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Species · Maryland · BBS 2025 Release · 1966–2024

Kentucky Warbler Population Trend in Maryland

All statesForest birds

Kentucky Warbler in Maryland has fallen sharply: down 74% on the route-weighted index since 1968.

-74%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 →
74Routes 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 Kentucky Warbler Trends in MarylandNotable 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 declinecomputed 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 →

Kentucky Warbler has fallen sharply in Maryland: down 74% on the route-weighted index since 1968.

Kentucky Warbler Population Forecast in Maryland

If the recent trend holds, Kentucky Warbler in Maryland is projected to stay roughly flat through 2029, near 0.27 (95% range 0.00–0.85). A 5-year backtest shows a typical error of ±17.5%, with 100% of held-out values landing inside the 95% band.

-7%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 →
0.27Projected 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 →
0.00–0.8595% 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 →
±17.5%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, Kentucky Warbler in Maryland is projected to stay roughly flat through 2029, near 0.27 (95% range 0.00–0.85). A 5-year backtest shows a typical error of ±17.5%, 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 →
20250.340.000.92
20260.320.000.90
20270.300.000.88
20280.280.000.87
20290.270.000.85

Kentucky Warbler Survey Routes in Maryland

Routes recording Kentucky Warbler in Maryland.
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 →
Pr Frederick620241991
Pt Republic519891966
Snow Hill419761966
Bald Friar419961992
Broomes Isl319911966
Easton320211966
Sinepuxent319781966
Oldtown220071973
Norwood219801980
Pleasant Val220051967
Pomonkey220211966
Melitota219961966
Harmony220171966
Vienna220241966
Mardela219821971
Newark220131966
Forest Grove220232011
Jessup220152015
Grove Neck219951994
Davidsnville220101982
Floyd120091970
Mt Nebo119911969
Vindex120171982
Potomac Park120231976
Williamsport120072007

Kentucky Warbler Population Trend in Other States

alabamaarkansasdelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamississippimissourinew-jerseynew-yorknorth-carolinaohiooklahomapennsylvaniasouth-carolinatennesseetexasvirginiawest-virginiawisconsin

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