BirdAnalyst
Species · BCR 29 · BBS 2025 Release · 1966–2024

Purple Martin In Piedmont

All regionsPiedmontAerial insectivores

Purple Martin in Piedmont has declined: down 36% on the route-weighted index since 1968.

-36%Since 1968TrendPercent 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 →
167Routes 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 Piedmont. See the full index history below.

Purple Martin In Piedmont Population Forecast

If the recent trend holds, Purple Martin in Piedmont is projected to rise about 14% by 2029 — from 5.3 in 2024 to a central estimate of 6.1 (95% range 0.67–11). A 5-year backtest shows a typical error of ±55.5%, with 100% of held-out values landing inside the 95% band.

+14%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 →
6.1Projected 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 →
0.67–1195% 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 →
±55.5%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 Piedmont is projected to rise about 14% by 2029 — from 5.3 in 2024 to a central estimate of 6.1 (95% range 0.67–11). A 5-year backtest shows a typical error of ±55.5%, 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 →
20256.20.7612
20266.10.7412
20276.10.7211
20286.10.6911
20296.10.6711

Routes In Piedmont

Routes recording Purple Martin in Piedmont.
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 →
BlacksburgSOUTH-CAROLINA3122013
MetasvilleGEORGIA652000
Little MtnSOUTH-CAROLINA581988
ProsperitySOUTH-CAROLINA532024
WedoweeALABAMA352023
RutledgeGEORGIA332024
LeolaPENNSYLVANIA332024
AthensGEORGIA312024
Barton CreekSOUTH-CAROLINA292022
Nixburg 2ALABAMA272024
JordanNORTH-CAROLINA242022
Liberty City 2ALABAMA222024
HiramGEORGIA222018
CandlerGEORGIA202024
MadonnaMARYLAND192022
IjamsvilleMARYLAND182024
TaylorstownVIRGINIA182010
OakboroNORTH-CAROLINA172024
ClimaxNORTH-CAROLINA162024
PendletonSOUTH-CAROLINA161976
FairplayGEORGIA151990
Rock BranchGEORGIA152024
WacoNORTH-CAROLINA152019
FlayNORTH-CAROLINA152024
Salem XrdSOUTH-CAROLINA152017

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