BirdAnalyst
Species · Tennessee · BBS 2025 Release · 1966–2024

Rose-breasted Grosbeak Population Trend in Tennessee

All statesGeneralists

Rose-breasted Grosbeak in Tennessee has surged: up 84% on the route-weighted index since 1979.

+84%Since 1979TrendPercent 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 →
7Routes 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 →
31YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Rose-breasted Grosbeak Trends in TennesseeNotable 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 →

Rose-breasted Grosbeak has surged in Tennessee: up 84% on the route-weighted index since 1979.

Rose-breasted Grosbeak Population Forecast in Tennessee

If the recent trend holds, Rose-breasted Grosbeak in Tennessee is projected to stay roughly flat through 2029, near 0.09 (95% range 0.02–0.15). A 5-year backtest shows a typical error of ±50.5%, with 100% of held-out values landing inside the 95% band.

-5%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 →
0.09Projected 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 →
0.02–0.1595% 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 →
±50.5%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, Rose-breasted Grosbeak in Tennessee is projected to stay roughly flat through 2029, near 0.09 (95% range 0.02–0.15). A 5-year backtest shows a typical error of ±50.5%, with 100% of held-out values landing inside the 95% band.19742029
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 →
20250.080.010.15
20260.080.020.15
20270.090.020.15
20280.090.020.15
20290.090.020.15

Rose-breasted Grosbeak Survey Routes in Tennessee

Routes recording Rose-breasted Grosbeak in Tennessee.
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 →
Newfound Gap220241990
Cades Cove220042004
Fish Springs220231974
Willis Sprng120182018
Mecca119971997
Tellico120211995
Elk Valley120211979

Rose-breasted Grosbeak Population Trend in Other States

arkansasconnecticutgeorgiaillinoisindianaiowakansaskentuckymainemarylandmassachusettsmichiganminnesotamissourinebraskanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-dakotavermontvirginiawest-virginiawisconsinwyoming

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