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

Osprey Population Trend in Maryland

All statesGeneralists

Osprey in Maryland has surged: up 12× on the route-weighted index since 1968.

12×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 →
47Routes 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 Osprey 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 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 →

Osprey has surged in Maryland: up 12× on the route-weighted index since 1968.

Osprey Population Forecast in Maryland

If the recent trend holds, Osprey in Maryland is projected to rise about 29% by 2029 — from 2.1 in 2024 to a central estimate of 2.7 (95% range 1.9–3.5). A 5-year backtest shows a typical error of ±20.6%, with 100% of held-out values landing inside the 95% band.

+29%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 →
2.7Projected 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 →
1.9–3.595% 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 →
±20.6%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, Osprey in Maryland is projected to rise about 29% by 2029 — from 2.1 in 2024 to a central estimate of 2.7 (95% range 1.9–3.5). A 5-year backtest shows a typical error of ±20.6%, 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 →
20252.51.73.3
20262.51.83.3
20272.61.83.4
20282.61.83.4
20292.71.93.5

Osprey Survey Routes in Maryland

Routes recording Osprey 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 →
St. George'S Island5720172015
Honga2320241966
Piney Neck1320241966
Madison1220241969
Melitota1120241966
Tall Timbers1020141967
Millington820241966
Elkton720241985
Broomes Isl619961967
Harmony520171967
Walnut420191999
Golden Hill420231979
Earlton320242014
Fair Hill219961992
Van Bibber220132003
Berlin220101980
Beltsville220122011
Easton220191974
Vienna220241980
Mardela220192019
Davidsnville220241995
Island Creek220242000
Pr Frederick220242002
Grove Neck119921992
Bald Friar119961994

Osprey Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakentuckylouisianamainemassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinaohiooregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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