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Species · Massachusetts · BBS 2025 Release · 1966–2024

Cliff Swallow Population Trend in Massachusetts

All statesAerial insectivores

Cliff Swallow in Massachusetts has fallen sharply: down 61% on the route-weighted index since 1969.

-61%Since 1969
15Routes In State
38Years

Notable Cliff Swallow Trends in Massachusetts

long arc declinecomputed index

Cliff Swallow has fallen sharply in Massachusetts: down 61% on the route-weighted index since 1969.

Cliff Swallow Population Forecast in Massachusetts

If the recent trend holds, Cliff Swallow in Massachusetts is projected to fall about 95% by 2029 — from 0.33 in 2024 to a central estimate of 0.01 (95% range 0.00–0.54). A 5-year backtest shows a typical error of ±105.8%, with 100% of held-out values landing inside the 95% band.

-95%Change by 2029
0.01Projected 2029 index
0.00–0.5495% range
±105.8%Backtest error
19672029
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
20250.040.000.56
20260.030.000.56
20270.030.000.55
20280.020.000.54
20290.010.000.54

Cliff Swallow Survey Routes in Massachusetts

Routes recording Cliff Swallow in Massachusetts.
E Pepperell519811968
Cummington 2520242015
Cheshire419931970
Maynard219681968
S Barre219941972
N Orange219721969
Princeton119691969
Belchertown119921975
Warren119751969
Cummington119751975
Chesterfield120081967
Pittsfield119971978
Sheffield120131974
Holden119831981
Hancock120002000

Cliff Swallow Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniasouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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