A project of

Blackpoll Warbler

Champion Migrant

Blackpoll Warblers are renowned for their migratory prowess. Each fall, they undertake non-stop flights of more than 2000 km en route to their wintering grounds in South America. One of the most common birds of the boreal forest, recent years have seen substantial declines in their numbers.

The State of Blackpoll Warblers

Regionally: Probably Declining

Mountain Birdwatch data paint a mixed picture for Blackpoll Warbler. Results show a steep decline in recent years in the mountains of the northeastern United States. Data collected during the first ten years of Mountain Birdwatch, however, show an apparently stable population.

Recent declines

Blackpoll Warbler numbers in the study area declined each year from 2011-2015, before apparently stabilizing at low numbers in 2016. Faded bars estimate the uncertainty in the estimate of abundance.

Past stability

The average number of Blackpoll Warbler counted during each survey was stable from 2001-2010. Faded bars estimate uncertainty in the estimate of the number counted.

Globally: Probably Declining

Overall, Blackpoll Warbler appears to have been declining in numbers for many decades. Data collected by the Breeding Bird Survey indicate large declines in the number of Blackpoll Warblers counted across Canada (where most of the population lives), especially between 1970 and 1990. This species is very difficult to monitor, however, because its core breeding habitat is so remote and inaccessible. As such, confidence in these estimates is low.

Blackpoll Warbler numbers have declined across Canada according to results from the Breeding Bird Survey. However, uncertainty in these estimates is quite high and confidence low as to the exact magnitude of the decline. Figure provided by Environment Canada.

Opportunities for Conservation

Scientists have not studied Blackpoll Warblers sufficiently to understand where and how to target conservation interventions. Although we know much about their spectacular migration, other phases of their life cycle remain a mystery. Mountain Birdwatch is the only monitoring program that rigorously tracks Blackpoll Warbler populations, but it covers only a small part of the species’ range. As such, we cannot say for sure how the population has changed or what specific threats it faces.

What We Can Do to Help

Most importantly, we need more monitoring and research. In particular, we need projects that help us better understand the true population status of Blackpoll Warbler and its winter habitat requirements.

State of Mountain Birds