The Bicknell’s Thrush is the smallest of the North American Catharus thrushes, and was once believed to be a subspecies of the Grey-cheeked Thrush. As an extreme habitat specialist, the Bicknell’s Thrush has a very limited range, breeding primarily in high elevation stunted montane spruce-fir forests of the northeastern U.S. and southeastern Canada. Direct habitat loss due to forestry and energy and recreational development is a primary threat during the breeding season. The high elevation habitats are further threatened as these small mountain top “islands” may disappear with climage change. Pollution from industrial sources may be creating additional challenges for this species, as acidic precipitation limits calcium availability on the breeding grounds and birds are bioaccumulating high mercury loads.
During the nonbreeding season, the Bicknell’s Thrush defends winter territories in the mid and high elevations broadleaf forests of Cuba, Puerto Rico, Jamaica, Haiti and the Dominican Republic. An estimated 80% of the wintering population occurs in the Dominican Republic and Haiti on the island of Hispaniola, where dwindling forest habitat is a significant threat to the species. Habitat loss in the Greater Antilles is primarily driven by forest clearing for both large-scale agriculture and subsistence farming, as well as logging and charcoal production.
Primary Habitats:Breeding: Boreal Forest
Wintering: Tropical Evergreen Forest
Breeding: Changing Forest Conditions, Climate Change, Contaminants
Wintering: Tropical Deforestation, Changing Forest Conditions, Contaminants
Population Loss Since 1970: 15-50%
Urgency/Half Life: unknown
Global Conservation Status: IUCN 2016-3 Red List – Vulnerable
U.S. Conservation Status: Petitioned for listing (decision pending)
Canadian Conservation Status: Threatened (COSEWIC 2009); Schedule 1, Threatened (SARA)
Birds of Conservation Concern: USFWS – Bird of Conservation Concern
|Region||Area Importance||Long-term Population Change||Half Life|
|Atlantic Coast Joint Venture||60%||***||***|
|Canadian Southern Shield & Maritimes Region||35%||***||***|
|Canadian Eastern Boreal Region||5%||***||***|
*** indicates insufficient or unreliable data to calculate a regional long-term change or half-life estimate.
- Join the International Bicknell’s Thrush Conservation Group
- Help monitor populations:
- Protect and restore wintering ground forest habitat; strengthen international partnerships to support these activities
- Implement management guidelines for breeding ground forest habitat
- Develop socio-economic livelihood alternatives to small-scale, shifting agriculture that results in deforestation on the wintering grounds
- Improve institutional capacity for protected-area management, including boundary demarcation and enforcement
- Provide alternative fuels to reduce demand for charcoal production, which is resulting in loss and degradation of wintering ground forest habitat
- Develop mitigation and best-management practices for construction, operation, and maintenance of wind-energy facilities
Species Conservation Plans:
- A Conservation Action Plan for Bicknell’s Thrush. J. A. Hart, C. C. Rimmer, R. Dettmers, R. M. Whittam, E. A. McKinnon, and K. P. McFarland, Eds. International Bicknell’s Thrush Conservation Group. 2010
Key Species References:
Peer Reviewed Papers:
- Ouellet 1993. Bicknell’s thrush: taxonomic position and distribution.
Rimmer and McFarland. 2001. Known breeding and wintering sites of Bicknell’s Thrush.
- Goetz et al. 2003. Multiple paternity and multiple male feeders in Bicknell’s Thrush (Catharus bicknelli).
- Rimmer et al. 2005. Mercury levels in Bicknell’s thrush and other insectivorous passerine birds in montane forests of the northeastern United States and Canada.
- Lambert et al. 2005. A practical model of Bicknell’s Thrush distribution in the northeastern United States.
- Rodenhouse et al. 2008. Potential effects of climate change on birds of the Northeast.
- Townsend et al. 2011. Sex and age ratios of Bicknell’s Thrush wintering in Hispaniola.
- Studds et al. 2012. Stable-hydrogen isotope measures of natal dispersal reflect observed population declines in a threatened migratory songbird.
- McFarland et al. 2013. A Winter Distribution Model for Bicknell’s Thrush (Catharus bicknelli), a conservation tool for a threatened migratory songbird.
- McKinnon et al. 2014. Nest-patch characteristics of Bicknell’s thrush in regenerating clearcuts, and implications for precommercial thinning.
- Deluca and King 2014. Influence of hiking trails on montane birds.
- Ralston et al. 2015. Analysis of combined data sets yields trend estimates for vulnerable spruce-fir birds in northern United States.
- Aubry et al. 2016. Regional patterns of habitat use by a threatened forest bird, the Bicknell’s thrush (Catharus bicknelli), in Quebec.
- Bredin andWhittam 2008. Conserving the Bicknell’s Thrush: Stewardship and Management Practices for Nova Scotia’s High-Elevation Forests.
- Gouvernement du Québec 2014.Protection Measures for the Bicknell’s Thrush in Relation to Forest Management Activities.
- Lambert et al. 2017. Guidelines for Managing Bicknell’s Thrush Habitat in the United States.