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

Barn Swallow Population Trend in New Jersey

All statesAerial insectivores

Barn Swallow in New Jersey has edged down: down 16% on the route-weighted index since 1968.

-16%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 →
42Routes 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 →
58YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Barn Swallow Trends in New JerseyNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

No notable trend signals for Barn Swallow in New Jersey. See the full index history below.

Barn Swallow Population Forecast in New Jersey

If the recent trend holds, Barn Swallow in New Jersey is projected to rise about 11% by 2029 — from 9.0 in 2024 to a central estimate of 9.9 (95% range 5.4–14). A 5-year backtest shows a typical error of ±9%, with 100% of held-out values landing inside the 95% band.

+11%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 →
9.9Projected 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 →
5.4–1495% 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 →
±9%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, Barn Swallow in New Jersey is projected to rise about 11% by 2029 — from 9.0 in 2024 to a central estimate of 9.9 (95% range 5.4–14). A 5-year backtest shows a typical error of ±9%, 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 →
2025105.715
2026105.615
2027105.515
2028105.515
20299.95.414

Barn Swallow Survey Routes in New Jersey

Routes recording Barn Swallow in New Jersey.
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 →
Clarksville3719911969
Deepwater3519771969
Ocean City3220241979
Pedricktown 22620242013
Keyport2520221986
Cape May Ch2420131992
Woodbury Hgt2320241967
Pedricktown2220121991
Greenwich1920241966
Hope1719941970
Mt Misery1619891976
Masonville1519701966
Six Points1420241978
Kemah Lake1420241966
Dover1420231977
Roosevelt1420221986
Villas1319811979
Gillette1220241988
High Point1120241977
Del Haven1019911991
Croton920031970
Sandbrook720241969
Pottersville620241977
Spraguetown619931977
Winslow620241989

Barn Swallow Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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