Justification of Red List Category
This species has been downlisted from Vulnerable on the basis of recent information about its population size. It is listed as Near Threatened because it is estimated to have a moderately small population, which is precautionarily suspected to be in slow decline based on known threats and local trends.
The population has been estimated at 15,000 individuals (Rosenberg et al. 2016), having been estimated at 14,068 in 2003 (U.S. Fish & Wildlife Service 2003) and c. 14,500 based on 2008 data (W. McDearman in litt. 2010), thus the population is placed in the band for 10,000-19,999 mature individuals, assumed to be equivalent to c. 15,000-30,000 individuals in total.
This species underwent a large and statistically significant overall decrease estimated at 81% between 1970 and 2014 (Rosenberg et al. 2016), and James (1995) calculated a 23% decline in the number of clusters between the early 1980s and 1990. More recently, some large areas of Federal land have demonstrated increases in both the number of individuals and of clusters as a result of intensive management (U.S. Fish and Wildlife Service 2008, W. McDearman in litt. 2010). For example, between 1994 and 2002, populations increased by as much as 50% at six military installations (U.S. Fish and Wildlife Service 2008). As a result of conservation action, the overall population may currently be stable, and could be increasing overall, although some sub-populations are known to still be in decline and losing their viability (W. McDearman in litt. 2010). Until the situation is clarified, an on-going slow decline is precautionarily suspected, on the basis that further cluster losses may be occurring in some sub-populations.
This species was originally distributed throughout the southeastern USA; however from the late 1800s to the mid-1900s, it declined rapidly due to the extensive alteration of mature pine forests (U.S. Fish and Wildlife Service 2008). During the late 20th century it continued to decline, undergoing a large and statistically significant overall decrease between 1970 and 2014 (81% decline, data from Breeding Bird Survey and/or Christmas Bird Count [Rosenberg et al. 2016]), and James (1995) calculated a 23% decline in the number of known sites (clusters, groups of trees actively used by potential breeding groups of mature woodpeckers) between the early 1980s and 1990. In 1999, it was limited to c. 30 isolated populations (the largest in South Carolina and Florida), totalling c. 4,700 groups or c. 11,000 individuals and occupying just 4,000 km2 (Jackson 1994, Guynn 1997, J. A. Jackson in litt. 1999). However, the most recent population estimates suggests that the population now exceeds 10,000 mature individuals, with an estimate of 15,000 individuals in 2016 (Rosenberg et al. 2016), up from 14,068 individuals, arranged in 5,627 clusters (U.S. Fish and Wildlife Service 2003). The unusual co-operative breeding biology of the species means that the actual number of reproductive units is lower than that expected from the estimate of mature individuals (D. Wood in litt. 2016). Hence while the overall population may now be stable with the targeted recovery populations increasing (Department of Defense/U.S. Fish and Wildlife Service in litt. 2006, U.S. Fish and Wildlife Service 2008, W. McDearman in litt. 2010), the structure of the population, documented local declines and the continued loss of some clusters suggest that the precautionary approach is to continue to suspect an on-going, slow overall decline. Its apparent recovery in many areas is the result of successful conservation efforts, including habitat management, nest-site provision and translocation of birds (U.S. Fish and Wildlife Service 2008), whilst improved knowledge has been acquired thanks to intensive studies. It is not clear if such management ceased that habitat improvements are yet sufficient to support continued population increases without the additional intensive management (J. R. Walters in litt. 2013).
It inhabits fire-sustained open pine-forest, dominated in half of its range by longleaf pine Pinus palustris and elsewhere by shortleaf P. echinata, slash P. elliotti, or loblolly P. taeda pines (J. A. Jackson in litt. 1999). It is a cooperative breeder, with each group requiring at least 80 ha of habitat (Walters et al. 1988, U.S. Fish and Wildlife Service 2003). Nesting trees appear to be selected on the rate and duration of fresh resin production, utilised by the birds to protect their nest holes from arboreal predators, such as climbing rat snakes Elaphe obsoleta (Jackson 1994). The selected tree also needs a sufficiently large, living heartwood which is infected with red heart fungus, so the tree must be over 80 years old (often 100+, age of suitability varies by pine species) (U.S. Fish and Wildlife 2003). Groups are typically comprised of a pair and up to five adult helpers, which are mostly offspring from previous years and mostly male as dispersal is female-biased (Jackson 1994, Conner et al. 2001). Eggs are laid from late April to early June (Winkler et al. 1995). Foraging habitat preferences differ between the sexes and females are negatively influenced by the loss of old-growth trees (Jackson 2000). One study showed that adults were heavier, and both adults and nestlings apparently sourced more food in shortleaf and loblolly pine habitats than in longleaf pine forest (Schaefer et al. 2004).
Because of its biology and dependence on old-growth forest, this species is said to be uniquely susceptible to rapid declines under inappropriate management regimes (J. R. Walters in litt. 2013). The long-term clearance and economic management of habitat has reduced the viability of all populations. From the late 1800s to the mid-1900s, the species decreased rapidly as mature pine forest was altered, primarily for timber harvest and agriculture (U.S. Fish and Wildlife Service 2008). Longleaf pine communities in the southeastern USA may have originally covered c. 24-37 million ha, but today fewer than 1.2 million ha remain (U.S. Fish and Wildlife Service 2008). The excessive cutting of old-growth forests is reported to still be taking place in some areas (J. A. Jackson in litt. 2012). Suppression of the natural fire regime allowing an increase in mid-storey hardwood density has rendered large areas of habitat unsuitable for the species (U.S. Fish and Wildlife Service 2003), increasing population fragmentation. This has isolated nest-sites, making abandonment or group extirpation increasingly likely (Thomlinson 1995); translocation of these isolated groups for population augmentation elsewhere makes the loss of the site certain. Translocation of birds to federal lands may also swamp locally adapted gene pools (J. A. Jackson in litt. 1999). Inbreeding depression has been highlighted as a potentially serious problem in small and isolated populations (Schiegg et al. 2006), and may be exacerbated by female-biased dispersal in small and fragmented populations (Dale 2001) which appears the case for the species (Daniels 2000). Fire management (involving regular burning) has aided habitat restoration, but as human populations expand there is increasing pressure to suppress fires. Exempting landowners from the Endangered Species Act has resulted in rapid declines on private land (J. A. Jackson in litt. 1999). Loss of nesting cavities to Southern flying squirrels Glaucomys volans may contribute to breeding site limitation, as may cavity enlargement by Pileated Woodpecker Hylatomus pileatus and Yellow-shafted Flicker Colaptes auratus (U.S. Fish and Wildlife Service 2003, Saenz et al. 2008). Southern pine beetle Dendroctonus frontalis infests cavities and kills nesting trees (Conner and Rudolph 1995, U.S. Fish and Wildlife 2003) (although they have a positive effect on woodpecker foraging both as a food item, and by creating arthropod rich dead-wood habitat [Schaefer et al. 2004]). Beetle infestations have increased since habitat management for the woodpecker started in 1988, suggesting a possible connection (Conner and Rudolph 1995).
Conservation Actions Underway
The emphasis has been on site-specific rather than ecosystem-level management (J. A. Jackson in litt. 1999). Intensive activities include translocating young females from natal sites to groups lacking a female, constructing artificial cavities (Jackson 1994), and fitting restrictor plates to prevent D. pileatus enlarging cavities (Saenz et al. 1998). Adults have also been successfully translocated from sites that have been allowed to become isolated, and can augment the population in the receptor sites but with lower success than for the translocation of young birds (Harbez et al. 2011). Habitat is managed (regular burning and understorey clearance) on some federal lands, but not always appropriately (Jackson 1994). The U.S. Fish and Wildlife Service developed the Red-cockaded Woodpecker Foraging Matrix Application in 2004, which uses a habitat suitability modelling approach to assess the ability of sites to sustain populations via quantitative assessments of stand-level and territory-level habitat quality (McKellar et al. 2014). This has been used to assess potential impacts of projects that may affect foraging habitat, such as development, harvesting or modification (e.g. thinning of pine stands) (McKellar et al. 2014). In South Carolina the Safe Harbor scheme offers financial incentives to private landowners who undertake beneficial management prescriptions (Duncan et al. 2001). Local population increases have been dependent on intensive management (J.R. Walters in litt. 2013).
22 cm. A rather small black-and-white woodpecker with longish bill. Above black barred white. Below white with black spots or streaks on flanks. Black crown, nape and moustachial stripe border white cheeks and side of neck. Male has a few tiny red feathers (usually hidden) on the side of crown. Juvenile duller black with variable extent of red on center of forehead, juvenile female with flecks of white on forehead, especially near the bill. Similar spp. Hairy Woodpecker P. villosus usually lacks ladder-backed appearance and white cheek patch. Voice Drumming infrequent and not loud. Distinctive shrrit call most commonly heard, also a rattle and wide range of social twittering and chortles. Hints Active nest and roost-trees have distinctive sap flows from small, shallow holes excavated above and below the cavity.
Text account compilers
Taylor, J., Benstead, P., Wege, D., Bird, J., Calvert, R., Martin, R, Isherwood, I.
Wood, D., Walters, J., Jackson, J., McDearman, W.
BirdLife International (2019) Species factsheet: Leuconotopicus borealis. Downloaded from http://www.birdlife.org on 17/11/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 17/11/2019.