Justification The continuing reduction in the extent, area and quality of this species's wintering habitats, as a result of agricultural conversion, logging and charcoal production, is thought to be causing a rapid population decline, qualifying it as Vulnerable.

Family/Sub-family Turdidae

Species name author (Ridgway, 1882)

Taxonomic source(s) AOU checklist (1998 + supplements), Stotz et al. (1996)

Taxonomic note Catharus minimus (Sibley and Monroe 1990, 1993) has been split into C. minimus and C. bicknelli following AOU (1998).

Identification 16-19 cm. Small thrush. Buffy-brown upperparts. Bold black spotting on sides of throat and creamy-buff breast. Rest of underparts white. Greyish cheeks and lores, and dark reddish-brown tail. Similar spp. Smaller than Grey-cheeked Thrush C. minimus, and browner above with paler lores, buffier on breast and has yellow (not pink) on lower mandible. Swainson's Thrush C. ustulatus shows distinct eye-ring. Veery C. fuscescens is redder above and more finely spotted below. Hermit Thrush C. guttatus shows rufous tail. Voice Song, high-pitched chook-chook wee-o wee-o wee-o-tee-t-ter-ee descending at end. Call, harsh slurred whistle. Hints Best located by song in breeding areas.

Population estimate

Population trend

Range estimate (breeding/resident)

Country endemic?

21,000 - 53,000

decreasing

38,600 km²

No

Range & population Catharus bicknelli breeds patchily in south-east Quebec and the Maritime provinces, Canada, and eastern New York and northern New England, USA^1,5,6. There are 20,000-50,000 adults in the USA^4,10 and 1,000-3,000 birds in the Maritime provinces², but there have been local extinctions¹⁰. It migrates along the coast to winter in the Caribbean⁷. The stronghold is the Dominican Republic (especially the Sierra de Baoruco and Cordillera Central) and possibly Haiti^7,9. It may also winter in the Blue Mountains of Jamaica, and small numbers occur in Puerto Rico and Dominica. There are three records from Cuba, including one in the Sierra Maestra in 1999^3,10,11.

Important Bird Areas Click here to view map showing IBAs where species is recorded and triggers any of the IBA criteria.

Ecology: It breeds in dense montane forests (above 900 m) of balsam fir Abies balsamae and red spruce Picea rubens, usually near the treeline^1,8, but occupies less than 75% of available habitat¹⁰. In Canada, it also inhabits regenerating clear-cuts and coastal areas with spruce-fir at low elevations¹. In winter, it occurs in moist broadleaved and mixed pine-broadleaved montane forests and secondary woodlands^7,8,9. It nests in June-July (present on breeding grounds May-September), sometimes with high failure rates⁸. It may sexually segregate in winter, with females in "poorer quality" habitats¹⁰.

Threats Acid precipitation may have damaged breeding habitat in the 1960s and 1970s^6,8. On a predicted doubling of carbon dioxide by 2050, atmospheric warming is forecast to eliminate montane spruce-fir^4,10. Ski-resort, communication and wind-power developments potentially threaten local populations^1,8. In Quebec, the widespread practice of thinning renders habitat unsuitable¹¹. Agricultural conversion, logging and charcoal production are rapidly clearing and fragmenting winter habitat^1,10.

Conservation measures underway CMS Appendix II. There is much research activity in the breeding range and, increasingly, the Caribbean. Some important breeding areas and c.50% of sites in the Dominican Republic are actively protected⁹, but recent funding requests for management were turned down. Management and protection of existing reserves and parks is now inadequate¹². A predictive model has been developed and used to generate a population estimate for this species within New Hampshire¹³, and a more general model has been used to predict distribution in the north-eastern USA in order to inform and plan habitat management/alteration decisions¹⁵. New (and expansion of existing) ski-resorts are developed following environmental impact assessment, in a way that mitigates against habitat loss and disturbance¹⁴. One development established a fund for protecting the wintering grounds¹⁴.

Conservation measures proposed Clarify distribution and migration details^1,8. Refine estimates of population size^1,8, potentially by using an existing predictive model and applying it to new areas. Evaluate human impacts on breeding birds¹⁰. Clarify winter segregation¹⁰. Develop strategies to maintain dense stands of regenerating balsam fir in Quebec. Develop management plans for existing, and designate new, reserves in the Dominican Republic^9,10.

References 1. Atwood et al. (1996). 2. D. Busby in litt. (1999). 3. Garrido and Garcia Montaña (1975). 4. K. McFarland in litt. (1999). 5. Ouellet (1993). 6. Phillips (1991). 7. Raffaele et al. (1998). 8. Rimmer (1996). 9. Rimmer et al. (1999). 10. C. C. Rimmer in litt. (1998, 1999). 11. G. Seutin in litt. (1999). 12. C. Rimmer in litt. (2003). 13. Hale (2006). 14. Anon (2006). 15. Lambert et al. (2005).

Further web sources of information

Audubon WatchList

Text account compilers Phil Benstead (BirdLife International), Jeremy Bird (BirdLife International), Matt Harding (BirdLife International), Isabel Isherwood (BirdLife International), Rob Pople (BirdLife International), David Wege (BirdLife International)

Contributors D Busby, K McFarland, Chris Rimmer (Vermont Institute of Natural Science), G Seutin

IUCN Red List evaluators Jeremy Bird (BirdLife International), Stuart Butchart (BirdLife International), Greg Butcher (National Audubon Society), Greg Butcher (National Audubon Society), David Wege (BirdLife International)

Recommended citation BirdLife International (2009) Species factsheet: Catharus bicknelli. Downloaded from http://www.birdlife.org on 10/2/2010

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

To provide new information to update this factsheet or to correct any errors, please email BirdLife

To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums