Observation of the Week August 19 to 25, 2023

Our 16th OOTW comes from Dave (@dmreid) with this observation of a Red-spotted Purple! This particular specimen was found during our Butterfly ID walk at Riverwood on August 19. After admiring and photographing its beautiful orange and blue patterns, the butterfly was quickly released.

Often found in woodland areas, particularly near waterways, the Red-spotted Purple was initially thought to be its own species entirely. However, it has since been recognized as a more southern subspecies of the White Admiral butterfly.

This is an incredible example of butterfly evolution, as these subspecies look quite different. The White admiral has prominent white bands along its wings, and the Red-spotted Purple lacks those bands. The Red-spotted Purple has a drastically different pattern because of an evolutionary adaptation that allows it to mimic the far less palatable Pipevine Swallowtail butterfly. Predators have learned that the Pipevine Swallowtail is distasteful at best, and poisonous at worst. The Red-spotted Purple benefits by mimicking the look of this swallowtail, giving it a scary reputation that it hasn’t really earned.

That being said, we’re lucky enough to live in an area where both subspecies exist together, so while looking for butterflies in the Credit River watershed, you’ll definitely have the potential to find both Red-spotted Purples, AND White Admirals.

And to make matters slightly more confusing, these species are known to hybridize in this range! Their (very beautiful) offspring could definitely end up in your net, as one recently did for Christine (@birds-blooms-butterflies) in the picture below, showing the hybridized White Admiral x Red-spotted Purple (or Limenitis arthemis arthemis x astyanax).

All this to say that the Red-spotted Purple has evolved over time to fake it in order to make it. And make it they have, as a beautiful addition to the 2023 Butterfly Blitz!

Contest Alert!
Don’t miss the Butterfly Blitz Bingo Challenge!
If you’ve ever played Bingo, you already know what to do. Use your iNaturalist observations to complete one of the rows on the Bingo card below. You may already have all the observations you need for a row, or maybe you just need one more … check it out! This red-spotted purple observation would go well on squares O2 or O3 of the August BINGO sheet, what do you think?

The challenge will run from July 1 to September 13! Here is how to participate:

1. Enroll in the 2023 Butterfly Blitz.
2. Join the 2023 Butterfly Blitz project on iNaturalist.
3. Complete a Butterfly Blitz Bingo row, column, or diagonal line and fill out this form (https://www.cvc.ca/ButterflyBingoForm) to be entered into a draw to win an Individual Credit Valley Annual Parks Pass. Complete Contest Rules.

Happy butterflying,
Derek and the Butterfly Blitz team
This week’s OOTW was written by Derek Stone, Program Director at The Riverwood Conservancy.

Posted on August 29, 2023 03:48 PM by kristenvalencia