When do prothonotary warblers arrive in Ontario?
The Prothonotary Warbler is a summer breeder in Ontario — here is when to expect it, when it leaves, and how to be ready.
Prothonotary Warbler timing in Ontario
- Arrives
- Around April
- Leaves
- By July
- Status here
- Summer breeder
- Nesting season
- May–June
- Present roughly
- April–July
In Ontario, prothonotary warblers are present through the warm months, arriving around April and heading south again by July. Extreme southwest; endangered in Canada.
These windows are set by latitude: Ontario sits in the northern part of this species' range, so timing here runs later than the continental average — the season starts later this far north and the birds wait for it. In any given year, weather can move the first arrivals by a week or two either way.
Month by month in this state
Highlighted months are when prothonotary warblers are expected in Ontario. The edges of the window are the interesting weeks — first arrivals and last departures vary most from year to year.
Getting ready before they arrive
The week before April is the time to act. Have feeders cleaned, filled and out by early April — the first prothonotary warblers into Ontario are scouting for reliable food, and a station that's ready early gets added to their route.
Prothonotary warblers nest in cavities, so boxes need to be up and cleaned before arrival — a box mounted after they've claimed territories will usually sit empty until next year. Prothonotary Warbler nest box dimensions and mounting →
Once nesting begins around May, adults switch to protein-rich food for their young and visits to feeders become quick and purposeful. Expect the busiest activity at dawn.
What prothonotary warblers eat while they're here
- Caterpillars, beetles, mayflies and snails
The only eastern warbler that nests in cavities — it readily takes small nest boxes over water.
Full Prothonotary Warbler diet guide → · Best feeder for prothonotary warblers →
Native plants that hold prothonotary warblers in Ontario
Food keeps a migrant for a day; habitat keeps it for the season. These Ontario-native plants are known to attract prothonotary warblers:
Insects, seeds and cavities.
Fat-rich red fall fruit taken by thrushes, bluebirds and woodpeckers.
Early-summer berries arrive exactly when nestlings are being fed.
Acorns plus hundreds of caterpillar species for nestling food.
Drought-hardy prairie oak with large acorns and a heavy insect load.
Summer fruit and one of the top caterpillar host trees.
Late-summer berry clusters taken by over 40 bird species.
Blue-black fall fruit and dense nesting cover.
Keep exploring
Frequently asked
When do prothonotary warblers arrive in Ontario?
prothonotary warblers typically arrive in Ontario around April, with nesting underway by May. Timing can shift a week or two with the weather in any given year.
When do prothonotary warblers leave Ontario?
Most prothonotary warblers have left Ontario by July. They spend the winter farther south and return the following spring.
Do prothonotary warblers stay in Ontario all year?
No — in Ontario the Prothonotary Warbler is a summer breeder, present roughly April–July. Outside that window it is rarely seen in the state.
What should I put out before prothonotary warblers arrive in Ontario?
Have feeders up and clean by early April — first arrivals scout reliable food sources. Good offerings for this species: caterpillars, beetles, mayflies and snails.
Sources
- Prothonotary Warbler — All About Birds, Cornell Lab of Ornithology
- Prothonotary Warbler life history — Cornell Lab of Ornithology
- Prothonotary Warbler — Audubon Guide to North American Birds
- NestWatch nest box plans and species requirements — Cornell Lab
- eBird region overview and bar charts — Ontario
- Plant Hardiness Zones of Canada — Natural Resources Canada
- Audubon Native Plants Database
- Ontario Breeding Bird Atlas — Birds Canada
Timing reflects typical patterns for the region as a whole; local dates vary with elevation and year. Check the linked eBird bar charts for your county.