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Species · Louisiana · BBS 2025 Release · 1966–2024

Cliff Swallow Population Trend in Louisiana

All statesAerial insectivores

Cliff Swallow in Louisiana has surged: up 38× on the route-weighted index since 1994.

38×Since 1994TrendPercent 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 →
62Routes 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 →
32YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Cliff 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 →

Cliff Swallow has surged in Louisiana: up 38× on the route-weighted index since 1994.

Cliff Swallow Population Forecast in Louisiana

If the recent trend holds, Cliff Swallow in Louisiana is projected to rise about 14% by 2029 — from 13 in 2024 to a central estimate of 15 (95% range 12–18). A 5-year backtest shows a typical error of ±10.8%, with 100% of held-out values landing inside the 95% band.

+14%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 →
15Projected 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 →
12–1895% 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 →
±10.8%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, Cliff Swallow in Louisiana is projected to rise about 14% by 2029 — from 13 in 2024 to a central estimate of 15 (95% range 12–18). A 5-year backtest shows a typical error of ±10.8%, with 100% of held-out values landing inside the 95% band.19892029
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 →
2025131016
2026141017
2027141117
2028141118
2029151218

Cliff Swallow Survey Routes in Louisiana

Routes recording Cliff 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 →
Woodlawn11120212008
Forked Island10620242008
Natchez8520241993
Plettenberg6020222009
Flat Creek5520242010
Brousville4420242013
Zwolle4120161998
Mayflower3320242011
Bickham3220242007
Ramah3220242012
Tensas Nwr3020062006
Cheniere3020242017
Burr Ferry2720222018
Mer Rouge2520082002
Shaw2320242006
Morgan City2020222011
Derry 22020241995
Forked Island 21920112010
Hackberry1820142004
Port Allen1520242006
Hackberry 21520182018
Kaplan1420232011
River Road1320242003
Longstreet1320232016
Rayville 21220242018

Cliff Swallow Population Trend in Other States

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

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