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

Yellow-billed Cuckoo Population Trend in Maine

All statesGeneralists

Yellow-billed Cuckoo in Maine has surged: up 96% on the route-weighted index since 1978.

+96%Since 1978TrendPercent 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 →
18Routes 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 →
27YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Yellow-billed Cuckoo Trends in MaineNotable 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 →

Yellow-billed Cuckoo has surged in Maine: up 96% on the route-weighted index since 1978.

Yellow-billed Cuckoo Population Forecast in Maine

If the recent trend holds, Yellow-billed Cuckoo in Maine is projected to fall about 55% by 2027 — from 0.14 in 2022 to a central estimate of 0.06 (95% range 0.00–0.23). A 5-year backtest shows a typical error of ±47.9%, with 100% of held-out values landing inside the 95% band.

-55%Change by 2027TrendPercent 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 →
0.06Projected 2027 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.2395% 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 →
±47.9%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, Yellow-billed Cuckoo in Maine is projected to fall about 55% by 2027 — from 0.14 in 2022 to a central estimate of 0.06 (95% range 0.00–0.23). A 5-year backtest shows a typical error of ±47.9%, with 100% of held-out values landing inside the 95% band.19682027
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 →
20230.070.000.23
20240.070.000.23
20250.070.000.23
20260.070.000.23
20270.060.000.23

Yellow-billed Cuckoo Survey Routes in Maine

Routes recording Yellow-billed Cuckoo in Maine.
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 →
Turner719971997
Hartford320222012
Eastbrook220191980
Northfield219811979
Cape Neddick119811981
Westbrook120141977
Biddeford119901980
Kittery Pt119681968
Greenville119971997
Benedicta119791979
South Arm120142014
Bowdoin Ctr120111980
East Troy120192019
Rome119961996
Searsport120112011
Hancock119991980
Brownfield 2120152013
Carrying Pl120032003

Yellow-billed Cuckoo Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawest-virginiawisconsinwyoming

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