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

Yellow-billed Cuckoo Population Trend in Delaware

All statesGeneralists

Yellow-billed Cuckoo in Delaware has surged: up 152% on the route-weighted index since 1968.

+152%Since 1968
17Routes In State
58Years

Notable Yellow-billed Cuckoo Trends in Delaware

long arc increasecomputed index

Yellow-billed Cuckoo has surged in Delaware: up 152% on the route-weighted index since 1968.

Yellow-billed Cuckoo Population Forecast in Delaware

If the recent trend holds, Yellow-billed Cuckoo in Delaware is projected to fall about 45% by 2029 — from 5.4 in 2024 to a central estimate of 2.9 (95% range 0.00–7.2). A 5-year backtest shows a typical error of ±66.9%, with 40% of held-out values landing inside the 95% band.

-45%Change by 2029
2.9Projected 2029 index
0.00–7.295% range
±66.9%Backtest error
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 index95% low95% high
20252.90.007.2
20262.90.007.2
20272.90.007.2
20282.90.007.2
20292.90.007.2

Yellow-billed Cuckoo Survey Routes in Delaware

Routes recording Yellow-billed Cuckoo in Delaware.
Pepperbox 21320242017
Blackbird1120241994
Milton 21120172017
Lowes Xrds919911966
Holleyville 2920192006
Holleyville720041966
Harrington420221966
Georgetown420221992
Millsboro320242017
Frankford220121966
Milton220141967
Mt Pleasant120051966
Wilmington120111966
Frederica120141966
Dover119861967
Bethany Bch119901966
Pepperbox120161998

Yellow-billed Cuckoo Population Trend in Other States

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

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