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

MacGillivray's Warbler In Badlands and Prairies

All regionsBadlands and PrairiesForest birds

MacGillivray's Warbler in Badlands and Prairies has surged: up 204% on the route-weighted index since 1978.

+204%Since 1978TrendPercent 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 →
17Routes 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 →
47YearsYears 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 increasecomputed 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 →

MacGillivray's Warbler has surged in Badlands and Prairies: up 204% on the route-weighted index since 1978.

MacGillivray's Warbler In Badlands and Prairies Population Forecast

If the recent trend holds, MacGillivray's Warbler in Badlands and Prairies is projected to stay roughly flat through 2029, near 0.28 (95% range 0.07–0.48). A 5-year backtest shows a typical error of ±95.7%, with 80% of held-out values landing inside the 95% band.

+7%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 →
0.28Projected 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 →
0.07–0.4895% 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 →
±95.7%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, MacGillivray's Warbler in Badlands and Prairies is projected to stay roughly flat through 2029, near 0.28 (95% range 0.07–0.48). A 5-year backtest shows a typical error of ±95.7%, with 80% of held-out values landing inside the 95% band.19762029
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 →
20250.270.060.47
20260.270.070.47
20270.270.070.47
20280.270.070.47
20290.280.070.48

Routes In Badlands and Prairies

Routes recording MacGillivray's Warbler 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 →
MoskeeWYOMING112001
Moskee 3WYOMING82024
Moskee 2WYOMING52019
Long DrawSOUTH-DAKOTA42024
SundanceWYOMING42024
RochfordSOUTH-DAKOTA32018
Maynard CouleeMONTANA22024
EnglewoodSOUTH-DAKOTA22021
NorbeckSOUTH-DAKOTA22000
Two DotMONTANA11976
Roubaix LkSOUTH-DAKOTA11981
Hill CitySOUTH-DAKOTA12013
Black FoxSOUTH-DAKOTA12017
Silver CitySOUTH-DAKOTA12002
HazelrodtSOUTH-DAKOTA12001
Lightning CrSOUTH-DAKOTA12009
DaytonWYOMING11981

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