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Species · Delaware · BBS 2026 Release · 1966–2025

Louisiana Waterthrush Population Trend in Delaware

All statesForest birds

Louisiana Waterthrush in Delaware has increased: up 41% on the route-weighted index since 1968.

+41%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 →
12Routes 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 →
35YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Louisiana Waterthrush 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 Louisiana Waterthrush in Delaware. See the full index history below.

Louisiana Waterthrush Population Forecast in Delaware

If the recent trend holds, Louisiana Waterthrush in Delaware is projected to fall about 64% by 2030 — from 0.83 in 2025 to a central estimate of 0.30 (95% range 0.00–0.66). A 5-year backtest shows a typical error of ±58.9%, with 80% of held-out values landing inside the 95% band.

-64%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 →
0.30Projected 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 →
0.00–0.6695% 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 →
±58.9%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, Louisiana Waterthrush in Delaware is projected to fall about 64% by 2030 — from 0.83 in 2025 to a central estimate of 0.30 (95% range 0.00–0.66). A 5-year backtest shows a typical error of ±58.9%, with 80% 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 →
20260.300.000.66
20270.300.000.66
20280.300.000.66
20290.300.000.66
20300.300.000.66

Louisiana Waterthrush Survey Routes in Delaware

Routes recording Louisiana Waterthrush 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 →
Harrington220251970
Lowes Xrds219741966
Milton 2220252025
Mt Pleasant119931966
Frederica119671967
Frankford120121968
Holleyville120041967
Milton119791979
Millsboro120242024
Pepperbox120161998
Georgetown120051998
Pepperbox 2120252018

Louisiana Waterthrush Population Trend in Other States

alabamaarkansasconnecticutfloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourinew-hampshirenew-jerseynew-yorknorth-carolinaohiooklahomapennsylvaniarhode-islandsouth-carolinatennesseetexasvermontvirginiawest-virginiawisconsin

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