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

Bank Swallow Population Trend in Maryland

All statesAerial insectivores

Bank Swallow in Maryland has collapsed: down 82% on the route-weighted index since 1968.

-82%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 →
30Routes 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 →
57YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Bank Swallow 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 →

Bank Swallow has collapsed in Maryland: down 82% on the route-weighted index since 1968.

Bank Swallow Population Forecast in Maryland

If the recent trend holds, Bank Swallow in Maryland is projected to fall about 100% by 2029 — from 0.12 in 2024 to a central estimate of 0.00 (95% range 0.00–2.2). A 5-year backtest shows a typical error of ±301%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–2.295% 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 →
±301%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, Bank Swallow in Maryland is projected to fall about 100% by 2029 — from 0.12 in 2024 to a central estimate of 0.00 (95% range 0.00–2.2). A 5-year backtest shows a typical error of ±301%, 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 →
20250.000.002.2
20260.000.002.2
20270.000.002.2
20280.000.002.2
20290.000.002.2

Bank Swallow Survey Routes in Maryland

Routes recording Bank Swallow 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 →
Madonna6420102010
Piney Neck620191966
Northeast519941966
Matthews519661966
Davidsnville520241983
Williamsport420231986
Upper Xrds419701970
Jones419751975
Hughesville419971993
Theodore420131971
Millington420061968
Bachman Mill219941987
Van Bibber219661966
Broomes Isl219831971
Tall Timbers219721972
Elkton219681966
Harmony220171976
Emmitsburg120172017
Olney120152015
Pleasant Val119941967
Eklo119791979
Beltsville119901966
Pomfret120132013
Melitota119961967
Honga119891968

Bank Swallow Population Trend in Other States

alabamaalaskaarkansascaliforniacoloradoconnecticutdelawareidahoillinoisindianaiowakansaskentuckymainemassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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