Natural Connections

Butterflies are weird

A female monarch butterfly probes a bergamot flower for nectar using her proboscis. Photos by Emily Stone.

On one of those steamy, hot, and humid mornings last month I found myself staring out of my air conditioned office at the museum’s vibrantly blooming pollinator gardens. Movement caught my eye, and I wandered outside with my camera and tripod to catch some of the action. By the end of the day, I had realized that butterflies NATURAL are not only lovely, but CONNECTIONS really, really weird. As I’d hoped, a lovely orange EMILY STONE butterfly was sipping eagerly from the pale purple bergamot flowers. Zooming in, I could watch as she probed the cluster of tubular flowers with her delicate proboscis. Except, calling it sipping isn’t quite accurate.

A butterfly’s proboscis is more like a paper towel than a drinking straw. Like a paper towel absorbs water when even a corner touches the puddle of spilled milk, tiny grooves on the inside of the proboscis pull liquids upward using capillary action. The inner structure of the proboscis also breaks the column of liquid into tiny droplets that pose less resistance.

Trying to suck the liquid up would require more force than the butterfly can exert, especially since butterflies don’t just drink thin nectar, they also consume water from puddles, juice from rotten fruits, animal tears, tree sap, and several other unexpected substances of widely varying thickness.

As you might expect, different butterfly species have fine-tuned their proboscises to match their preferred food – even dried food.

Earlier this June, on a trip to Moquah Barrens, I snapped some photos of a dense mass of silvery checkerspot butterflies crowding around a lump in the sandy wheel track.

What were they eating?

A closer look revealed that the lump was a hairy, old wolf scat. Your first reaction to this might be a revolted “why?” Your next question might be “how?”

Let’s tackle the “how” first.

It’s actually pretty simple. Butterflies can send watery saliva down through their proboscis and onto the dry surface, where it picks up the substances they desire, and then travels back up the tube’s tiny grooves.

Remember when we used to make Kool-Aid by adding water to powder?

The “why” is a little weirder.

Butterflies are drawn to the scat (poop) of carnivores, but also to mud puddles, rotting plants and dead animals. Those gross things are a source of the nitrogen and sodium that are lacking in the butterflies’ usual diet of flower nectar.

In most species, only males will “puddle.” He then passes these valuable nutrients on to a female when they mate so that she can use them to produce healthy eggs. It’s called a “nuptial gift.”

I mean, who wouldn’t want a little packet of the essence wolf scat or mud puddle on their wedding day? These silvery checkerspot butterflies are able to extract nutrients from wolf scat by sending saliva down their proboscis get it wet, and then drinking the resulting saltand nitrogen-rich soup. Seriously, those are two of my favorite she extends her ovipositor, and uses things! the two photoreceptors to tell her that

Speaking of butterfly mating it isn’t obstructed by a bit of schmutz, practices (I did mention that the day which would block light, and also eggs. was hot and steamy?), the museum Finally, as she pushes her ovipositor staff got a good laugh last week when against the leaf, pressure sensors tell one of our volunteers walked across her that a leaf is really there, and she town just so she could impress us with deposits an egg. the fact that “butterflies have eyes on The full story of the discovery of the their genitals!” That sent me down a photoreceptors is pretty fascinating, Google black hole! and I recommend reading the full

Well, technically they are simply article, “Hindsight of Butterflies: The photoreceptors that can detect ultraPapilio butterfly has light sensitivity violet light, not eyes that can see in the genitalia, which appears to be movement and shapes, but it’s still an crucial for reproductive behavior,” by impressive discovery (by accident) into Kentaro Arikawa of Japan. the sensory world of butterflies. That monarch who was (not sipping)

This research was done on the on the bergamot flower fluttered away. Japanese yellow swallowtail butterfly in I’ve always admired butterflies for their 2001, but extraocular photoreceptors – beauty and pollination services – but light-sensitive structures that are found in hindsight – the weirdly elegant outside of an eye – occur in many solutions they’ve found to life’s various animals. problems are even more amazing.

What’s the use of literally having If you’d like to see video of the “hindsight”? butterfly feeding on the beramot, go to

It’s different for males and females. https://youtu.be/ABCMfqV2ExI. They both have two small patches of photoreceptors covered by transparent Emily Stone is the Naturalist/Education cuticle. In male butterflies, the patches Director at the Cable Natural History are located so that when he has sucMuseum. Her award-winning second book, cessfully connected with the female Natural Connections: Dreaming of during mating, the photoreceptors an Elfin Skimmer, is now available to go dark. Once he knows his aim is purchase at cablemuseum.org/books. Or true, he can deposit both sperm and a order it from our friends at redberybooks. nutritious nuptial gift that also acts as com to receive free shipping! For more a plug. than 50 years, the Cable Natural History

In females, the photoreceptors aid in Museum has served to connect you to egg laying. The whole process takes at the Northwoods. The museum is now least three types of sensory organs! open with the brand-new Mysteries

First, a female butterfly will use of the Night exhibit. Connect with us chemical receptors on her front legs on Facebook, Instagram, YouTube, and to taste a plant and make sure it’s the cablemuseum.org to see what we are up to. right species for her caterpillars. Then