Canada Warbler
Canada Warbler has fallen sharply: down 60% on the route-weighted index since 1968.
About the Canada Warbler
The Canada Warbler (Cardellina canadensis) is a North American member of the Wood-Warblers (Parulidae). In this analysis it is grouped with the forest birds.
- Size
- 4.5–5.5 in long (11–14 cm) — a small, active 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 491 Breeding Bird Survey routes across 20 states, most concentrated in the Atlantic Northern Forest.
- Family
- Parulidae · Forest birds
Notable Canada Warbler Trends
Canada Warbler has fallen sharply in surveyed states: down 60% on the route-weighted index since 1968.
Canada Warbler Population Forecast
If the recent trend holds, Canada Warbler is projected to fall about 50% by 2029 — from 0.09 in 2024 to a central estimate of 0.04 (95% range 0.00–0.09). A 5-year backtest shows a typical error of ±43%, with 80% of held-out values landing inside the 95% band.
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 0.06 | 0.01 | 0.10 |
| 2026 | 0.05 | 0.00 | 0.10 |
| 2027 | 0.05 | 0.00 | 0.10 |
| 2028 | 0.05 | 0.00 | 0.10 |
| 2029 | 0.04 | 0.00 | 0.09 |
Where the Canada Warbler Is Detected
BBS routes recording Canada Warbler, sized by most recent count.
Canada Warbler Population Trend by State
| Connecticut | -85% | 1968 | 14 |
| Georgia | insufficient data | n/a | 1 |
| Indiana | insufficient data | n/a | 1 |
| Maine | -85% | 1968 | 73 |
| Maryland | -49% | 1968 | 7 |
| Massachusetts | -72% | 1969 | 16 |
| Michigan | -5% | 1969 | 53 |
| Minnesota | +156% | 1969 | 32 |
| New Hampshire | -86% | 1968 | 26 |
| New Jersey | insufficient data | n/a | 6 |
| New York | -62% | 1968 | 80 |
| North Carolina | +6% | 1976 | 13 |
| Ohio | insufficient data | n/a | 1 |
| Pennsylvania | +46% | 1968 | 60 |
| Rhode Island | -77% | 1969 | 4 |
| Tennessee | +135% | 1991 | 4 |
| Vermont | -80% | 1968 | 22 |
| Virginia | +266% | 1977 | 15 |
| West Virginia | 12× | 1978 | 18 |
| Wisconsin | +14% | 1968 | 45 |
Canada Warbler Population Trend by Region
Bird Conservation Regions are the ecological unit for trends.
| Boreal Hardwood Transition | +94% | 1968 | 101 |
| Lower Great Lakes / St. Lawrence Plain | -77% | 1968 | 30 |
| Atlantic Northern Forest | -80% | 1968 | 150 |
| Prairie Hardwood Transition | -65% | 1972 | 30 |
| Appalachian Mountains | +73% | 1968 | 145 |
| New England / Mid-Atlantic Coast | -90% | 1968 | 34 |
Canada Warbler Conservation Status
Our route-weighted index shows it down about 60% 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.