The Road to Recovery Species Lists
R2R: Prioritizing Species for Recovery
Species on the Brink of Endangerment
In developing the Road to Recovery approach to reversing avian declines, we start by asking “Which species do we need to work on first?” in terms of identifying specific limiting factors and causes of declines and supporting the teams of scientists and practitioners dedicated to recovering their populations. Which species are most likely to slip into ESA T&E status or head toward extinction or extirpation in the near future if no conservation action is taken and for which it is imperative that we conduct the science needed to identify the specific causes of decline—and develop proactive strategies for species recovery before listing is imminent?
To address this question, we relied first on data already available in the Avian Conservation Assessment Database (ACAD)—a database created and maintained by Partners in Flight (PIF) and housed at Bird Conservancy of the Rockies. We identified a group of 62 species that exhibit a combination of high vulnerability to extinction, steep population decline, and high urgency, as described below. We note that long-term monitoring data provided by the North American Breeding Bird Survey, as well as ancillary data from other surveys such as the Christmas bird Count and International Shorebird Survey, are foundational to our ability to assess the conservation status of species and identify species on the brink of endangerment.
High Vulnerability to Extinction (High Concern): 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. Species with CCS ≥ 16 show very high vulnerability across multiple factors and constitute the Red Watch List.
Steep Population Decline: Based on the latest long-term population trend data for 529 US/Canada species (Rosenberg et al. 2019 in Science), we identified those species that are estimated to have lost 50% or more of their total adult breeding population since 1970. This group of species are assigned a Population Trend (PT) score = 5 in the ACAD and include many Watch List species and also a set of Common Species in Steep Decline that do not meet Watch List CCS criteria. Trend data for most species have been updated with data through 2019.
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 by John R. Sauer (US Geological Survey). This analysis mirrors the survey data used to assess trends for 529 species in Rosenberg et al. (2019) and have been updated for most species with data through 2019. Notably this analysis includes a complete re-analysis of shorebird trend data by Paul Smith and Adam Smith (unpublished, presented at AOS August 2021). By comparing long-term trends (back to 1970 for most species; to 1980 for shorebirds) with the most recent population trajectories (using a 3-generation period to define “recent” period), we identified species in three urgency categories, as follows:
Very High Urgency—species with very large long-term population loss (>75%) and with continued or accelerated declines in the recent period
High Urgency—species with large long-term population loss (>50%) and with continued or accelerated recent declines
Moderate Urgency—species with large long-term population loss (>50%) but showing smaller recent declines or a leveling off or increase in their recent population trend.
This process resulted in 39 species with Very High or High Urgency and an additional 23 species of Moderate Urgency. Species on the Red Watch List were considered to have higher urgency than other species exhibiting similar trends. Note that all Very High and High Urgency species exhibit a “half-life” < 50 years when projecting forward the most recent (3-generation) trend. This half-life metric was first developed by Stanton et al. (2016) and applied to landbirds in the 2016 PIF Landbird Conservation Plan.
However, there are a number of additional species with small populations and high threats (Red Watch List) for which we lack the long-term monitoring data needed to quantitatively assess the magnitude of decline or the urgency. Thus, we designate an additional category:
Presumed High Urgency/Data Deficient—Poorly-monitored species that are believed to be declining and have been assigned PT scores of 5 or 4 in the ACAD via expert opinion; for some of these, the population trend is completely unknown. This additional set of species are defined by a combination of small population size (PS = 4,5) and high threats (TB or TN = 4,5) and have expert-assigned PT scores of 5,4, or 3.
This set of Data Deficient species adds an additional 29 species to the R2R Species on the Brink List for a total of 91 species. These species, none of which are currently listed as Endangered or Threatened in the U.S., constitute what we are calling the Road to Recovery Species on the Brink List. These are species most likely to slip into ESA T&E status or head toward extinction or extirpation in the near future if no conservation action is taken and for which it is imperative that we conduct the science needed to identify and address the specific causes of decline.
Sources Cited:
Partners in Flight. 2020a. Avian Conservation Assessment Database, version 2020. Available at http://pif.birdconservancy.org/ACAD.
Rosenberg, K.V., A.M. Dokter, P.J. Blancher, J.R. Sauer, A.C. Smith, P.A. Smith, J.C. Stanton, A. Panjabi, L. Helft, M. Parr, and P.P. Mara. 2019. Decline of the North American Avifauna. Science 10.1126/science.aaw1313.
Stanton J.C., B.X. Semmens, P.C. McKann, T. Will, and W.E. Thogmartin. 2016. Flexible risk metrics for identifying and monitoring conservation-priority species. Ecological Indicators 61, Part 2:683–692.
R2R Species on the Brink List (6/9/22)
Very High Urgency (very large population loss, continued or accelerated decline):
- King Eider
- Mottled Duck
- Allen’s Hummingbird
- King Rail
- Mountain Plover
- American Golden-Plover
- Ruddy Turnstone
- Red Knot
- Wandering Tattler
- Short-billed Dowitcher
- Lesser Yellowlegs
- Hudsonian Godwit
- Whimbrel
- Least Tern
- Red-faced Cormorant
- Yellow-billed Magpie
- Chestnut-collared Longspur
- Sprague’s Pipit
High Urgency (large population loss, continued or accelerated decline):
- Black Scoter
- Greater Sage-Grouse
- Rufous Hummingbird
- Chimney Swift
- Buff-breasted Sandpiper
- Pectoral Sandpiper
- Semipalmated Sandpiper
- Stilt Sandpiper
- Great Black-backed Gull
- Yellow-billed Loon
- Pinyon Jay
- Bendire’s Thrasher
- LeConte’s Thrasher
- Black-chinned Sparrow
- Bachman’s Sparrow
- Harris’s Sparrow
- LeConte’s Sparrow
- Saltmarsh Sparrow
- Bobolink
- Golden-winged Warbler
- Evening Grosbeak
Moderate Urgency (large population loss, smaller recent decline or leveling off):
- Black-billed Cuckoo
- Eastern Whip-poor-will
- Black Swift
- Wilson’s Plover
- Rock Sandpiper
- Surfbird
- Long-billed Dowitcher
- Black Skimmer
- Clark’s Grebe
- Western Grebe
- Snowy Owl
- Red-headed Woodpecker
- Olive-sided Flycatcher
- Thick-billed Longspur
- Wood Thrush
- Baird’s Sparrow
- Henslow’s Sparrow
- Seaside Sparrow
- Cerulean Warbler
- Grace’s Warbler
- Prairie Warbler
- Canada Warbler
- Mourning Warbler
Data Deficient (Small Population, high threats, insufficient monitoring data):
- Lesser Prairie-Chicken
- Yellow Rail
- Black Rail
- Bristle-thighed Curlew
- Kittlitz’s Murrelet
- Scripps’s Murrelet
- Guadalupe Murrelet
- Craveri’s Murrelet
- Whiskered Auklet
- Red-legged Kittiwake
- Ivory Gull
- Heermann’s Gull
- Elegant Tern
- Black-footed Albatross
- Short-tailed Albatross
- Townsend’s Storm-Petrel
- Ashy Storm-Petrel
- Band-rumped Storm-Petrel
- Murphy’s Petrel
- Black-capped Petrel
- Fea’s Petrel
- Parkinson’s Petrel
- Black-vented Shearwater
- Audubon’s Shearwater
- Bicknell’s Thrush
- Black Rosy-Finch
- Brown-capped Rosy-Finch
- Cassia Crossbill
- Tricolored Blackbird
