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Species · Louisiana · BBS 2025 Release · 1966–2024

Blue-gray Gnatcatcher Population Trend in Louisiana

All statesForest birds

Blue-gray Gnatcatcher in Louisiana has surged: up 328% on the route-weighted index since 1969.

+328%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 →
83Routes 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 Blue-gray Gnatcatcher 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 →

Blue-gray Gnatcatcher has surged in Louisiana: up 328% on the route-weighted index since 1969.

Blue-gray Gnatcatcher Population Forecast in Louisiana

If the recent trend holds, Blue-gray Gnatcatcher in Louisiana is projected to fall about 12% by 2029 — from 5.6 in 2024 to a central estimate of 4.9 (95% range 2.9–6.9). A 5-year backtest shows a typical error of ±30.3%, with 80% of held-out values landing inside the 95% band.

-12%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 →
4.9Projected 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 →
2.9–6.995% 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 →
±30.3%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, Blue-gray Gnatcatcher in Louisiana is projected to fall about 12% by 2029 — from 5.6 in 2024 to a central estimate of 4.9 (95% range 2.9–6.9). A 5-year backtest shows a typical error of ±30.3%, with 80% 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 →
20254.72.76.7
20264.72.76.8
20274.82.86.8
20284.92.86.9
20294.92.96.9

Blue-gray Gnatcatcher Survey Routes in Louisiana

Routes recording Blue-gray Gnatcatcher 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 →
Carterville2719921992
Mount Union2220241998
Womack2120241999
Ivan2120131998
Linville1820241998
Clay1720241968
Ivan 21620162014
Goodwill1620242004
Marion1419961988
Cheniere1220241985
Atchafalaya1220241989
Fillmore1119891968
Evelyn1120242004
Freetown1020091984
Flat Creek1020241998
Burr Ferry1020241987
Natchez920241993
Hargis 2920142013
Many819921991
Norwood820242006
Longstreet720241967
Ramah720241988
Fort Jessup720231998
Hargis720112006
Lake Cove720172008

Blue-gray Gnatcatcher Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckymainemarylandmassachusettsmichiganminnesotamississippimissourinebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawest-virginiawisconsinwyoming

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