BirdAnalyst
Species · BCR 11 · BBS 2025 Release · 1966–2024

Thick-billed Longspur In Prairie Potholes

All regionsPrairie PotholesGeneralists

Thick-billed Longspur in Prairie Potholes has surged: up 371% on the route-weighted index since 1972.

+371%Since 1972
16Routes In Region
53Years

Notable Signals

long arc increasecomputed index

Thick-billed Longspur has surged in Prairie Potholes: up 371% on the route-weighted index since 1972.

Forecast

If the recent trend holds, Thick-billed Longspur in Prairie Potholes is projected to fall about 50% by 2029 — from 3.0 in 2024 to a central estimate of 1.5 (95% range 0.27–2.7). A 5-year backtest shows a typical error of ±42.2%, with 60% of held-out values landing inside the 95% band.

-50%Change by 2029
1.5Projected 2029 index
0.27–2.795% range
±42.2%Backtest error
19702029
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected index95% low95% high
20251.40.182.6
20261.40.202.6
20271.40.232.6
20281.50.252.7
20291.50.272.7

Routes In Prairie Potholes

Routes recording Thick-billed Longspur in Prairie Potholes.
WhitlashMONTANA642024
VirgelleMONTANA532024
GildfordMONTANA332024
HarlemMONTANA202021
GlentanaMONTANA192024
GlasgowMONTANA142024
OswegoMONTANA142024
ShelbyMONTANA132024
Hay LakeMONTANA52022
ChinookMONTANA52023
Sun RiverMONTANA32017
SunburstMONTANA21987
MaltaMONTANA21987
ClevelandMONTANA11979
RedstoneMONTANA12018
Great FallsMONTANA12004

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