BirdAnalyst
Species · BCR 10 · BBS 2025 Release · 1966–2024

Bobolink In Northern Rockies

All regionsNorthern RockiesGrassland birds

Bobolink in Northern Rockies has surged: up 134% on the route-weighted index since 1970.

+134%Since 1970TrendPercent 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 →
53Routes 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 →
56YearsYears 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 →

Bobolink has surged in Northern Rockies: up 134% on the route-weighted index since 1970.

Bobolink In Northern Rockies Population Forecast

If the recent trend holds, Bobolink in Northern Rockies is projected to fall about 37% by 2029 — from 0.64 in 2024 to a central estimate of 0.40 (95% range 0.02–0.79). A 5-year backtest shows a typical error of ±39.9%, with 80% of held-out values landing inside the 95% band.

-37%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 →
0.40Projected 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 →
0.02–0.7995% 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 →
±39.9%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, Bobolink in Northern Rockies is projected to fall about 37% by 2029 — from 0.64 in 2024 to a central estimate of 0.40 (95% range 0.02–0.79). A 5-year backtest shows a typical error of ±39.9%, with 80% of held-out values landing inside the 95% band.19682029
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 →
20250.400.020.79
20260.400.020.79
20270.400.020.79
20280.400.020.79
20290.400.020.79

Routes In Northern Rockies

Routes recording Bobolink in Northern Rockies.
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 →
RaynesfordMONTANA452024
SulaMONTANA92024
Wolf CreekMONTANA72019
AugustaMONTANA62024
VictorMONTANA52024
CoolinIDAHO42024
Willow CreekMONTANA41981
Fort LoganMONTANA42024
WickiupOREGON42003
BridgeportOREGON42022
NaplesIDAHO32024
CabartonIDAHO32023
EllistonMONTANA32024
BoulderMONTANA32024
Saleratus CrUTAH31997
LaurierWASHINGTON31995
MidvaleWYOMING31975
TensleepWYOMING32023
MaybellCOLORADO22017
Browns ParkCOLORADO21995
LaurelMONTANA22022
Pablo Res.MONTANA22023
GlenMONTANA22022
PhilipsburgMONTANA22024
Threemile WaMONTANA22024

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