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

Ruby-throated Hummingbird Population Trend in Delaware

All statesGeneralists

Ruby-throated Hummingbird in Delaware has surged: up 188% on the route-weighted index since 1968.

+188%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 →
51YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Ruby-throated Hummingbird 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 →

Ruby-throated Hummingbird has surged in Delaware: up 188% on the route-weighted index since 1968.

Ruby-throated Hummingbird Population Forecast in Delaware

If the recent trend holds, Ruby-throated Hummingbird in Delaware is projected to rise about 25% by 2029 — from 0.80 in 2024 to a central estimate of 1.00 (95% range 0.49–1.5). A 5-year backtest shows a typical error of ±17.6%, with 100% of held-out values landing inside the 95% band.

+25%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 →
1.00Projected 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 →
0.49–1.595% 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 →
±17.6%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, Ruby-throated Hummingbird in Delaware is projected to rise about 25% by 2029 — from 0.80 in 2024 to a central estimate of 1.00 (95% range 0.49–1.5). A 5-year backtest shows a typical error of ±17.6%, 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 →
20250.940.431.5
20260.960.451.5
20270.970.461.5
20280.980.481.5
20291.000.491.5

Ruby-throated Hummingbird Survey Routes in Delaware

Routes recording Ruby-throated Hummingbird 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 →
Frederica620141996
Milton320161968
Frankford220121968
Milton 2220172017
Mt Pleasant120141966
Wilmington120111977
Harrington120241969
Dover119871967
Holleyville120041968
Lowes Xrds119911969
Bethany Bch119661966
Blackbird120211996
Millsboro120242017
Holleyville 2120242015
Pepperbox120161998
Georgetown120221992
Pepperbox 2120242017

Ruby-throated Hummingbird Population Trend in Other States

alabamaarkansasconnecticutfloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourinebraskanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawest-virginiawisconsin

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