Green Heron
Green Heron has fallen sharply: down 67% on the route-weighted index since 1968.
About the Green Heron
The Green Heron (Butorides virescens) is a North American member of the Herons, Egrets & Bitterns (Ardeidae). In this analysis it is grouped with the wetland birds.
- Size
- 12–51 in long (30–130 cm) — a long-legged wader (typical for the family)
- Habitat
- Marshes, ponds, lakeshores and other freshwater wetlands.
- Diet
- Aquatic invertebrates, small fish, frogs and plant matter.
- Range
- Recorded on 2,421 Breeding Bird Survey routes across 43 states, most concentrated in the Appalachian Mountains.
- Family
- Ardeidae · Wetland birds
Notable Green Heron Trends
Green Heron has fallen sharply in surveyed states: down 66% on the route-weighted index since 1968.
Green Heron Population Forecast
If the recent trend holds, Green Heron is projected to fall about 43% by 2029 — from 0.28 in 2024 to a central estimate of 0.16 (95% range 0.04–0.28). A 5-year backtest shows a typical error of ±16.6%, with 100% of held-out values landing inside the 95% band.
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 0.20 | 0.08 | 0.33 |
| 2026 | 0.19 | 0.07 | 0.31 |
| 2027 | 0.18 | 0.06 | 0.30 |
| 2028 | 0.17 | 0.05 | 0.29 |
| 2029 | 0.16 | 0.04 | 0.28 |
Where the Green Heron Is Detected
BBS routes recording Green Heron, sized by most recent count.
Green Heron Population Trend by State
| Alabama | -54% | 1968 | 106 |
| Arizona | -72% | 1982 | 11 |
| Arkansas | -67% | 1969 | 50 |
| California | -10% | 1972 | 93 |
| Connecticut | -46% | 1969 | 17 |
| Delaware | +70% | 1968 | 17 |
| Florida | -64% | 1968 | 117 |
| Georgia | -63% | 1968 | 96 |
| Illinois | -27% | 1968 | 101 |
| Indiana | -66% | 1968 | 61 |
| Iowa | -14% | 1970 | 32 |
| Kansas | -77% | 1969 | 47 |
| Kentucky | -74% | 1968 | 60 |
| Louisiana | -39% | 1969 | 98 |
| Maine | -77% | 1968 | 22 |
| Maryland | -45% | 1968 | 74 |
| Massachusetts | -22% | 1969 | 28 |
| Michigan | +52% | 1968 | 77 |
| Minnesota | -14% | 1969 | 62 |
| Mississippi | +4% | 1968 | 61 |
| Missouri | -50% | 1969 | 84 |
| Nebraska | -68% | 1972 | 19 |
| Nevada | insufficient data | n/a | 1 |
| New Hampshire | -37% | 1968 | 18 |
| New Jersey | -57% | 1968 | 39 |
| New Mexico | -25% | 1993 | 5 |
| New York | -35% | 1968 | 106 |
| North Carolina | -50% | 1968 | 95 |
| North Dakota | insufficient data | n/a | 1 |
| Ohio | -57% | 1968 | 78 |
| Oklahoma | -79% | 1969 | 63 |
| Oregon | -86% | 1971 | 26 |
| Pennsylvania | -54% | 1968 | 123 |
| Rhode Island | -55% | 1972 | 6 |
| South Carolina | -56% | 1968 | 46 |
| South Dakota | +42% | 1974 | 9 |
| Tennessee | -75% | 1968 | 49 |
| Texas | -52% | 1969 | 170 |
| Vermont | -72% | 1970 | 20 |
| Virginia | -62% | 1968 | 66 |
| Washington | -73% | 1978 | 21 |
| West Virginia | -85% | 1968 | 54 |
| Wisconsin | +18% | 1968 | 92 |
Green Heron Population Trend by Region
Bird Conservation Regions are the ecological unit for trends.
| Northern Pacific Rainforest | -79% | 1971 | 60 |
| Great Basin | +87% | 1971 | 8 |
| Prairie Potholes | -38% | 1971 | 36 |
| Boreal Hardwood Transition | -4% | 1968 | 78 |
| Lower Great Lakes / St. Lawrence Plain | -12% | 1968 | 81 |
| Atlantic Northern Forest | -66% | 1968 | 67 |
| Shortgrass Prairie | -88% | 1978 | 9 |
| Central Mixed Grass Prairie | -9% | 1969 | 81 |
| Edwards Plateau | -6% | 1971 | 16 |
| Oaks and Prairies | -49% | 1969 | 73 |
| Eastern Tallgrass Prairie | -55% | 1968 | 242 |
| Prairie Hardwood Transition | +38% | 1968 | 154 |
| Central Hardwoods | -78% | 1968 | 151 |
| West Gulf Coastal Plain / Ouachitas | -83% | 1969 | 100 |
| Mississippi Alluvial Valley | +19% | 1969 | 70 |
| Southeastern Coastal Plain | -52% | 1968 | 317 |
| Appalachian Mountains | -65% | 1968 | 335 |
| Piedmont | -50% | 1968 | 150 |
| New England / Mid-Atlantic Coast | -47% | 1968 | 154 |
| Peninsular Florida | -68% | 1968 | 79 |
| Coastal California | +38% | 1972 | 63 |
| Sonoran and Mojave Deserts | -16% | 1979 | 13 |
| Chihuahuan Desert | -60% | 1995 | 6 |
| Tamaulipan Brushlands | -3% | 1970 | 23 |
| Gulf Coastal Prairie | -23% | 1969 | 46 |
Green Heron Conservation Status
Our route-weighted index shows it down about 66% 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.