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

Philadelphia Vireo Population Trend in Michigan

All statesForest birds

Philadelphia Vireo in Michigan has surged: up 131% on the route-weighted index since 1993.

+131%Since 1993TrendPercent 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 →
19YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Philadelphia Vireo Trends in MichiganNotable 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 →

Philadelphia Vireo has surged in Michigan: up 131% on the route-weighted index since 1993.

Philadelphia Vireo Population Forecast in Michigan

If the recent trend holds, Philadelphia Vireo in Michigan is projected to stay roughly flat through 2027, near 0.07 (95% range 0.00–0.14). A 5-year backtest shows a typical error of ±55.9%, with 80% of held-out values landing inside the 95% band.

n/aChange by 2027TrendPercent 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 →
0.07Projected 2027 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.1495% 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 →
±55.9%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, Philadelphia Vireo in Michigan is projected to stay roughly flat through 2027, near 0.07 (95% range 0.00–0.14). A 5-year backtest shows a typical error of ±55.9%, with 80% of held-out values landing inside the 95% band.19882027
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 →
20230.070.000.14
20240.070.000.14
20250.070.000.14
20260.070.000.14
20270.070.000.14

Philadelphia Vireo Survey Routes in Michigan

Routes recording Philadelphia Vireo in Michigan.
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 →
Ontonagon420192012
Ishpeming420191990
Crystal Fls319881988
Bergland220222009
Imp Lake220122000
Herman120132013
Hiawatha Nf119941994
Pickford120112011
Sidnaw120131996
Cunard120161990
Cluster Lakes120072007
Lake City120012001

Philadelphia Vireo Population Trend in Other States

alabamamaineminnesotanew-hampshirenew-yorknorth-dakotavermontwisconsin

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