BirdAnalyst
Species · BCR 26 · BBS 2025 Release · 1966–2024

Tree Swallow In Mississippi Alluvial Valley

All regionsMississippi Alluvial ValleyAerial insectivores

Tree Swallow in Mississippi Alluvial Valley has surged: up 138% on the route-weighted index since 1975.

+138%Since 1975TrendPercent 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 →
24Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
44YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable SignalsNotable 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 →

Tree Swallow has surged in Mississippi Alluvial Valley: up 138% on the route-weighted index since 1975.

Tree Swallow In Mississippi Alluvial Valley Population Forecast

If the recent trend holds, Tree Swallow in Mississippi Alluvial Valley is projected to fall about 70% by 2029 — from 0.55 in 2024 to a central estimate of 0.16 (95% range 0.00–0.66). A 5-year backtest shows a typical error of ±41.7%, with 100% of held-out values landing inside the 95% band.

-70%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 →
0.16Projected 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 →
0.00–0.6695% 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 →
±41.7%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 Mississippi Alluvial Valley is projected to fall about 70% by 2029 — from 0.55 in 2024 to a central estimate of 0.16 (95% range 0.00–0.66). A 5-year backtest shows a typical error of ±41.7%, with 100% of held-out values landing inside the 95% band.19732029
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 →
20250.170.000.67
20260.170.000.67
20270.170.000.67
20280.170.000.67
20290.160.000.66

Routes In Mississippi Alluvial Valley

Routes recording Tree Swallow in Mississippi Alluvial Valley.
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 →
Tensas NwrLOUISIANA82024
MaynardARKANSAS42024
Tchula 3MISSISSIPPI42024
HarrisburgARKANSAS31985
South BendARKANSAS22023
Bardwell 2KENTUCKY22022
TallahatchieMISSISSIPPI22009
TiptonvilleTENNESSEE22021
HughesARKANSAS12011
AugustaARKANSAS11995
SaffellARKANSAS12004
LafeARKANSAS12022
GillettARKANSAS12016
UlmARKANSAS12024
WilsonARKANSAS12024
BardwellKENTUCKY12003
ShawLOUISIANA12021
RayvilleLOUISIANA11994
IsolaMISSISSIPPI12000
TippoMISSISSIPPI12023
DeventerMISSOURI12021
Cp GirardeauMISSOURI12007
PawpawTENNESSEE12008
Pawpaw 2TENNESSEE12018

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