Data stories
Questions about monarchs, answered with data
How many monarchs are left? Where do they breed? What does the wind have to do with it? Each story starts with a question and answers it with real numbers from scientists, governments and thousands of volunteers.
Danaus plexippus winter cluster
Story 01 · PopulationTwo populations, thirty wintersThe eastern monarchs that winter in Mexico and the western monarchs on the California coast, counted every winter since the 1990s.
Story 02 · For all agesHow much forest do they fill?Each winter scientists measure how much Mexican forest the monarchs cover. Fill the forest yourself, one square at a time.
Story 03 · MapWhere monarchs breed in CanadaEggs, caterpillars and chrysalises reported across the provinces. Southern Ontario is the nursery.
Story 04 · MapWho is helping?Thousands of habitat projects across the United States, county by county, from the Monarch Conservation Database.
Story 05 · TimelineThree countries, three answersMexico protects the winter forests, Canada lists monarchs as endangered, and the United States is still deciding.
Story 06 · SeasonsNo milkweed, no monarchsThe Ontario summer week by week: milkweed comes up, monarchs arrive, and the eggs follow.
Story 07 · Wind mapRiding the windA real cold front over Lake Erie in October 2026, the kind of wind change monarchs wait for before they cross.
Story 08 · TrackingFollowing one monarch at a timeRadio tags lighter than a tenth of a gram, and the monarchs from Long Point that carried them.Every number on this site has a source. The Data and credits page lists each dataset, its licence and how often we update it.
Every chart on this site started with someone who looked up and noticed.
Scientists, park staff and thousands of volunteers counted, tagged and photographed monarchs so these stories could be told.
Danaus plexippus late summer