BirdAnalyst
Species · New Hampshire · BBS 2025 Release · 1966–2024

Cliff Swallow Population Trend in New Hampshire

All statesAerial insectivores

Cliff Swallow in New Hampshire has collapsed: down 93% on the route-weighted index since 1968.

-93%Since 1968
22Routes In State
58Years

Notable Cliff Swallow Trends in New Hampshire

long arc declinecomputed index

Cliff Swallow has collapsed in New Hampshire: down 93% on the route-weighted index since 1968.

Cliff Swallow Population Forecast in New Hampshire

If the recent trend holds, Cliff Swallow in New Hampshire is projected to fall about 100% by 2029 — from 0.32 in 2024 to a central estimate of 0.00 (95% range 0.00–3.1). A 5-year backtest shows a typical error of ±364.8%, with 100% of held-out values landing inside the 95% band.

-100%Change by 2029
0.00Projected 2029 index
0.00–3.195% range
±364.8%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
20250.000.003.1
20260.000.003.1
20270.000.003.1
20280.000.003.1
20290.000.003.1

Cliff Swallow Survey Routes in New Hampshire

Routes recording Cliff Swallow in New Hampshire.
Wilmot819741966
Milan720241966
Peterborough419801968
Gilmantn I W319741971
Crawford Not319751972
Franconia319951969
Brentwood219851985
Fitzwilliam219851966
Marlow219951966
Jefferson Hl220071966
Stratford220061966
Dixvil Notch220051966
Clarksville220221966
Glen220071976
Dover120081966
Hopkinton120071968
Epsom120071976
Concord119711971
Canterbury119771972
Mt Chocorua120061967
Walpole119761972
Lempster119891969

Cliff Swallow Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniasouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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