BirdAnalyst
Species · Minnesota · BBS 2025 Release · 1966–2024

Purple Martin Population Trend in Minnesota

All statesAerial insectivores

Purple Martin in Minnesota has collapsed: down 83% on the route-weighted index since 1969.

-83%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 →
68Routes In StateSurvey 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 Purple Martin Trends in MinnesotaNotable 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 declinecomputed 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 →

Purple Martin has collapsed in Minnesota: down 83% on the route-weighted index since 1969.

Purple Martin Population Forecast in Minnesota

If the recent trend holds, Purple Martin in Minnesota is projected to fall about 100% by 2029 — from 1.1 in 2024 to a central estimate of 0.00 (95% range 0.00–1.6). A 5-year backtest shows a typical error of ±218.5%, with 60% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–1.695% 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 →
±218.5%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 Minnesota is projected to fall about 100% by 2029 — from 1.1 in 2024 to a central estimate of 0.00 (95% range 0.00–1.6). A 5-year backtest shows a typical error of ±218.5%, with 60% 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 →
20250.000.001.6
20260.000.001.6
20270.000.001.6
20280.000.001.6
20290.000.001.6

Purple Martin Survey Routes in Minnesota

Routes recording Purple Martin in Minnesota.
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 →
Edwards3620241973
Bena3519771967
Bemidji1219801967
Whitewater 21120192014
Erie1019971986
Oklee719931969
St Stephen620161967
Chokio620241978
Island Lake619881969
New London620241995
Glenwood620191993
Nebish619951982
Money Creek520111969
Backus519971968
Evergreen520071967
Princeton420231970
Lude420011978
Brook Park420212008
Hartland320171967
Cromwell320241969
Wigwam Bay320231967
Le Center320081999
Mcgregor320221993
Ashby320211997
Chatfield219881973

Purple Martin Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganmississippimissourimontananebraskanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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