BirdAnalyst
Species · BCR 11 · BBS 2026 Release · 1966–2025

Common Tern In Prairie Potholes

All regionsPrairie PotholesWetland birds

Common Tern in Prairie Potholes has increased: up 38% on the route-weighted index since 1980.

+38%Since 1980TrendPercent 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 →
25Routes 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 →
41YearsYears 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 Common Tern in Prairie Potholes. See the full index history below.

Common Tern In Prairie Potholes Population Forecast

If the recent trend holds, Common Tern in Prairie Potholes is projected to stay roughly flat through 2030, near 0.22 (95% range 0.00–0.47). A 5-year backtest shows a typical error of ±299.8%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2030TrendPercent 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 →
0.22Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.4795% 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 →
±299.8%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, Common Tern in Prairie Potholes is projected to stay roughly flat through 2030, near 0.22 (95% range 0.00–0.47). A 5-year backtest shows a typical error of ±299.8%, with 100% of held-out values landing inside the 95% band.19712030
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 →
20260.210.000.45
20270.210.000.46
20280.210.000.46
20290.220.000.46
20300.220.000.47

Routes In Prairie Potholes

Routes recording Common Tern 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 →
Horsehead LkNORTH-DAKOTA122024
EmeradoNORTH-DAKOTA81997
BraddockNORTH-DAKOTA81989
CourtlandMINNESOTA31991
BadgerMINNESOTA31990
Ester LakeMONTANA32016
Great FallsMONTANA22003
Lake GeorgeNORTH-DAKOTA22004
NilesNORTH-DAKOTA21993
Douglas CrkNORTH-DAKOTA22018
MontpelierNORTH-DAKOTA22025
VeblenSOUTH-DAKOTA21973
ChokioMINNESOTA11987
VirgelleMONTANA11990
ClevelandMONTANA12013
ChinookMONTANA12018
DanzigNORTH-DAKOTA12014
BuchananNORTH-DAKOTA12015
ReganNORTH-DAKOTA12025
StanleyNORTH-DAKOTA11992
Wild RoseNORTH-DAKOTA12023
Powers LakeNORTH-DAKOTA12024
ParshallNORTH-DAKOTA11993
Sheyenne LkNORTH-DAKOTA12009
Turtle MtnsNORTH-DAKOTA12004

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.