Sitta pusilla

Sitta insularis (Bahama Nuthatch) was formerly considered conspecific with S. pusilla, but separated based on differences in vocalizations (Hayes et al. 2004, Boesman and Collar 2020) and reduced response of each species to playback of vocalizations of the other (Levy and Cox 2020) (AOS 2021).

This species is widespread and abundant in the southeastern U.S. The population suffered severe historical declines due to the loss of longleaf pine forest habitats but the population trend has since stabilized. Although acreage of longleaf pine forest has increased since the mid-20th century, the population continues to face threats of habitat loss and habitat degradation.

This species is a resident of the southeastern United States from eastern Texas and very southeastern Oklahoma, east to the Atlantic Coast including peninsular Florida, and extending northward into extreme southeastern Tennessee, North Carolina, southeastern Virginia, southeastern Maryland, southern Delaware, and southern New Jersey (Slater et al. 2013, Greenlaw et al. 2014, Shoch et al. 2020, McConnell 2024). The highest breeding densities occur in western South Carolina, western Georgia, north peninsular and panhandle Florida, and southern Mississippi (Slater et al. 2013, Greenlaw et al. 2014). Using Global Biodiversity Information Facility (GBIF) (2025) records, range extent is estimated to be 1.934 million km² (RARECAT 2025).

Populations from the Bahamas are now considered a separate species, S. insularis (Hayes et al. 2004, Boesman and Collar 2020, Levy and Cox 2020, AOS 2021).

Restricted to the eastern United States but is often common and widespread where suitable habitat remains.

Declines seem strongly linked to reductions in natural pine forest as plantation acreage has increased, fires have become less frequent, and fewer farms have been abandoned (Withgott and Smith 1998, Wilson and Watts 1999). Short rotations for timber production reduce forest openings and tree size, while fire suppression reduces snag formation and allows for increased growth of deciduous trees and shrubs (Meyers and Johnson 1978, Engstrom et al. 1984). Pine plantations are known to be entirely unsuitable or minimally suitable habitat (Wilson and Watts 1999). Fire exclusion results in declining habitat conditions, including providing fewer snags (standing dead tree trunks) (Lloyd and Slater 2007). Coupled with the problem of habitat loss is that of habitat fragmentation. Recolonization occurs slowly or not at all. Apparently suitable habitat on the edges of the range remains vacant.