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

Tree Swallow Population Trend in Maryland

All statesAerial insectivores

Tree Swallow in Maryland has surged: up 518% on the route-weighted index since 1968.

+518%Since 1968
71Routes In State
58Years

Notable Tree Swallow Trends in Maryland

long arc increasecomputed index

Tree Swallow has surged in Maryland: up 518% on the route-weighted index since 1968.

Tree Swallow Population Forecast in Maryland

If the recent trend holds, Tree Swallow in Maryland is projected to rise about 18% by 2029 — from 3.3 in 2024 to a central estimate of 3.9 (95% range 2.9–4.8). A 5-year backtest shows a typical error of ±11.3%, with 100% of held-out values landing inside the 95% band.

+18%Change by 2029
3.9Projected 2029 index
2.9–4.895% range
±11.3%Backtest error
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 index95% low95% high
20253.62.74.5
20263.72.74.6
20273.72.84.7
20283.82.94.7
20293.92.94.8

Tree Swallow Survey Routes in Maryland

Routes recording Tree Swallow in Maryland.
Madison2920241966
Smithsburg2520131996
Honga2520241968
Jessup1320242015
Earlton1220242014
Van Bibber820131978
Newark620241970
Furnace Town620242017
Wolfsville520241986
Warfieldsbrg520232003
Forest Grove520232011
Vindex420221975
Emmitsburg420241994
Eklo420171997
Accident420151992
Potomac Park320241986
Silver Spg319821977
Olney320241987
Millington320241967
Cokesbury320241973
Severna Park320012001
Williamsport220241992
Pleasant Val220231973
Bachman Mill220221991
Fowblesburg220171994

Tree Swallow Population Trend in Other States

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

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