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

Purple Martin Population Trend in Connecticut

All statesAerial insectivores

Purple Martin in Connecticut has edged down: down 22% on the route-weighted index since 1973.

-22%Since 1973TrendPercent 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 →
12Routes 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 →
23YearsYears 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 ConnecticutNotable 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 Connecticut. See the full index history below.

Purple Martin Population Forecast in Connecticut

If the recent trend holds, Purple Martin in Connecticut is projected to rise about 240% by 2029 — from 0.11 in 2024 to a central estimate of 0.38 (95% range 0.00–0.86). A 5-year backtest shows a typical error of ±173%, with 100% of held-out values landing inside the 95% band.

+240%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 →
0.38Projected 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 →
0.00–0.8695% 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 →
±173%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 Connecticut is projected to rise about 240% by 2029 — from 0.11 in 2024 to a central estimate of 0.38 (95% range 0.00–0.86). A 5-year backtest shows a typical error of ±173%, with 100% of held-out values landing inside the 95% band.19662029
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 →
20250.370.000.85
20260.370.000.85
20270.370.000.86
20280.370.000.86
20290.380.000.86

Purple Martin Survey Routes in Connecticut

Routes recording Purple Martin in Connecticut.
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 →
Woodstock520052005
Sherman520191976
Danbury320221976
Southington219971997
Mystic120221981
Buckingham119981966
Uncasville120122012
Westbrook120231978
Willimantic119911991
No Woodbury119791971
Warren119731973
Mid Haddam120241977

Purple Martin Population Trend in Other States

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

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