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

Common Yellowthroat Population Trend in Delaware

All statesForest birds

Common Yellowthroat in Delaware has risen sharply: up 72% on the route-weighted index since 1968.

+72%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 →
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 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 risen sharply in Delaware: up 72% 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 36% by 2029 — from 20 in 2024 to a central estimate of 13 (95% range 4.4–21). A 5-year backtest shows a typical error of ±34.9%, with 60% of held-out values landing inside the 95% band.

-36%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 →
13Projected 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 →
4.4–2195% 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 →
±34.9%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, Common Yellowthroat in Delaware is projected to fall about 36% by 2029 — from 20 in 2024 to a central estimate of 13 (95% range 4.4–21). A 5-year backtest shows a typical error of ±34.9%, 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 →
2025134.421
2026134.421
2027134.421
2028134.421
2029134.421

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 →
Blackbird5220241994
Harrington2220241966
Millsboro1920242017
Lowes Xrds1619911966
Milton 21620172017
Dover919871966
Bethany Bch919901966
Frankford820121966
Pepperbox820161998
Holleyville520041966
Milton520161966
Georgetown520221992
Pepperbox 2520242017
Frederica320141966
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 2026-05-22.