Warbling Vireo
Warbling Vireo has surged: up 174% on the route-weighted index since 1968.
About the Warbling Vireo
The Warbling Vireo (Vireo gilvus) is a North American member of the Vireos (Vireonidae). In this analysis it is grouped with the forest birds.
- Size
- 4.5–6 in long (11–15 cm) — a small, deliberate 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 2,530 Breeding Bird Survey routes across 46 states, most concentrated in the Eastern Tallgrass Prairie.
- Family
- Vireonidae · Forest birds
Notable Warbling Vireo Trends
Warbling Vireo has surged in surveyed states: up 174% on the route-weighted index since 1968.
Warbling Vireo Population Forecast
If the recent trend holds, Warbling Vireo is projected to rise about 12% by 2029 — from 3.2 in 2024 to a central estimate of 3.6 (95% range 3.1–4.0). A 5-year backtest shows a typical error of ±8.1%, with 100% of held-out values landing inside the 95% band.
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 3.4 | 3.0 | 3.9 |
| 2026 | 3.5 | 3.0 | 3.9 |
| 2027 | 3.5 | 3.1 | 3.9 |
| 2028 | 3.5 | 3.1 | 4.0 |
| 2029 | 3.6 | 3.1 | 4.0 |
Where the Warbling Vireo Is Detected
BBS routes recording Warbling Vireo, sized by most recent count.
Warbling Vireo Population Trend by State
| Alabama | insufficient data | n/a | 5 |
| Alaska | +778% | 1993 | 11 |
| Arizona | 14× | 1974 | 28 |
| Arkansas | +193% | 1969 | 29 |
| California | +34% | 1970 | 182 |
| Colorado | +332% | 1970 | 109 |
| Connecticut | +187% | 1968 | 20 |
| Delaware | -41% | 1971 | 8 |
| Idaho | +135% | 1972 | 56 |
| Illinois | +155% | 1968 | 104 |
| Indiana | +95% | 1968 | 68 |
| Iowa | +201% | 1969 | 39 |
| Kansas | +134% | 1969 | 63 |
| Kentucky | +145% | 1968 | 46 |
| Louisiana | -48% | 1970 | 10 |
| Maine | +133% | 1969 | 65 |
| Maryland | +233% | 1968 | 47 |
| Massachusetts | +589% | 1968 | 28 |
| Michigan | +9% | 1968 | 95 |
| Minnesota | +1% | 1969 | 85 |
| Mississippi | -41% | 1969 | 13 |
| Missouri | +18% | 1969 | 80 |
| Montana | +121% | 1970 | 83 |
| Nebraska | +223% | 1969 | 65 |
| Nevada | -6% | 1979 | 26 |
| New Hampshire | +19% | 1968 | 25 |
| New Jersey | 13× | 1968 | 25 |
| New Mexico | +237% | 1970 | 29 |
| New York | +275% | 1968 | 123 |
| North Carolina | -26% | 1997 | 11 |
| North Dakota | +333% | 1969 | 50 |
| Ohio | -11% | 1968 | 87 |
| Oklahoma | +3% | 1969 | 50 |
| Oregon | +70% | 1970 | 113 |
| Pennsylvania | +181% | 1968 | 114 |
| Rhode Island | +390% | 1989 | 4 |
| South Dakota | +172% | 1969 | 57 |
| Tennessee | +398% | 1968 | 27 |
| Texas | -64% | 1971 | 18 |
| Utah | +808% | 1972 | 64 |
| Vermont | +125% | 1968 | 26 |
| Virginia | +59% | 1969 | 32 |
| Washington | +106% | 1970 | 88 |
| West Virginia | -78% | 1968 | 53 |
| Wisconsin | -16% | 1968 | 94 |
| Wyoming | +53% | 1970 | 75 |
Warbling Vireo Population Trend by Region
Bird Conservation Regions are the ecological unit for trends.
| Northern Pacific Rainforest | +13% | 1970 | 137 |
| Great Basin | +221% | 1970 | 149 |
| Northern Rockies | +85% | 1970 | 191 |
| Prairie Potholes | +308% | 1969 | 111 |
| Boreal Hardwood Transition | -74% | 1968 | 104 |
| Lower Great Lakes / St. Lawrence Plain | +197% | 1968 | 85 |
| Atlantic Northern Forest | +93% | 1968 | 139 |
| Sierra Nevada | +97% | 1971 | 40 |
| Southern Rockies / Colorado Plateau | +404% | 1970 | 165 |
| Badlands and Prairies | +55% | 1969 | 81 |
| Shortgrass Prairie | +82% | 1973 | 40 |
| Central Mixed Grass Prairie | +162% | 1969 | 96 |
| Oaks and Prairies | -32% | 1970 | 16 |
| Eastern Tallgrass Prairie | +153% | 1968 | 271 |
| Prairie Hardwood Transition | +15% | 1968 | 159 |
| Central Hardwoods | +129% | 1968 | 129 |
| West Gulf Coastal Plain / Ouachitas | -7% | 1970 | 35 |
| Mississippi Alluvial Valley | +7% | 1968 | 25 |
| Southeastern Coastal Plain | +0% | 1969 | 26 |
| Appalachian Mountains | +3% | 1968 | 256 |
| Piedmont | +198% | 1968 | 56 |
| New England / Mid-Atlantic Coast | +263% | 1968 | 96 |
| Coastal California | +118% | 1970 | 79 |
| Sonoran and Mojave Deserts | -51% | 1980 | 9 |
| Sierra Madre Occidental | +230% | 1974 | 26 |
| Chihuahuan Desert | +78% | 1982 | 7 |
Warbling Vireo Conservation Status
Our route-weighted index shows it up about 174% 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.