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

Common Yellowthroat Population Trend in Delaware

All statesForest birds

Common Yellowthroat in Delaware has surged: up 77% on the route-weighted index since 1968.

+77%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 →
17Routes 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 Common Yellowthroat Trends in DelawareNotable 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 →

Common Yellowthroat has surged in Delaware: up 76% on the route-weighted index since 1968.

Common Yellowthroat Population Forecast in Delaware

If the recent trend holds, Common Yellowthroat in Delaware is projected to fall about 23% by 2030 — from 17 in 2025 to a central estimate of 13 (95% range 4.7–22). A 5-year backtest shows a typical error of ±38.8%, with 60% of held-out values landing inside the 95% band.

-23%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 →
13Projected 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 →
4.7–2295% 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 →
±38.8%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, Common Yellowthroat in Delaware is projected to fall about 23% by 2030 — from 17 in 2025 to a central estimate of 13 (95% range 4.7–22). A 5-year backtest shows a typical error of ±38.8%, 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 →
2026134.722
2027134.722
2028134.722
2029134.722
2030134.722

Common Yellowthroat Survey Routes in Delaware

Routes recording Common Yellowthroat in Delaware.
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 →
Blackbird4220251994
Milton 21920252017
Lowes Xrds1619911966
Harrington1520251966
Millsboro1520252017
Dover919871966
Bethany Bch919901966
Frankford820121966
Pepperbox820161998
Pepperbox 2820252017
Holleyville520041966
Milton520161966
Georgetown520221992
Frederica320251966
Holleyville 2320242006
Mt Pleasant120191966
Wilmington120141966

Common Yellowthroat Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutfloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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