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Species · Louisiana · BBS 2025 Release · 1966–2024

Northern Rough-winged Swallow Population Trend in Louisiana

All statesAerial insectivores

Northern Rough-winged Swallow in Louisiana has surged: up 220% on the route-weighted index since 1969.

+220%Since 1969TrendPercent 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 →
65Routes 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 →
57YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Northern Rough-winged Swallow Trends in LouisianaNotable 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 →

Northern Rough-winged Swallow has surged in Louisiana: up 220% on the route-weighted index since 1969.

Northern Rough-winged Swallow Population Forecast in Louisiana

If the recent trend holds, Northern Rough-winged Swallow in Louisiana is projected to rise about 25% by 2029 — from 1.8 in 2024 to a central estimate of 2.3 (95% range 0.03–4.6). A 5-year backtest shows a typical error of ±31%, with 100% of held-out values landing inside the 95% band.

+25%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 →
2.3Projected 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 →
0.03–4.695% 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 →
±31%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, Northern Rough-winged Swallow in Louisiana is projected to rise about 25% by 2029 — from 1.8 in 2024 to a central estimate of 2.3 (95% range 0.03–4.6). A 5-year backtest shows a typical error of ±31%, with 100% of held-out values landing inside the 95% band.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 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 →
20252.20.004.4
20262.20.004.5
20272.20.004.5
20282.30.004.5
20292.30.034.6

Northern Rough-winged Swallow Survey Routes in Louisiana

Routes recording Northern Rough-winged Swallow in Louisiana.
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 →
Shaw3820241967
Keystone3120041968
Mamou3019821978
Frogmore1020242010
Transylvania1020222008
Mayflower720241973
Morgan City620182012
Easton519901970
Mer Rouge519841982
Fillmore519871968
Ramah520241988
Port Allen520222003
Bickham420241987
Haughton320241991
Roseland319981974
Derry319891969
Fishville320141969
Concord320192013
River Road220211987
Plettenberg220131968
Linville220061998
Fort Polk219731973
Chatham219691969
Clay219851972
Larose219881988

Northern Rough-winged Swallow Population Trend in Other States

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

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