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

Yellow-billed Cuckoo Population Trend in Pennsylvania

All statesGeneralists

Yellow-billed Cuckoo in Pennsylvania has increased: up 49% on the route-weighted index since 1968.

+49%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 →
134Routes 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 Yellow-billed Cuckoo Trends in PennsylvaniaNotable 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 Yellow-billed Cuckoo in Pennsylvania. See the full index history below.

Yellow-billed Cuckoo Population Forecast in Pennsylvania

If the recent trend holds, Yellow-billed Cuckoo in Pennsylvania is projected to rise about 99% by 2029 — from 0.79 in 2024 to a central estimate of 1.6 (95% range 0.23–2.9). A 5-year backtest shows a typical error of ±53.7%, with 100% of held-out values landing inside the 95% band.

+99%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 →
1.6Projected 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 →
0.23–2.995% 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 →
±53.7%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 Pennsylvania is projected to rise about 99% by 2029 — from 0.79 in 2024 to a central estimate of 1.6 (95% range 0.23–2.9). A 5-year backtest shows a typical error of ±53.7%, with 100% 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 →
20251.60.232.9
20261.60.232.9
20271.60.232.9
20281.60.232.9
20291.60.232.9

Yellow-billed Cuckoo Survey Routes in Pennsylvania

Routes recording Yellow-billed Cuckoo in Pennsylvania.
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 →
Sproul Sf-B1820232003
Rosecrans1720231969
Mawr Glen1220241983
Big Flat1019811966
Jeannette1020221981
Bendersville1020241990
Roulette720211973
Wakena720191969
Ryde720051968
Peru Mills720241966
Aspers719831970
Wyalusing720221988
Bald Eagle620231971
Waterstreet620231968
Stoneybreak620241992
Ramsey520231969
Little Marsh520231985
Starlight519831971
Pine Gr Mill520231967
Ltl Pine Cr520241990
Tussey Mtn.520241993
Slippery Rk419911990
Pottersdale420241969
Odin420171973
Sardis419731970

Yellow-billed Cuckoo Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawest-virginiawisconsinwyoming

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