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Species · BCR 12 · BBS 2025 Release · 1966–2024

Blue-gray Gnatcatcher In Boreal Hardwood Transition

All regionsBoreal Hardwood TransitionForest birds

Blue-gray Gnatcatcher in Boreal Hardwood Transition has surged: up 102% on the route-weighted index since 1989.

+102%Since 1989TrendPercent 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 →
17Routes 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 →
29YearsYears 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 →

No notable trend signals for Blue-gray Gnatcatcher in Boreal Hardwood Transition. See the full index history below.

Blue-gray Gnatcatcher In Boreal Hardwood Transition Population Forecast

If the recent trend holds, Blue-gray Gnatcatcher in Boreal Hardwood Transition is projected to fall about 25% by 2029 — from 0.07 in 2024 to a central estimate of 0.05 (95% range 0.00–0.10). A 5-year backtest shows a typical error of ±111%, with 100% of held-out values landing inside the 95% band.

-25%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 →
0.05Projected 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 →
0.00–0.1095% 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 →
±111%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 Boreal Hardwood Transition is projected to fall about 25% by 2029 — from 0.07 in 2024 to a central estimate of 0.05 (95% range 0.00–0.10). A 5-year backtest shows a typical error of ±111%, with 100% of held-out values landing inside the 95% band.19772029
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 →
20250.050.000.09
20260.050.000.09
20270.050.000.10
20280.050.000.10
20290.050.000.10

Routes In Boreal Hardwood Transition

Routes recording Blue-gray Gnatcatcher in Boreal Hardwood Transition.
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 →
Skegemog PtMICHIGAN22024
Bear LakeMICHIGAN11993
GilchristMICHIGAN11999
SkeelsMICHIGAN12004
CathroMICHIGAN11986
HarriettaMICHIGAN12024
Wigwam BayMINNESOTA12015
Mille LacsMINNESOTA12008
BrainerdMINNESOTA12002
Union TwpWISCONSIN12024
CouderayWISCONSIN12011
PhillipsWISCONSIN12002
AmbergWISCONSIN12022
WausaukeeWISCONSIN12009
Washington IWISCONSIN12021
BashawWISCONSIN12024
RhinelanderWISCONSIN12010

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