Species · BBS 2025 Release · 1966–2024

Blue-gray Gnatcatcher

PolioptilidaeForest birdsPolioptila caerulea

Blue-gray Gnatcatcher has surged: up 150% on the route-weighted index since 1968.

About the Blue-gray Gnatcatcher

The Blue-gray Gnatcatcher (Polioptila caerulea) is a North American member of the Gnatcatchers (Polioptilidae). In this analysis it is grouped with the forest birds.

Size
4–5 in long (10–13 cm) — a tiny, long-tailed songbird (typical for the family)
Habitat
Woodlands and forest edges, including wooded suburbs and parks.
Diet
Insects and spiders gleaned from foliage and bark, with seeds and berries in season.
Range
Recorded on 2,535 Breeding Bird Survey routes across 45 states, most concentrated in the Appalachian Mountains.
Family
Polioptilidae · Forest birds

Notable Blue-gray Gnatcatcher TrendsNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

Blue-gray Gnatcatcher has surged in surveyed states: up 150% on the route-weighted index since 1968.

Blue-gray Gnatcatcher Population Forecast

If the recent trend holds, Blue-gray Gnatcatcher is projected to rise about 20% by 2029 — from 2.9 in 2024 to a central estimate of 3.4 (95% range 2.9–3.9). A 5-year backtest shows a typical error of ±14.5%, with 40% of held-out values landing inside the 95% band.

If the recent trend holds, Blue-gray Gnatcatcher is projected to rise about 20% by 2029 — from 2.9 in 2024 to a central estimate of 3.4 (95% range 2.9–3.9). A 5-year backtest shows a typical error of ±14.5%, with 40% of held-out values landing inside the 95% band.19662029
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 →
20253.32.83.8
20263.32.83.8
20273.42.93.8
20283.42.93.9
20293.42.93.9

Where the Blue-gray Gnatcatcher Is Detected

BBS routes recording Blue-gray Gnatcatcher, sized by most recent count.

Blue-gray Gnatcatcher Population Trend by State

Blue-gray Gnatcatcher population trend by state.
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 →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
Alabama+440%1968108
Arizona+2%197039
Arkansas+79%196961
California+532%1970145
Colorado+647%197368
Connecticut11×197720
Delaware15×196916
Florida+201%1968104
Georgia+402%1968108
Idaho-24%19895
Illinois18×196897
Indiana+96%196859
Iowa+28%198018
Kansas+254%196943
Kentucky+58%196864
Louisiana+328%196983
Maineinsufficient datan/a5
Maryland+660%196876
Massachusetts14×197824
Michigan+650%197352
Minnesota+197%197623
Mississippi+546%196872
Missouri+272%196986
Nebraska+7%19936
Nevada+160%198827
New Hampshire+141%197711
New Jersey23×197036
New Mexico+257%197133
New York+113%196861
North Carolina+697%1968111
Ohio+101%196883
Oklahoma+61%196964
Oregon-45%199911
Pennsylvania+204%1968124
Rhode Island+564%19915
South Carolina+297%196851
South Dakotainsufficient datan/a1
Tennessee+189%196855
Texas+222%1969165
Utah+384%198580
Vermont-32%19828
Virginia+153%196885
West Virginia-47%196861
Wisconsin15×197465
Wyoming-33%199016

Blue-gray Gnatcatcher Population Trend by Region

Bird Conservation Regions are the ecological unit for trends.

Blue-gray Gnatcatcher population trend by Bird Conservation Region.
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 →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
Northern Pacific Rainforest-47%197019
Great Basin+321%197164
Northern Rockies+129%198022
Boreal Hardwood Transition+102%198917
Lower Great Lakes / St. Lawrence Plain+3%196856
Atlantic Northern Forest+75%197726
Sierra Nevada+5%197421
Southern Rockies / Colorado Plateau+529%1970155
Shortgrass Prairie+3%198413
Central Mixed Grass Prairie+52%196966
Edwards Plateau15×197318
Oaks and Prairies+165%196969
Eastern Tallgrass Prairie+294%1968231
Prairie Hardwood Transition24×1969136
Central Hardwoods+123%1968165
West Gulf Coastal Plain / Ouachitas+103%1969109
Mississippi Alluvial Valley+120%196864
Southeastern Coastal Plain+440%1968343
Appalachian Mountains+78%1968374
Piedmont+465%1968166
New England / Mid-Atlantic Coast+630%1968146
Peninsular Florida+322%196859
Coastal California+860%197173
Sonoran and Mojave Deserts+13%197430
Sierra Madre Occidental+64%197523
Chihuahuan Desert-41%197021
Tamaulipan Brushlands+195%197221
Gulf Coastal Prairie-84%197121

Blue-gray Gnatcatcher Conservation Status

Our route-weighted index shows it up about 150% since 1968.

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22. Trend is a route-weighted relative-abundance index, not an absolute population.