Bird Declines are Reaching a Tipping Point
As Road to Recovery develops an approach to reverse staggering continental avian declines, we start 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 that broader ecosystem or habitat initiatives benefit multiple species without the most urgently declining species slipping through the cracks.
Scientists for the Road to Recovery initiative have identified 104 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 toward sustainable recovery.
To assess Tipping Point species vulnerability and urgency, we relied first 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. 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 population size and trend 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 Nonbreeding 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). Species that meet a threshold of CCS > 13 are considered to be highly vulnerable and are placed on the ACAD Watch List.
Population Decline: Based on the latest long-term population trend data for U.S./Canada species, we identified those 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 and include many Watch List species. This analysis mirrors the survey data used to assess population change for 529 species in Rosenberg et al. (2019), updated with data through 2019 (J. Sauer) and including a complete re-analysis of shorebird trend data by Paul Smith (Smith et al. In press).
Urgency: To assess urgency, we examined the most recent population trajectories for each species based on the most recent analysis of BBS and other survey data (updated through 2019). 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 with very large long-term population loss ( ≥ 75%), resulting in perilously low population size. Continued or accelerated recent declines indicate a loss of one-third or more of the population over the past 3 generations. This alert level also includes species with very small global population (PS = 5) and either ≥ 30% recent population loss or expert-assigned PT = 5 or 4 (poorly monitored, see below).
Orange Alert: Species with large long-term population loss ( > 50%) and with continued or accelerated recent declines resulting in a loss ≥ 10% over the most recent 3 generations; OR species with small global populations (PS = 4) that exhibit either steep recent declines ( ≥ 30% population loss) or expert-assigned PT = 4 or 5 (poorly monitored, see below).
Yellow Alert: An additional set of species have experienced large long-term population loss ( ≥ 50%), but now show stable ( < ± 10%) 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. We highlight these species as “Yellow-Alert.”
Presumed Urgency—Poorly Monitored: For many species included in the ACAD Watch List based on a combination of small global population or distribution and high threats (TB or TN = 4, 5), we lack long-term monitoring data to compare long-term and recent trends. For these poorly monitored species, we can still assess urgency based on ACAD scores; we use a combination of small population size (PS = 4, 5) and expert-assigned PT scores (5, 4, or 3) to assign each to either Red-, Orange-, or Yellow-Alert categories; they are denoted with an asterisk in the list below.
Summary of Urgency Alert Levels and Definitions
Species with trend data
Species with or without long-term trend data
Long-term population loss ≥ 75% AND recent (3-generation) decline ≥ 30%
Population very small (PS = 5) AND decline either known to be ≥ 30% recent (3-generation) OR suspected to be moderate to large (PT= 4 or 5)
Long-term population loss ≥ 50% AND recent (3-generation) decline ≥ 10%
Population small (PS = 4) AND decline either known to be ≥ 30% recent (3-generation); OR suspected to be moderate to large (PT= 4 or 5); OR very small population (PS = 5) and unknown trend (PT = 3)
Long-term population loss ≥ 50% BUT short-term (3-generation) decline < 10%, or increasing
Population small (PS = 4) AND population trend uncertain
Tipping Point Species List
Scientists for the Road to Recovery initiative have identified 104 Tipping Point Species in need of focused and immediate scientific action to pinpoint causes of declines and to support practitioners dedicated to recovering their populations. Note that some of these species are already listed as Endangered, Threatened, or Special Concern under federal legislation in the U.S. (Endangered Species Act [ESA]) or Canada (Species at Risk Act [SARA]). An asterisk denotes Presumed Urgency—Poorly Monitored species.
Florida Scrub-Jay* (ESA)
Gunnison Sage-Grouse* (ESA)
Ivory Gull* (SARA)
King Rail (SARA)
Least Tern (ESA)
Lesser Prairie-Chicken* (ESA)
Mountain Plover (SARA)
Red Knot (ESA, SARA)
Spotted Owl* (ESA, SARA)
Sprague’s Pipit (SARA)
Bermuda Petrel* (ESA)
Bicknell’s Thrush* (SARA)
Buff-breasted Sandpiper (SARA)
Chimney Swift (SARA)
Chestnut-collared Longspur (SARA)
Great Black-backed Gull
Greater Prairie-Chicken (SARA)
Greater Sage-Grouse (SARA)
Harris’s Sparrow (SARA)
Henslow’s Sparrow (SARA)
Marbled Murrelet (ESA, SARA)
Piping Plover (ESA, SARA)
Pink-footed Shearwater* (SARA)
Ridgway’s Rail* (ESA)
Roseate Tern* (ESA)
Ross’s Gull* (SARA)
Spectacled Eider* (ESA)
Steller’s Eider* (ESA)
Yellow Rail* (SARA)
Baird’s Sparrow (SARA)
Black Swift (SARA)
Black-footed Albatross* (SARA)
Canada Warbler (SARA)
Cerulean Warbler (SARA)
Eastern Whip-poor-will (SARA)
Evening Grosbeak (SARA)
Golden-winged Warbler (SARA)
Olive-sided Flycatcher (SARA)
Thick-billed Longspur (SARA)
Wood Thrush (SARA)
Pilot Species Working Groups
With generous support from the Knobloch Family Foundation, Road to Recovery is able to begin supporting the pilot projects focused on the recovery of four species, three of which are Tipping Point Species. The purpose of these projects is to provide a proof of concept for advancing both biological and social science targeted at identifying and addressing causes of species declines.