BirdAnalyst
Species · BCR 17 · BBS 2025 Release · 1966–2024

Black Tern In Badlands and Prairies

All regionsBadlands and PrairiesWetland birds

Black Tern in Badlands and Prairies has fallen sharply: down 63% on the route-weighted index since 1969.

-63%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 →
15Routes 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 →
21YearsYears 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 →

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 →

Black Tern has fallen sharply in Badlands and Prairies: down 62% on the route-weighted index since 1969.

Black Tern In Badlands and Prairies Population Forecast

If the recent trend holds, Black Tern in Badlands and Prairies is projected to fall about 100% by 2024 — from 0.22 in 2019 to a central estimate of 0.00 (95% range 0.00–0.41). A 5-year backtest shows a typical error of ±322%, with 60% of held-out values landing inside the 95% band.

-100%Change by 2024TrendPercent 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 2024 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.4195% 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 →
±322%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, Black Tern in Badlands and Prairies is projected to fall about 100% by 2024 — from 0.22 in 2019 to a central estimate of 0.00 (95% range 0.00–0.41). A 5-year backtest shows a typical error of ±322%, with 60% of held-out values landing inside the 95% band.19672024
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 →
20200.010.000.42
20210.010.000.42
20220.010.000.41
20230.000.000.41
20240.000.000.41

Routes In Badlands and Prairies

Routes recording Black Tern in Badlands and Prairies.
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 →
LacreekSOUTH-DAKOTA132019
CottonwoodSOUTH-DAKOTA92009
OwankaSOUTH-DAKOTA72014
Ft YatesNORTH-DAKOTA41969
BowmanNORTH-DAKOTA42014
Glen UllinNORTH-DAKOTA42015
Dunn CenterNORTH-DAKOTA32019
HardingSOUTH-DAKOTA31982
LaplantSOUTH-DAKOTA21978
GorhamNORTH-DAKOTA11992
CarsonNORTH-DAKOTA12019
ChamberlainSOUTH-DAKOTA11968
Ft ThompsonSOUTH-DAKOTA11990
PioneerSOUTH-DAKOTA11995
S. PioneerSOUTH-DAKOTA12002

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