Red Admiral Butterflies are on the Move

Red admiral resting on tufted vetch. Photo captured by Christoph Ng via iNaturalist.

A butterfly perched on top of a flower.
Red admiral resting on tufted vetch. Photo captured by Christoph Ng via iNaturalist.

You may have noticed more butterflies this spring, compared to recent years. If so, you’re not imagining it! 2024 is shaping up to be a successful year for red admiral butterflies.

The red admiral is a migratory butterfly species among the iconic monarch and closely related American lady species. The frigid winters in our area are too cold for these insects, even as a sheltered egg or pupa they can’t survive. Red admirals migrate to the southern United States during winter, just like us planning a tropical getaway. As spring arrives, some migrate back to Canada to take advantage of the abundant habitat and plant food sources.

Against all Odds

It’s commonly known that red admirals experience fluctuations in population trends, with good and bad years, but the reasons for this phenomenon are still unclear. A variety of factors influence how many butterflies survive in the southern U.S. and how many make their way up north. Fall and winter droughts or cold snaps that kill off predators and parasites could be a reason for their population growth, especially combined with an early spring that produces lots of host plants.

The last banner year for red admirals was 2012, when the butterfly made headlines for its sheer numbers. So far this year, people have spotted hundreds of red admirals in Ontario and reports along its migration path suggest that thousands more are on their way.

Be on the Look Out

A butterfly resting on blades of grass.
Red admiral butterfly, photo by Marc Johnson via iNaturalist.

At first glance, you may confuse red admirals with their more famous migrating cousin–the monarch butterfly. Monarchs are much larger than red admirals, with four wings that are orange and black from both sides.

A butterfly with orange and black wings resting on a plant.
A monarch butterfly resting on New England aster, photo captured by CVC employee Adrienne Ockenden.

When seen from above with their wings open, red admirals are mostly brownish black with an orange stripe and white spots. If you see them with their wings folded up, you’ll notice the grey-brown mottled patterns on their hind wings and a striking colour pattern of pinkish-red, blue and white on their forewings.

The Cycle of Life

Red admirals have at least two generations in southern Ontario. The adult butterflies that are now arriving here will mate, then use nettle plants as their egg’s nursery. It’s hard to imagine enjoying eating leaves covered with stinging hairs, but once red admiral caterpillars hatch and feed, they aren’t bothered. They go as far as nipping the hairs right from the base. After the caterpillars get their fill of nettle leaves, they encase themselves in a protective chrysalis that mimics a dead leaf, eventually emerging as an adult, ready to begin the cycle anew.

A caterpillar on a plant stem.
Red admiral caterpillar on a dame’s rocket stem. Photo by Andrew via iNaturalist.

Contribute to Citizen Science!

The red admiral may be a very common sight this spring and summer, but don’t let that distract you from appreciating its beauty. If you notice one sitting still, try to capture its photo and submit it to our ongoing Butterfly Blitz citizen science project. CVC is using the data from this project to inform our work to protect, restore and manage habitats throughout the Credit River Watershed.

By Laura Timms, Program Manager, Natural Heritage Management

Comments (14)

  1. Patricia (Draves) Wyszynski

    Dozens of Red Admirals on our Georgian Bluffs property (south of Big Bay, Grey Road 1)
    Feeding on dandelions and leaf litter.
    Did they overwinter in leaf litter or woodchips?
    The White Admiral does overwinter here.
    I have a few photos.
    May 02, 2024

    1. Credit Valley Conservation

      Red admirals don’t overwinter in Canada but spend the winter as adults or pupae in the southern U.S. Overwintering Red admirals in the southern U.S. would be found under bark cracks or flaps, or in leaf litter.

  2. Woke to find red admirals everywhere in our garden and converging to feed on our in full bloom plum tree! Spent entire day dodging them while I worked outdoors and watched them in awe! Must have been 50+ on my tree at any given time and just about everywhere else…when I walked a out I had to double check I wasn’t stepping on them! Brighton,Ontario near Presqu’ile.

  3. I took a photo of one on my deck Wednesday thinking it was a baby Monarch. This article was very helpful in that they are in fact Red Admiral Butterflies and why I have seen so many, so far, in different spots on my property. I live in Mono, just at the border of Orangeville, Ontario.

  4. Yesterday, a red admiral was enjoying the sun and cherry blossoms in our yard. It was almost invisible in the fence line leaf litter!
    (near Inglewood)

  5. I wish I could say that I have seen dozen of red admirals. We have however already seen 4 which outnumbers the other types of (bigger) butterflies we have seen so far (except sulphurs and silveryblues) . I think the campaign against the dreaded gypsy moth in 2020/21 did alot of harm to our populations. the gypsies were rampaging!

    Our meadow, planted with native plants, is dry sandy soil. We have an ever changing bloom starting with lupine and columbine. There are no moist areas right nearby for puddling. Although they could go into the forest which is lowland decidulous. larger excrement seems to be consumed by larger animals.

    We often see the admirals in the meadow on coneflower and showy goldenrod, yet no websites are noting anything other than the trees and honeysuckle as host and food (and poop).
    Can you comment on this?

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