Blue Grosbeak
Blue Grosbeak has risen sharply: up 64% on the route-weighted index since 1968.
About the Blue Grosbeak
The Blue Grosbeak (Passerina caerulea) is a North American member of the Cardinals & Grosbeaks (Cardinalidae). In this analysis it is grouped with the forest birds.
- Size
- 4.5–8.5 in long (12–22 cm) — a medium 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 2,079 Breeding Bird Survey routes across 38 states, most concentrated in the Southeastern Coastal Plain.
- Family
- Cardinalidae · Forest birds
Notable Blue Grosbeak Trends
Blue Grosbeak has risen sharply in surveyed states: up 64% on the route-weighted index since 1968.
Blue Grosbeak Population Forecast
If the recent trend holds, Blue Grosbeak is projected to stay roughly flat through 2029, near 2.6 (95% range 2.2–2.9). A 5-year backtest shows a typical error of ±3.2%, with 100% of held-out values landing inside the 95% band.
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 2.5 | 2.2 | 2.8 |
| 2026 | 2.5 | 2.2 | 2.8 |
| 2027 | 2.5 | 2.2 | 2.9 |
| 2028 | 2.5 | 2.2 | 2.9 |
| 2029 | 2.6 | 2.2 | 2.9 |
Where the Blue Grosbeak Is Detected
BBS routes recording Blue Grosbeak, sized by most recent count.
Blue Grosbeak Population Trend by State
| Alabama | +19% | 1968 | 108 |
| Arizona | +65% | 1970 | 44 |
| Arkansas | +57% | 1969 | 61 |
| California | +16% | 1971 | 71 |
| Colorado | +74% | 1971 | 86 |
| Delaware | +564% | 1968 | 17 |
| Florida | +90% | 1968 | 74 |
| Georgia | -9% | 1968 | 109 |
| Idaho | insufficient data | n/a | 2 |
| Illinois | 46× | 1968 | 77 |
| Indiana | 33× | 1973 | 44 |
| Iowa | +344% | 1970 | 17 |
| Kansas | +181% | 1969 | 65 |
| Kentucky | 28× | 1968 | 56 |
| Louisiana | +290% | 1969 | 84 |
| Maryland | +209% | 1968 | 69 |
| Minnesota | -19% | 1977 | 10 |
| Mississippi | +61% | 1968 | 74 |
| Missouri | +80% | 1969 | 90 |
| Montana | insufficient data | n/a | 1 |
| Nebraska | +269% | 1969 | 70 |
| Nevada | +94% | 1971 | 8 |
| New Jersey | +142% | 1969 | 22 |
| New Mexico | +473% | 1970 | 79 |
| New York | insufficient data | n/a | 1 |
| North Carolina | +50% | 1968 | 101 |
| North Dakota | +146% | 2010 | 8 |
| Ohio | 15× | 1985 | 16 |
| Oklahoma | +71% | 1969 | 70 |
| Pennsylvania | -77% | 1976 | 24 |
| South Carolina | -4% | 1968 | 51 |
| South Dakota | +149% | 1969 | 34 |
| Tennessee | +352% | 1968 | 53 |
| Texas | +85% | 1969 | 232 |
| Utah | +26% | 1979 | 40 |
| Virginia | +104% | 1968 | 74 |
| West Virginia | -28% | 1975 | 22 |
| Wyoming | +149% | 1986 | 15 |
Blue Grosbeak Population Trend by Region
Bird Conservation Regions are the ecological unit for trends.
| Great Basin | -43% | 1971 | 13 |
| Northern Rockies | +333% | 1992 | 11 |
| Prairie Potholes | +148% | 1969 | 31 |
| Southern Rockies / Colorado Plateau | +168% | 1970 | 112 |
| Badlands and Prairies | -8% | 1969 | 35 |
| Shortgrass Prairie | +305% | 1969 | 122 |
| Central Mixed Grass Prairie | +151% | 1969 | 126 |
| Edwards Plateau | +657% | 1969 | 20 |
| Oaks and Prairies | -16% | 1969 | 68 |
| Eastern Tallgrass Prairie | 13× | 1968 | 187 |
| Central Hardwoods | +268% | 1968 | 161 |
| West Gulf Coastal Plain / Ouachitas | +32% | 1969 | 108 |
| Mississippi Alluvial Valley | +845% | 1968 | 66 |
| Southeastern Coastal Plain | +100% | 1968 | 342 |
| Appalachian Mountains | -13% | 1968 | 163 |
| Piedmont | +15% | 1968 | 154 |
| New England / Mid-Atlantic Coast | +213% | 1968 | 92 |
| Peninsular Florida | +90% | 1968 | 30 |
| Coastal California | +63% | 1971 | 53 |
| Sonoran and Mojave Deserts | -45% | 1970 | 31 |
| Sierra Madre Occidental | +25% | 1970 | 28 |
| Chihuahuan Desert | +239% | 1969 | 56 |
| Tamaulipan Brushlands | -21% | 1969 | 28 |
| Gulf Coastal Prairie | +599% | 1975 | 33 |
Blue Grosbeak Conservation Status
Our route-weighted index shows it up about 64% 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.