BirdAnalyst
Species · Maryland · BBS 2026 Release · 1966–2025

Purple Martin Population Trend in Maryland

All statesAerial insectivores

Purple Martin in Maryland has surged: up 93% on the route-weighted index since 1968.

+93%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 →
72Routes 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 →
59YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Purple Martin 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 →

Purple Martin has surged in Maryland: up 93% on the route-weighted index since 1968.

Purple Martin Population Forecast in Maryland

If the recent trend holds, Purple Martin in Maryland is projected to stay roughly flat through 2030, near 12 (95% range 9.9–15). A 5-year backtest shows a typical error of ±7.8%, with 100% of held-out values landing inside the 95% band.

-8%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 →
12Projected 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 →
9.9–1595% 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 →
±7.8%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, Purple Martin in Maryland is projected to stay roughly flat through 2030, near 12 (95% range 9.9–15). A 5-year backtest shows a typical error of ±7.8%, with 100% 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 →
2026129.514
2027129.615
2028129.715
2029129.815
2030129.915

Purple Martin Survey Routes in Maryland

Routes recording Purple Martin 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 →
Cokesbury9020251966
Honga8120251966
Madison7320251966
Harmony6820171966
Easton3820251969
Melitota3520251966
Vienna3320251966
Indiantown3220141977
Newark3120251967
Forest Grove3020232011
Broomes Isl2519961966
Furnace Town2520252015
St. George'S Island2320172015
Madonna1920222009
Piney Neck1620251966
Matthews1620251966
Fruitland1519981966
Grove Neck1419961992
Golden Hill1320251966
Walnut1320241999
Pt Republic1219891967
Emmitsburg1120251967
Silver Spg1119891966
Tall Timbers1120141966
Van Bibber820131966

Purple Martin Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemassachusettsmichiganminnesotamississippimissourimontananebraskanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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