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Species · Maryland · BBS 2025 Release · 1966–2024

Ruby-throated Hummingbird Population Trend in Maryland

All statesGeneralists

Ruby-throated Hummingbird in Maryland has surged: up 169% on the route-weighted index since 1968.

+169%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 →
71Routes 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 Ruby-throated Hummingbird 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 →

Ruby-throated Hummingbird has surged in Maryland: up 169% on the route-weighted index since 1968.

Ruby-throated Hummingbird Population Forecast in Maryland

If the recent trend holds, Ruby-throated Hummingbird in Maryland is projected to rise about 28% by 2029 — from 0.91 in 2024 to a central estimate of 1.2 (95% range 0.69–1.6). A 5-year backtest shows a typical error of ±17.3%, with 80% of held-out values landing inside the 95% band.

+28%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 →
1.2Projected 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 →
0.69–1.695% 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 →
±17.3%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, Ruby-throated Hummingbird in Maryland is projected to rise about 28% by 2029 — from 0.91 in 2024 to a central estimate of 1.2 (95% range 0.69–1.6). A 5-year backtest shows a typical error of ±17.3%, with 80% 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 →
20251.10.641.6
20261.10.651.6
20271.10.661.6
20281.10.681.6
20291.20.691.6

Ruby-throated Hummingbird Survey Routes in Maryland

Routes recording Ruby-throated Hummingbird 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 →
Finzel620241996
Harmony520171968
Forest Grove520232011
Island Creek520241994
Williamsport320231981
Smithsburg320111976
Broomes Isl319961968
Vindex220171970
Emmitsburg220241968
Olney220241976
Eklo220181966
Tall Timbers220141969
Pomonkey220241966
Pomfret220221966
Elkton220221966
Madison220241967
Cokesbury220241967
Newark220241966
Snow Hill219741966
Jennings220241995
Green Ridge220241996
St. George'S Island220172015
Furnace Town220242016
Earlton220222014
Madonna220222010

Ruby-throated Hummingbird Population Trend in Other States

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

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