BirdAnalyst
Species · BCR 24 · BBS 2025 Release · 1966–2024

Blue-gray Gnatcatcher In Central Hardwoods

All regionsCentral HardwoodsForest birds

Blue-gray Gnatcatcher in Central Hardwoods has surged: up 123% on the route-weighted index since 1968.

+123%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 →
165Routes 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 Central Hardwoods: up 123% on the route-weighted index since 1968.

Blue-gray Gnatcatcher In Central Hardwoods Population Forecast

If the recent trend holds, Blue-gray Gnatcatcher in Central Hardwoods is projected to rise about 57% by 2029 — from 7.5 in 2024 to a central estimate of 12 (95% range 9.2–14). A 5-year backtest shows a typical error of ±43.3%, with 20% of held-out values landing inside the 95% band.

+57%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 →
12Projected 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 →
9.2–1495% 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 →
±43.3%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 Central Hardwoods is projected to rise about 57% by 2029 — from 7.5 in 2024 to a central estimate of 12 (95% range 9.2–14). A 5-year backtest shows a typical error of ±43.3%, with 20% 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 →
2025118.614
2026118.814
2027128.914
2028129.114
2029129.214

Routes In Central Hardwoods

Routes recording Blue-gray Gnatcatcher in Central Hardwoods.
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 →
ClementineMISSOURI452002
Clementine 2MISSOURI432007
Levee 2KENTUCKY412019
RomeOHIO342024
Trace CollinwoodTENNESSEE282018
CascadeMISSOURI272024
BremenILLINOIS252024
MincyMISSOURI252024
TrianaALABAMA242012
ZionARKANSAS242024
Indian Mound 2TENNESSEE242023
Rueter 2MISSOURI232024
Trace LewisTENNESSEE232017
Mammoth CaveKENTUCKY212014
BlandMISSOURI212024
RoyaltonILLINOIS202024
PalaceMISSOURI202024
Beaverdam LkILLINOIS192023
Osage BeachMISSOURI192024
EugeneMISSOURI182024
CampbellsvilleTENNESSEE182017
Ravenden SpringsARKANSAS172015
LincolnMISSOURI172024
Doe RunMISSOURI172024
Cave In RockILLINOIS162024

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