BirdAnalyst
Species · BCR 16 · BBS 2025 Release · 1966–2024

Cassin's Sparrow In Southern Rockies / Colorado Plateau

All regionsSouthern Rockies / Colorado PlateauGrassland birds

Cassin's Sparrow in Southern Rockies / Colorado Plateau has surged: up 213% on the route-weighted index since 1976.

+213%Since 1976TrendPercent 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 →
31Routes 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 →
46YearsYears 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 →

Cassin's Sparrow has surged in Southern Rockies / Colorado Plateau: up 213% on the route-weighted index since 1976.

Forecast

If the recent trend holds, Cassin's Sparrow in Southern Rockies / Colorado Plateau is projected to rise about 97% by 2029 — from 0.76 in 2024 to a central estimate of 1.5 (95% range 0.10–2.9). A 5-year backtest shows a typical error of ±1148.8%, with 40% of held-out values landing inside the 95% band.

+97%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 →
1.5Projected 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 →
0.10–2.995% 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 →
±1148.8%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, Cassin's Sparrow in Southern Rockies / Colorado Plateau is projected to rise about 97% by 2029 — from 0.76 in 2024 to a central estimate of 1.5 (95% range 0.10–2.9). A 5-year backtest shows a typical error of ±1148.8%, with 40% of held-out values landing inside the 95% band.19712029
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 →
20251.40.002.8
20261.40.032.8
20271.50.052.9
20281.50.072.9
20291.50.102.9

Routes In Southern Rockies / Colorado Plateau

Routes recording Cassin's Sparrow in Southern Rockies / Colorado Plateau.
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 →
PasturaNEW-MEXICO702024
Corona EastNEW-MEXICO641995
Horse MtnNEW-MEXICO122023
PecosNEW-MEXICO112017
MountainairNEW-MEXICO112024
TorreonNEW-MEXICO102024
Cerro VerdeNEW-MEXICO102019
LudlowCOLORADO52011
ValenciaNEW-MEXICO41995
Gallo ArroyoNEW-MEXICO42021
NageesiNEW-MEXICO32024
La CienegaNEW-MEXICO32022
CounselorNEW-MEXICO32019
CebollaNEW-MEXICO22006
CrownpointNEW-MEXICO21992
DulceNEW-MEXICO22018
La PlataNEW-MEXICO22010
Salt Lake 2NEW-MEXICO22024
The GapARIZONA11971
AlamosaCOLORADO12012
San LuisCOLORADO12024
AntonitoCOLORADO12004
WalsenburgCOLORADO12019
GardnerCOLORADO12024
MesitaCOLORADO12017

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