BirdAnalyst
Species · Illinois · BBS 2025 Release · 1966–2024

Eastern Phoebe Population Trend in Illinois

All statesAerial insectivores

Eastern Phoebe in Illinois has surged: up 378% on the route-weighted index since 1968.

+378%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 →
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 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 378% 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 2029, near 2.7 (95% range 1.8–3.6). A 5-year backtest shows a typical error of ±36.3%, with 60% of held-out values landing inside the 95% band.

+3%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 →
2.7Projected 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 →
1.8–3.695% 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 →
±36.3%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, Eastern Phoebe in Illinois is projected to stay roughly flat through 2029, near 2.7 (95% range 1.8–3.6). A 5-year backtest shows a typical error of ±36.3%, with 60% 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 →
20252.51.63.4
20262.61.73.4
20272.61.73.5
20282.61.83.5
20292.71.83.6

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
Royalton920242001
Belleview820241966
Mt Vernon820241971
Belknap820241970
York820241993
Terre Haute720241966
Bradbury620241970
Bremen620241970
Deer Creek520241968
Martinsville520241970
Columbia520241967
Birds520241978
Clayton520242001
Mill Creek420231968
Chandlervill420241972
Bartonville420241973
Pontiac420241991
Melrose419991973
Athensville420241972
Humphrey420241974
Janesville420241978
Sandusky420231993
Eubanks420242001

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 2026-05-22.