Zebra Longwings

I took this picture of a Zebra Longwing butterfly at Paynes Prairie Preserve State Park the other day.

Zebra Longwing on Bidens alba

Zebra Longwings (or Heliconians) are the Florida State Butterfly. I grew up in Utah and had never seen one until I moved to Florida. They're beautiful and photogenic butterflies, with their black and white zebra stripes, red spots and blue compound eyes. And they do indeed have long wings. They're gentle, slow fliers that waft through the landscape. They are (usually) fairly common and stick around late into the fall. But last year they were completely absent, all year. We had an extremely harsh winter in 2010-11, with record cold temperatures. We had 27 days of below freezing temperatures, which may sound like no big deal for someone in the northern climes, but down here in the subtropics, the weather killed our landscape plants. In South Florida the iguanas were dropping out of the trees (which was probably a good thing--more on that another time!). The Zebras are not cold hardy, so their populations froze back to South Florida, where the winters weren't quite so cold. I never knew how much I had come to love them until they didn't appear. No one was sure how long it would take for the Zebras get back north. One person I talked to said it could be years. This past winter was cold again, but not as bad as the year before. Early in the spring, my husband and I took a trip to Miami. We saw Zebra Longwings all over the place and it was so nice to see them again. It made me sad to think that we wouldn't be seeing them in Gainesville for a long time. So you can imagine my reaction when I saw a couple at our botanical garden in early summer. The Zebra Longwings returned! Over the summer I saw more and more, and now I feel like the population is about back to normal. In fact, I just saw one drift past our dining room window. What a relief!

Zebra Longwings are cool butterflies. As I mentioned, they are primarily a tropical or subtropical species, so are not cold hardy. But they are fairly long lived, as far as butterflies go. They can live for several months, as opposed to weeks, because they eat pollen along with the nectar from flowers--a very unusual butterfly behavior. Their host plant is Passion Flower (Passiflora sp.). The Gulf Fritillary also uses Passion Flower as a host plant, but (this is so cool!) Zebras lay their eggs in the shade, and Fritillaries lay theirs in the sun. We had a big passion flower vine in the yard of our previous house and I watched this in action. The two types of butterflies would segregate their populations between the shady and sunny places in the yard. The females lay their geometric looking eggs on the tips of the new leaves, and soon the tiny white and black caterpillars emerge.

Zebra Longwing Caterpillar

When they finally pupate, the chrysalis looks just like the dried leaf of a passion vine. They blend in perfectly. The chrysalis is beautiful, with numerous irridescent patches that look like jewels or stained glass windows.

Zebra Longwing Chrysalis

Zebra Longwings engage in something called "pupal mating". As a human, I find this rather repulsive. But in biological and evolutionary terms, it makes great sense, because it provides a better chance that the first male's genes will be passed on. Males will crowd around a chrysalis where the new female butterfly is almost ready to emerge. They fight to be the first to mate with her, thus ensuring that their semen is first to fertilize her eggs. Sometimes the males will mate with her before she's emerged from the chrysalis. The first time I saw this, I had no idea what was happening. I thought the emerging butterfly was in distress and the nice butterfly friends were helping it out. Then I read up on Longwings and discovered what was really happening!

Attentive Male and Chrysalis

One other interesting behavior is roosting. Groups of Longwings will gather together at night to keep warm. They don't do it on the scale of Monarchs overwintering in Mexico, but they can sometimes form fairly large bunches. We had a Lepidoptera graduate student watching roosting Zebra Longwings in our yard to understand what chemical cues they use to return to the same spot.

Blurry picture of Roosting Zebra Longwings

So you can see that I'm a fan of the Zebra Longwing. I'm glad they have returned and will look forward to watching them well into the fall.