The State of Bicknell’s Thrush
Regionally: Stable to Slowly Declining
Mountain Birdwatch data suggest that Bicknell’s Thrush populations in the United States have been mostly stable since 2001. Results show a decline between 2011 and 2012, followed by a period of relative stability. Data collected during the first ten years of Mountain Birdwatch indicate a population that was apparently stable or perhaps growing slowly.
Recent declines
Bicknell’s Thrush numbers in the study area declined from 2011-2012, before apparently stabilizing and then gradually increasing until 2016. Faded bars estimate the uncertainty in the estimate of abundance.
Past stability
The average number of Bicknell’s Thrush counted during each survey was stable or grew slowly from 2001-2010. Faded bars estimate uncertainty in the estimate of the number counted.
Globally: Probably Declining
Mountain Birdwatch data tell the story of Bicknell’s Thrush population health in the United States. To understand the global state of Bicknell’s Thrush, we also need to consider data collected in Canada, which is home to a significant number of Bicknell’s Thrush.
In Canada, data collected by the Breeding Bird Survey indicate large declines in the number of Bicknell’s Thrush counted in Quebec and Nova Scotia (data from New Brunswick were not included in the analysis), especially between 1970 and 1990. The number of survey routes on which Bicknell’s Thrush are detected is small and thus confidence in Breeding Bird Survey results is low. However, the second Breeding Bird Atlas of the Maritime Provinces shows recent local extinctions of some coastal populations in Nova Scotia and New Brunswick, which also supports the idea that overall numbers of Bicknell’s Thrush are dwindling.
Bicknell’s Thrush numbers have declined across Canada according to results from the Breeding Bird Survey. Figure provided by Environment Canada.
Opportunities for Conservation
Opportunities for conservation of Bicknell’s Thrush were identified by the International Bicknell’s Thrush Conservation Group. They include addressing the following:
- The clearing and burning of forests in the Dominican Republic and Haiti to create agricultural fields.
- Incompatible forestry practices on the breeding grounds, especially in Canada.
- Climate change.
A complete discussion of the threats facing Bicknell’s Thrush is provided in the updated Conservation Action Plan for Bicknell’s Thrush.
What We Can Do to Help
Breeding habitat
Breeding habitat in the United States and Canada should be conserved by making sure that best-management practices for forestry operations are adhered to whenever logging occurs in areas inhabited by Bicknell’s Thrush. Development in mountain-top breeding areas should be avoided wherever possible.
Wintering habitat
Winter habitat in the Caribbean should be protected by purchasing it and setting it aside for conservation, by developing easement agreements with willing landowners, or by supporting compatible land uses that provide economic returns while protecting the forest ecosystems required by Bicknell’s Thrush. One interesting example of integrating conservation into sustainable development is Reserva Zorzal, a farm in the Dominican Republic. Seventy percent of the land is set aside to provide habitat for Bicknell’s Thrush; the remainder is used to grow cacao, which generates revenue and jobs.
Throughout its range
In the long run, conserving Bicknell’s Thrush will require that we address the climate change caused by our activities. This means supporting government policies – and making individual choices – that lead to a reduction in greenhouse-gas concentrations.
