Justification of Red List category
This species has declined steadily at a moderately rapid rate, and as such it is listed as Near Threatened.
Population justification
Partners in Flight (2019) estimate the population size at 170,000 mature individuals.
Trend justification
Data from the Breeding Bird Survey suggests that between 2010-2015, the species underwent an ~2.52% annual decline, which equates to a ~22.5% decline across the stipulated ten year period (Sauer et al. 2017). Similarly, the Christmas Bird Count (between 1966 and 2017) suggests annual declines of a comparable magnitude, ~2.61% per year, which equates to a ~23.2% decline across the ten year period (Meehan et al. 2018). Finally, Partners in Flight (2019) have given the species a half-life of ~24 years, which equates to an annual decline of ~3.1%, or ~26.8% decline over the next ten years. Given all such calculations. the rate of decline is placed in the range 20-29%.
Peucaea aestivalis occurs on the coastal plain and Piedmont of south U.S.A., from extreme south Virginia to central Florida and east Texas. Occasional birds are reported north to south-central Missouri, Kentucky and Tennessee, and it formerly occurred as far north as south-west Pennsylvania, south Ohio, Illinois and Indiana. Only the northern populations were migratory, reaching as far as North Carolina. In 1890-1915, its range expanded considerably in response to the clearance of old pine forests and the abandonment of farms in the Mid-west. This expansion peaked in 1915-1920, and a gradual decline in the north of its range began in the 1930s, mostly occurring before the 1960s, because of forest succession; P. aestivalis now only appears present at 11% of historic locations in North Carolina (Taillie et al. 2016). Maximum densities of singing males in South Carolina were 0.41-0.48/ha in occupied patches of suitable habitat, but many populations are isolated and prone to local extinction (Dunning 1993, J. B. Dunning and C. E. Shackleford in litt. 1999).
The species breeds in early succession pine woodlands or in mature longleaf pine. It is also found occasionally in open habitats with dense grasses and forbs. Nest site selection can vary according to the region, with individuals in the Coastal Plain area selecting areas with a greater amount of woody vegetation and lower grass densities, and individuals in the Sandhills region selecting sites with intermediate grass density and higher tree basal area (Winiarski et al. 2017b).
The species is now absent over most of its northern range and uncommon in most of the southern part because of timber harvesting practices, fire suppression and fragmentation of suitable habitat, meaning many suitable patches of habitat are not occupied (Jones et al. 2017). It is also subject to disturbance by birdwatchers in parts of its range. Urban development in certain areas may also have an effect, as this will only exacerbate the problem of restoring and implementing fire regimes that are beneficial for this species (P. Taillie in litt. 2016). This species has also been reported as suffering mortality as a result of collisions with communications towers (Longcore et al. 2013).
Conservation Actions Underway
Management practices for Red-cockaded Woodpecker Picoides borealis were thought to benefit this species, and although these species continue to commonly occupy the same sites (Hannah et al. 2015, J. Carpenter in litt. 2020), there is now evidence to suggest this may not be the case. Efforts to restore understorey plant communities in pine flatwoods have proven difficult so far, and as such, little suitable habitat has been restored. However, prescribed burning has been identified as a more cost-effective method of maintaining proper understorey and grass communities than mechanical or chemical control of vegetation and the species's is known to show clear selection for several vegetation characteristics linked to frequent fire in its resident longleaf pine forest habitat (Winiarski et al. 2017a). Furthermore, timber management changes since 2000 within the species's range may provide more habitat in the future. Managing for large trees (sawtimber) is becoming increasingly viable for forest land-owners as opposed to pulpwood; in managing for sawtimber, planting densities are reduced and stand improvement activities maintain grass understorey better than pulpwood plantations (Askins et al. 2007).
15 cm. A medium sized rufous, grey and buff Sparrow. Upperparts grey streaked brown or rufous, head with vague rufous/brown lateral crown strip and grey median crown stripe, breast buff/grey-buff becoming white on the belly, tail dark paler terminally with small white tip (western races generally paler and more rufous with more buffy breast). Juvenile darker with distinct whitish eye-ring. Similar spp. Should not be sympatric with either Botteri's Sparrow A. botterii or Cassin's Sparrow A. cassinii which are most similar, though care should be taken with out-of-range birds; both these species have a more uniform grey crowned appearance. Voice Song a whistle followed by a trill, usually given from a pine tree or bush or sometimes in a song flight. Hints Shy and secretive except when singing, mostly in the early morning and evening, which continues well into the breeding season.
Text account compilers
Everest, J.
Contributors
Bird, J., Capper, D., Carpenter, J., Dunning, J., Meehan, T., O'Brien, A., Shackleford, C.E., Taillie, P., Wege, D. & Westrip, J.R.S.
Recommended citation
BirdLife International (2024) Species factsheet: Bachman's Sparrow Peucaea aestivalis. Downloaded from
https://datazone.birdlife.org/species/factsheet/bachmans-sparrow-peucaea-aestivalis on 24/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 24/12/2024.