BirdAnalyst
Species · Nevada · BBS 2026 Release · 1966–2025

Tree Swallow Population Trend in Nevada

All statesAerial insectivores

Tree Swallow in Nevada has fallen sharply: down 73% on the route-weighted index since 1973.

-73%Since 1973TrendPercent 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 →
15Routes 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 →
23YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Tree Swallow Trends in NevadaNotable 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 declinecomputed 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 →

Tree Swallow has fallen sharply in Nevada: down 73% on the route-weighted index since 1973.

Tree Swallow Population Forecast in Nevada

If the recent trend holds, Tree Swallow in Nevada is projected to fall about 29% by 2030 — from 0.33 in 2025 to a central estimate of 0.24 (95% range 0.00–1.8). A 5-year backtest shows a typical error of ±259.7%, with 100% of held-out values landing inside the 95% band.

-29%Change by 2030TrendPercent 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 →
0.24Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–1.895% 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 →
±259.7%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, Tree Swallow in Nevada is projected to fall about 29% by 2030 — from 0.33 in 2025 to a central estimate of 0.24 (95% range 0.00–1.8). A 5-year backtest shows a typical error of ±259.7%, with 100% of held-out values landing inside the 95% band.19682030
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 →
20260.270.001.8
20270.260.001.8
20280.250.001.8
20290.240.001.8
20300.240.001.8

Tree Swallow Survey Routes in Nevada

Routes recording Tree Swallow in Nevada.
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 →
Fallon8219981996
Dinner Sta2019681968
Ruby Valley1920001997
Majors Place720121971
Gardnerville 2720252025
Minerva620141991
Ruby Valley 2520072006
Jarbidge420122007
Comins Lake420122005
Nixon420211973
Gardnerville420062000
Sand Pass120182018
Rye Patch119731973
Humboldt Nf120052005
Mill City120132013

Tree Swallow Population Trend in Other States

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

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.