When Road to Recovery (R2R) initiated its approach to reverse staggering continental avian declines, we began by asking “Which species do we need to work on first?” to identify specific limiting factors and causes of declines and to support the teams of scientists and practitioners dedicated to recovering their populations. Identifying causes of declines species-by-species can pinpoint different threats and limitations for species living in the same habitats throughout their annual cycles. Incorporating species-specific knowledge ensures broader ecosystem or habitat initiatives benefit multiple species without the most urgently declining species slipping through the cracks. 

Scientists at R2R have identified 112 Tipping Point bird species that require immediate, focused scientific action to pinpoint causes of declines and develop strategies for recovery. R2R’s goal is to guide and support teams of practitioners (species working groups or recovery teams) in the U.S. and Canada dedicated to recovering bird populations. R2R integrates biological and social science to co-produce solutions that advance species towards sustainable recovery.

To assess Tipping Point species vulnerability and urgency, we relied on data already available in the Avian Conservation Assessment Database (ACAD)—a database maintained by Partners in Flight (PIF) and housed at Bird Conservancy of the Rockies (PIF 2024). The recent global ACAD update (December 2023) incorporated data used by R2R to assess urgency, resulting in a single conservation assessment for both Watch List and Tipping Point species. All Tipping Point species exhibit high vulnerability to extinction and worrisome population declines as described below. We further identify three levels of alert—based on the severity of both long-term and short-term declines, or for species lacking monitoring data, a combination of expert-assigned vulnerability scores—that signify the degree of urgency in addressing these declines: Red-, Orange-, and Yellow-Alert species.

High Vulnerability to Extinction: Vulnerability in the ACAD is assessed by carefully scoring a series of independent factors (Population Size, Breeding and Non-breeding Distribution, Threats, and Trend) that are combined into a single Combined Conservation Score (CCS) that ranges from 4 to 20 (see the ACAD Handbook for a thorough description; Panjabi et al. 2024). Species that meet a threshold of CCS > 13 are considered to be highly vulnerable and are placed on the ACAD Watch List. Species with high scores across multiple factors (CCS > 16) are on the Red Watch List.

Population Decline: Based on the latest long-term population trend data for U.S./Canada species, we identified those Watch List species that are estimated to have lost 50% or more of their total adult breeding population since 1970. These species are assigned a Population Trend (PT) score = 5 in the ACAD. This analysis mirrors the survey data used to assess population change for 529 species in Rosenberg et al. (2019), updated with data through 2021 and including a complete re-analysis of shorebird trend data by Paul Smith (Smith et al. 2023).

Urgency: To assess urgency, we examined population trajectories for each species based on the most recent analysis of BBS and other survey data (updated through 2021). By comparing long-term trends (back to 1970 for most species; to 1980 for shorebirds) with the most recent population trajectories (defining “recent” as a 3-generation time frame), we identified species in three urgency categories:

Red Alert: Species that qualify for ACAD Red Watch List based on multiple high vulnerability scores, usually including perilously low population size and steeply declining or unknown population trend.

Orange Alert: Corresponds with ACAD Orange Watch List; species with very large long-term population loss (> 75%); OR species with large long-term loss (>50%) and with continued or accelerated recent declines resulting in a loss ≥ 30% over the most recent 3 generations or a half-life < 30 years. Also includes a few conservation-reliant species that are beginning to recover but still require urgent attention.

Yellow Alert: Corresponds with a subset of ACAD Yellow Watch List species that have experienced large long-term population loss ( ≥ 50%), but now show relatively stable or even increasing populations over the most recent 3-generation period. These species may be responding to current conservation efforts but still require recovery to healthier population levels.

Poorly Monitored Species: For many species included in the ACAD Watch List based on a combination of small global population or distribution and high threats, we lack long-term monitoring data to compare long-term and recent trends, yet we can assess their urgency based on ACAD scores. For these poorly monitored species, we use a combination of expert-assigned scores to assign each to either Red-, Orange-, or Yellow-Alert categories; they are denoted with an asterisk in the list below.