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

Northern Parula Population Trend in Illinois

All statesForest birds

Northern Parula in Illinois has surged: up 27× on the route-weighted index since 1969.

27×Since 1969
57Routes In State
56Years

Notable Northern Parula Trends in Illinois

long arc increasecomputed index

Northern Parula has surged in Illinois: up 27× on the route-weighted index since 1969.

Northern Parula Population Forecast in Illinois

If the recent trend holds, Northern Parula in Illinois is projected to stay roughly flat through 2029, near 1.2 (95% range 0.83–1.6). A 5-year backtest shows a typical error of ±29.2%, with 40% of held-out values landing inside the 95% band.

-0%Change by 2029
1.2Projected 2029 index
0.83–1.695% range
±29.2%Backtest error
19672029
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected index95% low95% high
20251.10.741.6
20261.20.761.6
20271.20.791.6
20281.20.811.6
20291.20.831.6

Northern Parula Survey Routes in Illinois

Routes recording Northern Parula in Illinois.
Beaverdam Lk1920231970
Bremen1620241969
Sandusky1520231993
Pulaski1420241973
Belknap1320241974
Belleview1020241967
Delwood720241978
York620241999
Royalton420242002
Cave In Rock420241993
St Morgan320221984
Karnak320242003
Athens220242022
Clayton220232009
Grape Creek220242007
Melrose219981973
Jamestown220172005
Beaucoup220241972
Olney220161978
Brownville220242002
Payson120182004
Sheffield120171987
Waynesville120032003
Newark120172009
Gulfport120091981

Northern Parula Population Trend in Other States

alabamaarkansascaliforniaconnecticutdelawarefloridageorgiaindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourinebraskanew-hampshirenew-jerseynew-yorknorth-carolinaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawest-virginiawisconsin

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