BirdAnalyst
Species · BCR 23 · BBS 2025 Release · 1966–2024

Blue-gray Gnatcatcher In Prairie Hardwood Transition

All regionsPrairie Hardwood TransitionForest birds

Blue-gray Gnatcatcher in Prairie Hardwood Transition has surged: up 24× on the route-weighted index since 1969.

24×Since 1969TrendPercent 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 →
136Routes 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 →
57YearsYears 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 Prairie Hardwood Transition: up 24× on the route-weighted index since 1969.

Blue-gray Gnatcatcher In Prairie Hardwood Transition Population Forecast

If the recent trend holds, Blue-gray Gnatcatcher in Prairie Hardwood Transition is projected to rise about 56% by 2029 — from 0.74 in 2024 to a central estimate of 1.2 (95% range 0.80–1.5). A 5-year backtest shows a typical error of ±69.8%, with 0% of held-out values landing inside the 95% band.

+56%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 →
1.2Projected 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 →
0.80–1.595% 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 →
±69.8%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 Prairie Hardwood Transition is projected to rise about 56% by 2029 — from 0.74 in 2024 to a central estimate of 1.2 (95% range 0.80–1.5). A 5-year backtest shows a typical error of ±69.8%, with 0% 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 →
20251.10.731.4
20261.10.751.5
20271.10.771.5
20281.10.791.5
20291.20.801.5

Routes In Prairie Hardwood Transition

Routes recording Blue-gray Gnatcatcher in Prairie 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 →
WhitewaterMINNESOTA122000
AlmenaMICHIGAN92015
New BuffaloMICHIGAN82014
BravoMICHIGAN72023
Allegan WmaMICHIGAN52013
North BranchMICHIGAN41996
Barry S.G.A.MICHIGAN42012
N FreedomWISCONSIN42024
HebronWISCONSIN42024
HighlandWISCONSIN42024
Mukwonago 2WISCONSIN42024
PackertownINDIANA32004
MontereyMICHIGAN32024
MottvilleMICHIGAN32024
CohoctahMICHIGAN32024
Belding 2MICHIGAN32024
RochesterMICHIGAN32024
Hamburg 2MICHIGAN32024
MillvilleMINNESOTA32016
Caledonia 2MINNESOTA32024
HudsonWISCONSIN32016
GilmantonWISCONSIN32024
TrempealeauWISCONSIN32010
CadottWISCONSIN32024
ClintonvilleWISCONSIN32013

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