BirdAnalyst
Species · BCR 17 · BBS 2025 Release · 1966–2024

Thick-billed Longspur In Badlands and Prairies

All regionsBadlands and PrairiesGeneralists

Thick-billed Longspur in Badlands and Prairies has surged: up 27× on the route-weighted index since 1969.

27×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 →
33Routes 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 →

Thick-billed Longspur has surged in Badlands and Prairies: up 27× on the route-weighted index since 1969.

Thick-billed Longspur In Badlands and Prairies Population Forecast

If the recent trend holds, Thick-billed Longspur in Badlands and Prairies is projected to fall about 59% by 2029 — from 4.6 in 2024 to a central estimate of 1.9 (95% range 0.28–3.5). A 5-year backtest shows a typical error of ±65.8%, with 20% of held-out values landing inside the 95% band.

-59%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 →
1.9Projected 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 →
0.28–3.595% 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 →
±65.8%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, Thick-billed Longspur in Badlands and Prairies is projected to fall about 59% by 2029 — from 4.6 in 2024 to a central estimate of 1.9 (95% range 0.28–3.5). A 5-year backtest shows a typical error of ±65.8%, with 20% 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 →
20251.80.163.4
20261.80.193.4
20271.80.223.4
20281.90.253.5
20291.90.283.5

Routes In Badlands and Prairies

Routes recording Thick-billed Longspur in Badlands and Prairies.
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 →
RoundupMONTANA1652024
Maynard CouleeMONTANA1432024
Coleman CouleeMONTANA302023
Pine TreeWYOMING261995
PineyWYOMING191990
SavagetonWYOMING162019
Dinosaurs H.M.MONTANA122024
LuskWYOMING112023
NewcastleWYOMING101988
GlenrockWYOMING91977
ShawneeWYOMING72015
RozetWYOMING51991
Wheat BasinMONTANA42017
GorhamNORTH-DAKOTA41986
Two DotMONTANA31981
BowmanNORTH-DAKOTA31997
Harland FlatWYOMING31995
Oglala Nat. Grass.NEBRASKA22014
NatronaWYOMING21986
UptonWYOMING21989
Seely 2WYOMING22010
RoyMONTANA12019
CircleMONTANA12018
ShawmutMONTANA12023
FlatwillowMONTANA11997

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