BirdAnalyst
Guild · Michigan · BBS 2026 Release · 1966–2025

Generalists In Michigan

All statesMichigan

11 species in this guild. As a group they are -60%Guild trendA mean-index aggregate across the species in this group — the structural direction of the guild, with individual-species noise smoothed out.Full methodology → since 1968.

Guild SignalsNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

guild collapsecomputed 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 →

Generalists as a group have fallen sharply in Michigan, down 60% since 1968.

Generalists In Michigan Population Forecast

If the recent trend holds, Generalists in Michigan is projected to fall about 40% by 2030 — from 14 in 2025 to a central estimate of 8.3 (95% range 2.5–14). A 5-year backtest shows a typical error of ±31.6%, with 100% of held-out values landing inside the 95% band.

-40%Change 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 →
8.3Projected 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 →
2.5–1495% 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 →
±31.6%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, Generalists in Michigan is projected to fall about 40% by 2030 — from 14 in 2025 to a central estimate of 8.3 (95% range 2.5–14). A 5-year backtest shows a typical error of ±31.6%, with 100% of held-out values landing inside the 95% band.19662030
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 →
20269.84.016
20279.43.615
20289.13.315
20298.72.915
20308.32.514

Member Species In Michigan

Generalists species in Michigan.
TrendPercent 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 →
Brewer's BlackbirdIcteridae-87%
Northern MockingbirdMimidae-82%
House SparrowPasseridae-76%
Common GrackleIcteridae-75%
Brown-headed CowbirdIcteridae-63%
European StarlingSturnidae-54%
Rock PigeonColumbidae-31%
American CrowCorvidae+19%
Mourning DoveColumbidae+29%
Common RavenCorvidae+51%
House FinchFringillidae37×

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