trees and not in direct sun in hot climates. Proximity to bodies water does not seem to be a factor. Have nested away from water bodies, and within 1/4 mile of a water body. Within 100 yards of a house in a residential area with scattered trees, 6 feet from residential street. They don't seem to mind humans, and often use boxes in backyards.
Recommended distance between nestboxes:
- Have nested in boxes that were 400-700 yards apart. In PA, nests in plastic tubes were ~25 feet apart although there was some aggression between the nesting pairs. They have not used paired boxes ~5 feet apart. (BNA)
Monitoring: Nests are sometimes abandoned. Because of the fur plug on top of eggs, a monitor may not realize egg laying or incubation have begun. The CACH female may sit tight on the nest when the box is opened.
Other tips relative to Black-capped Chickadees which MAY apply to MOCHs: Tap the box or whistle to let a brooding female know you are approaching the box - otherwise she may fly into your face. Chickadee egg shells have a very thin shell, and can break even from a light touch. Chickadees are prone to early fledging if disturbed. It's probably a good idea not to open the box after they are 10-11 days old. After that date, you could look in with an automotive mechanic's mirror if you are concerned.
Nesting Timetable (typical):
- Excavation or nest site selection: CACH can excavate their own nest, or will use existing cavities (making them both primary and secondary cavity nesters.) Pair inspects several sites before selection. May start excavation and nest-building at several sites before selecting final location. Excavation and nest building start about 20 days before the first egg is laid, from January - April, depending on the location. Both the male and the female excavate, but one may be the primary excavator (usually the female.) Most breed the first spring after birth, but sometimes in the second spring.
- Nest construction: May occur immediately or a few days after excavation is complete. The nest is mostly constructed by the female, although the male may bring in some nest material. It is very difficult to distinguish from Black-crested Titmouse nest, except there is more hair in the CACH nest, and often dried leaves mixed in with moss in the CACH nest. Nest base of moss, sometimes with strips of bark, thickly lined with grass, plant fibers, fur, hair (e.g., rabbit deer, squirrel, opossum, raccoon, cow, cat). More lining may be added after egg laying/incubation begins. See photos.
- Egg laying: Usually 6 eggs (range 3-10) laid in March-April, usually one per day (rarely skipping a day.) Tiny eggs are ovate to rounded ovate, white, finely marked with reddish-brown dots, spots or blotches, often concentrated on the larger end, with little or no gloss. Clutches may be smaller as it gets later in the season.
- Incubation: 12-15 days. (average 13). Begins with the last or sometimes the penultimate egg. Sometimes breeding males develop a small "brood" patch (BNA), but only the female incubates. Female covers eggs with a fur plug/blanket when she leaves the nest. She roosts with the plug down.
- Hatching: Often asynchronous, over a 2-3 day period. Parents remove empty eggshells, usually leaving infertile eggs behind.
Both parents feed the young.
Nestlings over 10 days old are not removed from the nest.
- Day 0: altricial, except for wisps of down on head, wings and rump, with rich pinkish white/salmon colored skin. Gape flanges are white, mouth light yellow. Few fecal sacs removed during first 4 days.
- Day 9: Female stops brooding.
- Fledging: 16-19 days after hatching, usually in the morning. May take place over a 3 day period. (BNA). May land about 40 m away from the nest after the first flight. They depend on the parents for about 2-3 weeks after fledging.
- Dispersal: Within 2 months of fledging, probably >1 to 8 km from where they were born (BNA)
- Number of broods: Usually one per year. Replacement clutches and second brood attempts are rare.
- Longevity: 10 years 11 mo (Clapp et al 1983.) Annual survival rate probably around 38-60% (based on recapture of banded birds - BNA).
- Nest site fidelity: They do not use roost sites for nesting. They may reuse a nest site the next year, even when one member of the pair is replaced, or a nearby nest site. Keith Kridler reported Carolina Chickadees building a complete nest, but before they laid eggs they found another nest site and moved all but a few tiny pieces of the green moss to the other nestbox about 120 feet away.
References and More Information:
- Input provided by Dan Hanan (TX), Pauline Tom (TX), Keith Kridler (TX), Terri Williams (NC)
- Photos of Adults, nests, eggs and young, Sialis.org
- All About Black-capped Chickadees, Sialis.org
- All About Mountain Chickadees, Sialis.org
- Nest and Egg ID (with links to species biology and photos of nests, eggs and young) for other small cavity nesters
- Dummy and Abandoned Nests, Sialis.org
- All About Birds: Carolina Chickadee, Cornell
- Mostrom, Alison M., Robert L. Curry and Bernard Lohr. 2002. Carolina Chickadee (Poecile carolinensis), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/636 doi:10.2173/bna.636