Data Zone
Justification of Red List category
This species has been undergoing a moderately rapid population decline over the past three generations; therefore, it is considered to be Near Threatened.
Population justification
Partners in Flight (2020) estimate the population size to be 1,800,000 mature individuals.
Trend justification
Partners in Flight (2020) estimate annual rates of decline of ~2.7% between 1970 and 2017, equable to a ~28% decline across three generations (12.3 years). Christmas Bird Count data for 1966-2019 also shows an annual decline throughout the USA of 2.31% (1.30-3.39%), equating to a reduction of 25% (15-35%) over three generations (Meehan et al. 2018), while Canadian Breeding Bird Survey data suggests an annual decline of 3%, or 31% across three generations (Mills 2018).
Short-term trend data however suggests that the rate of population decline has been decreasing in recent years (Meehan et al. 2018; Pardieck et al. 2018). Data from the North American Breeding Bird Survey (BBS) shows an estimated annual decrease of 0.94% for the three generations prior to 2019 (Pardieck et al. 2018), which equates to a decline of 11% over the past three generations. This value is however non-significant, with the 95%-confidence interval ranging from -2.40 to 0.61 (26% decrease to 8% increase over the past three generations). Given this uncertainty and under the assumption that declines are consistent across the range, the overall rate of past decline is here placed in the band 10-29% over the last three generations.
From 2010 on, year-by-year records from BBS on show stable or slowly increasing population trends (Pardieck et al. 2018). Again assuming that trends are consistent across the entire range, the population is currently assessed as stable.
Antrostomus vociferus is a migratory species, breeding from southern central to eastern Canada and through central to eastern U.S.A.. The species overwinters in south-eastern U.S.A., Mexico and into Central America.
During the breeding season the species is predominantly found in low-elevation forested habitats, typically dry deciduous or mixed forests with little or no underbrush, but it also occurs widely in semi-open habitats, including road corridors, rural farmland, and herbaceous and wetland habitats (Slover and Katzner 2016, Cink et al. 2017). The species has been evidenced to be positively associated with lowland forest, herbaceous and wetland habitat at the expense of higher elevation coniferous forest in the central Appalachians (Slover and Katzner 2016) whilst the species also exhibits negative associations with higher elevation Appalachian sites within its range to the north (Hunt 2006). Some lower elevation sites from which the species was identified in the central Appalachians in 2017 were however, actually situated at a greater altitude than the highest elevation sites from which the species was identified in 2006 in the northern Appalachians, suggesting that the species utilised progressively higher elevation sites as your progress southwards through its range (Hunt 2006, Slover and Katzner 2016, T. Katzner in litt. 2020). There is little information about habitat preferences during migration and in the non-breeding range, but in south-eastern U.S.A. it is mainly found in mixed woodland (Cink et al. 2017), occupying forest habitats to a greater degree than agricultural landscapes (Ross and Driscoll 2019). It feeds during moonlit times of the night as well as at dawn and dusk, usually sallying after insect prey (Cink et al. 2017). It nests directly in the leaf litter, not building a nest, and two clutches may be attempted; with the first being in April-early June and the second brood being attempted c.30-35 days after the first (see Cink et al. 2017).
Whilst the species is thought to be able to tolerate some habitat degradation, the predominant threat is considered to be forest loss and degradation (Slover and Katzner 2016). Tracewski et al. (2016) estimate forest loss of ~5.3% across three generations throughout this species's range and it is this loss of forest, predominantly to agriculture and increased pressures from grazing and urbanisation, that is thought to have driven the species's witnessed declines; grazing of forest underbrush (used as nesting cover by the species) by sheep may have led to its disappearance in some areas whilst habitat loss (and by-product increases in predation) due to urbanisation may have led to the species's disappearance from south-east Pennsylvania (Cink et al. 2017). A. vociferus however, requires a mosaic of young forest and open areas for nesting therefore declines are thought to occur not only in response to forest loss, but also through the succession of open habitat and formerly fragmented semi-natural landscapes to dense forest and closure of forest gaps that prevent successful nesting by the species (Hunt 2013, Slaver and Katzner 2016, Cink et al. 2017). The species also sits at the side of roads, which means it is at high risk from traffic collision, and there are untested theories that industrial pollution and pesticide use could be reducing prey abundance (see Cink et al. 2017).
Conservation Actions Underway
This species is listed as a Threatened species in Kansas (Platt 1974), and is placed on the Yellow watch list by Partners in Flight (Rosenberg et al. 2016).
Conservation Actions Proposed
Conduct research to better understand the threats to this species. Plan appropriate measures to aid species recovery. Undertake forest thinning, shrubland maintenance and potentially prescribed burns, to create a mosaic of open forest suitable for nesting, roosting and foraging (Hunt 2013).
Text account compilers
Hermes, C., Everest, J.
Contributors
Artuso, C., Katzner, T., Meehan, T., Symes, A. & Westrip, J.R.S.
Recommended citation
BirdLife International (2024) Species factsheet: Eastern Whip-poor-will Antrostomus vociferus. Downloaded from
https://datazone.birdlife.org/species/factsheet/eastern-whip-poor-will-antrostomus-vociferus on 22/12/2024.
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 22/12/2024.