BirdAnalyst
Species · Illinois · BBS 2026 Release · 1966–2025

Eastern Phoebe Population Trend in Illinois

All statesAerial insectivores

Eastern Phoebe in Illinois has surged: up 466% on the route-weighted index since 1968.

+466%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 →
105Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
59YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Eastern Phoebe Trends in IllinoisNotable 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 →

Eastern Phoebe has surged in Illinois: up 466% on the route-weighted index since 1968.

Eastern Phoebe Population Forecast in Illinois

If the recent trend holds, Eastern Phoebe in Illinois is projected to stay roughly flat through 2030, near 2.8 (95% range 1.9–3.6). A 5-year backtest shows a typical error of ±35.9%, with 60% of held-out values landing inside the 95% band.

-5%Change by 2030TrendPercent 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 →
2.8Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
1.9–3.695% 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 →
±35.9%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, Eastern Phoebe in Illinois is projected to stay roughly flat through 2030, near 2.8 (95% range 1.9–3.6). A 5-year backtest shows a typical error of ±35.9%, with 60% of held-out values landing inside the 95% band.19662030
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 →
20262.61.73.5
20272.61.83.5
20282.71.83.6
20292.71.83.6
20302.81.93.6

Eastern Phoebe Survey Routes in Illinois

Routes recording Eastern Phoebe in Illinois.
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 →
Beaverdam Lk1120231970
Robinson1020231975
Bradbury920251970
Eldred920251993
York920251993
Camp Point820251994
Marshall720252010
Gulfport620251971
Terre Haute620251966
Fairbury620251976
Humphrey620251974
Bremen620251970
Belknap620251970
Delwood620251970
Eubanks620252001
Deer Creek520241968
Concord520251968
Birds520241978
Duncan Mills520251993
Dudleyville520252001
Bartonville420251973
Melrose419991973
Belleview420251966
Janesville420251978
Martinsville420251970

Eastern Phoebe Population Trend in Other States

alabamaarkansascoloradoconnecticutdelawarefloridageorgiaindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawest-virginiawisconsinwyoming

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.