Justification of Red List Category
This species has declined rapidly in southern parts of its breeding range in recent years. Northern populations faired better but overall moderately rapid declines have been recorded. Therefore, it qualifies as Near Threatened, but if declines continue to worsen in the north of its breeding range it may warrant uplisting to Vulnerable in the future.
Rich et al. PIF North American Landbirds Conservation Plan (2004).
This species has undergone a large and statistically significant decrease over the last 40 years in North America (-63.8% decline over 40 years, equating to a -22.4% decline per decade; data from Breeding Bird Survey and/or Christmas Bird Count: Butcher and Niven 2007). Declines have been particularly marked over the past 15 years (Buehler et al. 2007).
Vermivora chrysoptera breeds from southern Manitoba, Ontario and Quebec, Canada, and northern New York, southern Vermont and eastern Massachusetts, USA, south through the eastern USA to Tennessee, Georgia and South Carolina (AOU 1983, Buehler et al. 2007). Birds winter from the Yucatán Peninsula (Mexico and Belize) and Guatemala, south through El Salvador, Honduras, Nicaragua, Costa Rica and Panama to northern and eastern Colombia and northern Venezuela (AOU 1983); wintering birds are occasionally recorded from the Bahamas, Cuba, Jamaica, Dominican Republic, Haiti and Puerto Rico (Bond 1979). Although it had increased and expanded its distribution for more than a century, evidence from the North American Breeding Birds Survey suggests that it is declining in its southern range, from Georgia to New England (where decline has been particularly severe) (D. A. Buehler, R. A. Canterbury and J. L. Confer in litt. 2003, Buehler et al. 2007). It increased over the last c.30 years in the northern part of its breeding range (Curson et al 1994, D. A. Buehler, R. A. Canterbury and J. L. Confer in litt. 2003), although recently declines have been recorded (Buehler et al. 2003). Estimates suggest a current population of c.210,000 birds (Rosenberg and Blancher 2003, Rich et al. 2004).
Breeds in open deciduous woodland, secondary growth, brushy pastures and bogs (AOU 1983), apparently favouring a particular stage in woodland succession (Curson et al 1994). When the habitat passes this stage, birds move on (Curson et al 1994). All kinds of woodland and scrub are used during migration, and birds generally winter in secondary growth forest or forest edge with a good understorey (Curson et al 1994). Most records come from below 2,000 m, and right down to sea-level (Curson et al 1994). The well-hidden nest is usually on or close to the ground, and breeding takes place in May and June (Curson et al 1994).
Local declines correlate with advancing succession and reforestation, and the invasive range expansion of Blue-winged Warbler Vermivora pinus (Confer 1992). Other possible causes of population declines are loss of wintering habitat (especially forest edge and open woodland) through agricultural expansion and clearance for plantations, nest parasitism by Brown-headed Cowbird Molothrus ater and hybridisation with V. pinus (Confer 1992).
Conservation Actions Underway
None are known.
Text account compilers
Harding, M., Isherwood, I., Benstead, P., Bird, J., Sharpe, C.J.
Wells, J., Buehler, D., Confer, J., Rosenberg, K., Canterbury, R.
BirdLife International (2022) Species factsheet: Vermivora chrysoptera. Downloaded from http://www.birdlife.org on 04/10/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 04/10/2022.