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

Nelson's Sparrow In Prairie Potholes

All regionsPrairie PotholesGeneralists

Nelson's Sparrow in Prairie Potholes has surged: up 349% on the route-weighted index since 1970.

+349%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 →
45Routes 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 →
52YearsYears 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 →

Nelson's Sparrow has surged in Prairie Potholes: up 349% on the route-weighted index since 1970.

Nelson's Sparrow In Prairie Potholes Population Forecast

If the recent trend holds, Nelson's Sparrow in Prairie Potholes is projected to rise about 113% by 2029 — from 0.13 in 2024 to a central estimate of 0.27 (95% range 0.09–0.45). A 5-year backtest shows a typical error of ±157.3%, with 40% of held-out values landing inside the 95% band.

+113%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 →
0.27Projected 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 →
0.09–0.4595% 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 →
±157.3%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, Nelson's Sparrow in Prairie Potholes is projected to rise about 113% by 2029 — from 0.13 in 2024 to a central estimate of 0.27 (95% range 0.09–0.45). A 5-year backtest shows a typical error of ±157.3%, with 40% 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 →
20250.260.070.44
20260.260.080.44
20270.260.080.45
20280.270.080.45
20290.270.090.45

Routes In Prairie Potholes

Routes recording Nelson's Sparrow in Prairie Potholes.
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 →
WestbyMONTANA42023
BeltramiMINNESOTA32001
EdgeleyNORTH-DAKOTA32024
WimbledonNORTH-DAKOTA32022
BuchananNORTH-DAKOTA32024
CooperstownNORTH-DAKOTA22022
BowesmontNORTH-DAKOTA21977
LakotaNORTH-DAKOTA22009
WebsterNORTH-DAKOTA22012
ReganNORTH-DAKOTA22000
DenbighNORTH-DAKOTA22022
Wild RoseNORTH-DAKOTA22022
Danzig 2NORTH-DAKOTA22023
ForbesSOUTH-DAKOTA22023
GlyndonMINNESOTA12007
WylieMINNESOTA11981
ErieMINNESOTA11996
GryglaMINNESOTA11979
BadgerMINNESOTA12000
Lake BronsonMINNESOTA11979
MaltaMONTANA12016
RedstoneMONTANA12023
FormanNORTH-DAKOTA12021
SydneyNORTH-DAKOTA11967
Lake GeorgeNORTH-DAKOTA12021

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