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

Northern Mockingbird Population Trend in Delaware

All statesGeneralists

Northern Mockingbird in Delaware has held roughly steady: down 3% on the route-weighted index since 1968.

-3%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 Northern Mockingbird 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 →

No notable trend signals for Northern Mockingbird in Delaware. See the full index history below.

Northern Mockingbird Population Forecast in Delaware

If the recent trend holds, Northern Mockingbird in Delaware is projected to stay roughly flat through 2029, near 28 (95% range 20–37). A 5-year backtest shows a typical error of ±36.3%, with 40% of held-out values landing inside the 95% band.

+6%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 →
28Projected 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 →
20–3795% 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 →
±36.3%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, Northern Mockingbird in Delaware is projected to stay roughly flat through 2029, near 28 (95% range 20–37). A 5-year backtest shows a typical error of ±36.3%, with 40% 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 →
2025281936
2026281936
2027282036
2028282037
2029282037

Northern Mockingbird Survey Routes in Delaware

Routes recording Northern Mockingbird 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 →
Holleyville3920041966
Holleyville 23620242006
Harrington3120241966
Lowes Xrds3019911966
Georgetown2720221992
Pepperbox 22620242017
Milton2520161966
Pepperbox2520161998
Milton 22420172017
Blackbird2320241994
Frederica1920141966
Frankford1820121966
Millsboro1720242017
Wilmington1420141966
Mt Pleasant1220191966
Bethany Bch1119901966
Dover919871966

Northern Mockingbird Population Trend in Other States

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

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