State · BBS 2025 Release · 1966–2024

Illinois Breeding Birds

184 species recorded across 105 survey routes, 1966 to 2024. Browse by family or guild below.

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

Western Meadowlark has collapsed in Illinois: down 98% on the route-weighted index since 1968.

Loggerhead Shrike has collapsed in Illinois: down 97% on the route-weighted index since 1968.

How Bird Guilds Are Faring in IllinoisGuild trendA mean-index aggregate across the species in this group — the structural direction of the guild, with individual-species noise smoothed out.Full methodology →

Illinois Bird Survey Routes

Browse Illinois Birds By FamilyTrendPercent 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 →

Each species links to its trend in Illinois.

Osprey Pandionidae

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