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

Purple Martin In Prairie Potholes

All regionsPrairie PotholesAerial insectivores

Purple Martin in Prairie Potholes has declined: down 34% on the route-weighted index since 1969.

-34%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 →
57YearsYears 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 2029 — from 0.62 in 2024 to a central estimate of 0.42 (95% range 0.00–0.99). A 5-year backtest shows a typical error of ±31.1%, with 100% of held-out values landing inside the 95% band.

-32%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 →
0.42Projected 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 →
0.00–0.9995% 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 →
±31.1%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 2029 — from 0.62 in 2024 to a central estimate of 0.42 (95% range 0.00–0.99). A 5-year backtest shows a typical error of ±31.1%, with 100% 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 →
20250.470.001.0
20260.460.001.0
20270.450.001.0
20280.430.001.0
20290.420.000.99

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-DAKOTA192024
ScrantonIOWA171999
TrippSOUTH-DAKOTA151988
ErieMINNESOTA101997
BowesmontNORTH-DAKOTA101995
BroadlandSOUTH-DAKOTA101969
LennoxSOUTH-DAKOTA82024
OkleeMINNESOTA71993
ChokioMINNESOTA62024
SpartaNEBRASKA62019
CooperstownNORTH-DAKOTA62003
TitonkaIOWA51981
Eagle CreekNEBRASKA51975
NilesNORTH-DAKOTA52021
LoraineNORTH-DAKOTA52019
AbercrombieNORTH-DAKOTA52012
GeddesSOUTH-DAKOTA41970
PantherIOWA32022
HartlandMINNESOTA32017
RedstoneMONTANA32021
FormanNORTH-DAKOTA31992
Danzig 2NORTH-DAKOTA32023
WashingtonIOWA22024
KanawhaIOWA21986
ClareIOWA22009

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