BirdAnalyst
Species · BCR 11 · BBS 2026 Release · 1966–2025

Purple Martin In Prairie Potholes

All regionsPrairie PotholesAerial insectivores

Purple Martin in Prairie Potholes has declined: down 38% on the route-weighted index since 1969.

-38%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 →
74Routes 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 →
58YearsYears 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 →

No notable trend signals for Purple Martin in Prairie Potholes. See the full index history below.

Purple Martin In Prairie Potholes Population Forecast

If the recent trend holds, Purple Martin in Prairie Potholes is projected to fall about 32% by 2030 — from 0.61 in 2025 to a central estimate of 0.41 (95% range 0.00–0.98). A 5-year backtest shows a typical error of ±35%, with 100% of held-out values landing inside the 95% band.

-32%Change by 2030TrendPercent 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 →
0.41Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.9895% 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 →
±35%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, Purple Martin in Prairie Potholes is projected to fall about 32% by 2030 — from 0.61 in 2025 to a central estimate of 0.41 (95% range 0.00–0.98). A 5-year backtest shows a typical error of ±35%, with 100% of held-out values landing inside the 95% band.19672030
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 →
20260.470.001.0
20270.450.001.0
20280.440.001.0
20290.430.000.99
20300.410.000.98

Routes In Prairie Potholes

Routes recording Purple Martin 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 →
Turtle MtnsNORTH-DAKOTA282025
ScrantonIOWA171999
TrippSOUTH-DAKOTA151988
ErieMINNESOTA101997
BowesmontNORTH-DAKOTA101995
BroadlandSOUTH-DAKOTA101969
LennoxSOUTH-DAKOTA82024
OkleeMINNESOTA71993
ChokioMINNESOTA62025
SpartaNEBRASKA62019
TitonkaIOWA51981
Eagle CreekNEBRASKA51975
NilesNORTH-DAKOTA52021
LoraineNORTH-DAKOTA52019
AbercrombieNORTH-DAKOTA52012
GeddesSOUTH-DAKOTA41970
HartlandMINNESOTA32017
BeltramiMINNESOTA32025
RedstoneMONTANA32021
FormanNORTH-DAKOTA31992
WashingtonIOWA22024
KanawhaIOWA21986
ClareIOWA22009
GarnerIOWA21990
HuntleyMINNESOTA21981

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.