Mexican Chickadee (Poecile sclateri)

Breeding behavior is not well known. Nest: Site is in hole in tree, usually 10-40′ above ground, someti mes higher; can be just a few inches up in stumps. Adults may enlarge natural cavity, but details poorly known. Also will use birdhouse. Nest (apparently built by female) has foundation of bark fibers and moss, lining of soft moss, animal hair. Eggs: 5- 9. White, with reddish brown dots concentrated at larger end. Incubation is by female only, incubation period not well known. Female may cover eggs with nest material when leaving nest. Male feeds female during incubation period. Young: Female broods young at first, while male brings most food; later, both parents feed young. Adult may sweep outside of nest entrance with crushed beetles; chemicals from these insects may help repel predators. Age of young when leaving nest not well known.

Feeding habits

Mostly insects, probably some seeds. Diet is not well known but probably consists mostly of insects, including caterpillars, beetles, and others. Probably also eats seeds. Behavior: Forages mostly by hopping among twigs and branches and gleaning food from surface, often hanging upside down to reach underside of branches. Sometimes takes food while hovering, and occasionally catches flying insects in midair. May hammer on galls with bill to break them open and pull out insect larvae. Unlike many chickadees, not known to store food.

Conservation

This species has a very large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.

Migration

Resident, Chiricahuas, southeastern Arizona; Animas Mountains, southwestern New Mexico; to Oaxaca. Migration: Mostly a permanent resident. In Chiricahua Mountains, Arizona, some birds move down into lower canyons in winter, may rarely reach adjacent low ranges.

Distribution map