BirdAnalyst
Species · BCR 35 · BBS 2025 Release · 1966–2024

Blue Grosbeak In Chihuahuan Desert

All regionsChihuahuan DesertGeneralists

Blue Grosbeak in Chihuahuan Desert has surged: up 239% on the route-weighted index since 1969.

+239%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 →
56Routes 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 →
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 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 →

Blue Grosbeak has surged in Chihuahuan Desert: up 239% on the route-weighted index since 1969.

Forecast

If the recent trend holds, Blue Grosbeak in Chihuahuan Desert is projected to rise about 46% by 2029 — from 7.1 in 2024 to a central estimate of 10 (95% range 7.0–14). A 5-year backtest shows a typical error of ±26.5%, with 100% of held-out values landing inside the 95% band.

+46%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 →
10Projected 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 →
7.0–1495% 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 →
±26.5%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, Blue Grosbeak in Chihuahuan Desert is projected to rise about 46% by 2029 — from 7.1 in 2024 to a central estimate of 10 (95% range 7.0–14). A 5-year backtest shows a typical error of ±26.5%, with 100% 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 →
20259.86.413
202610.06.613
2027106.713
2028106.914
2029107.014

Routes In Chihuahuan Desert

Routes recording Blue Grosbeak in Chihuahuan Desert.
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 →
LaborcitaNEW-MEXICO382019
Quitman Cyn.TEXAS352009
Laborcita 2NEW-MEXICO342024
Casa PiedraTEXAS202023
Bear MtnTEXAS202024
Coyanda DrawTEXAS182024
Capitan Mtn.NEW-MEXICO172017
Quitman Canyon 2TEXAS172024
San AntonioNEW-MEXICO161977
Delaware CrkTEXAS142015
LangtryTEXAS132000
Ft. DavisTEXAS132023
MesillaNEW-MEXICO122000
PresidioTEXAS122023
Van HornTEXAS122024
LongfellowTEXAS102024
OzonaTEXAS102022
PumpvilleTEXAS102024
RoswellNEW-MEXICO92023
Bitter LakeNEW-MEXICO92023
Red RockNEW-MEXICO92024
QueenNEW-MEXICO92021
Devils R CynTEXAS92024
LakewoodNEW-MEXICO82021
Sierra BlancTEXAS82024

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