BirdAnalyst
Species · BCR 28 · BBS 2025 Release · 1966–2024

Blue-gray Gnatcatcher In Appalachian Mountains

All regionsAppalachian MountainsForest birds

Blue-gray Gnatcatcher in Appalachian Mountains has surged: up 78% on the route-weighted index since 1968.

+78%Since 1968TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
374Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
58YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable SignalsNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

long arc increasecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Blue-gray Gnatcatcher has surged in Appalachian Mountains: up 78% on the route-weighted index since 1968.

Blue-gray Gnatcatcher In Appalachian Mountains Population Forecast

If the recent trend holds, Blue-gray Gnatcatcher in Appalachian Mountains is projected to rise about 27% by 2029 — from 3.3 in 2024 to a central estimate of 4.2 (95% range 2.7–5.7). A 5-year backtest shows a typical error of ±33.9%, with 80% of held-out values landing inside the 95% band.

+27%Change by 2029TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
4.2Projected 2029 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
2.7–5.795% range95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
±33.9%Backtest errorBacktest errorTypical error when we hold out the most recent years, forecast them, and compare to what actually happened. Lower means a more trustworthy projection.Full methodology →
If the recent trend holds, Blue-gray Gnatcatcher in Appalachian Mountains is projected to rise about 27% by 2029 — from 3.3 in 2024 to a central estimate of 4.2 (95% range 2.7–5.7). A 5-year backtest shows a typical error of ±33.9%, with 80% of held-out values landing inside the 95% band.19662029
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →95% low95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →95% high95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
20254.12.65.6
20264.12.65.6
20274.22.75.7
20284.22.75.7
20294.22.75.7

Routes In Appalachian Mountains

Routes recording Blue-gray Gnatcatcher in Appalachian Mountains.
Recent countThe raw number of individuals recorded on this route in its most recent survey year. A single-route tally, not a trend.Full methodology →
Cumberlnd GpKENTUCKY872018
StevensonALABAMA342024
Borden Springs 2ALABAMA302024
Mt OliveALABAMA262024
StaffordsvilKENTUCKY261997
Amos MillGEORGIA252022
DellOHIO252019
Corryton RdTENNESSEE232019
RiversideALABAMA222013
OldtownMARYLAND212024
WelchWEST-VIRGINIA212023
Zaleski S.F.OHIO202024
LinwoodGEORGIA182023
BramwellWEST-VIRGINIA182023
HubbardstownWEST-VIRGINIA182023
Beattyville 2KENTUCKY172024
PaintsvilleKENTUCKY171995
FontanaNORTH-CAROLINA162024
Smokey JctTENNESSEE162022
LovellTENNESSEE162019
WallandTENNESSEE161989
Smyer LakeALABAMA152024
Borden SprngALABAMA151998
WilliamsportMARYLAND152024
CovingtonVIRGINIA152024

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.