Fern Glen Essays
If you can't get blood from a stone, try nectar.
by Barry Haydasz

What do butterflies eat? What is this - a trick question? Everybody knows butterflies drink nectar from flowers, right? Well, yes, by far most do. But many supplement their diet from other sources. Indeed, some use other sources almost exclusively, rarely, if ever, visiting a flower at all.

It was, as usual, a chance encounter that got me pondering the subject. As I strolled up the sidewalk of the Gifford House one day, movement caught my eye. It was a northern pearly-eye taking brunch on guano from the little bat colony under the eaves. (Click on the image for a larger view.) I recalled reading that dung and urine are popular sources of salts, nitrogen, and amino acids.

I began musing about the various, sometimes surprising things I have found butterflies feeding on. Rotting fruit is attractive to many butterflies and moths for the sugars. Lepidopterans, by the way, are not immune to the effects of fermentation products... A red admiral is dining from a simple feeder consisting of a plastic tray hanging from a tree. Don't neglect a few drain holes so that rainwater doesn't accumulate and pose a drowning risk. I call it the "birderfly" feeder, for as well as attracting insects, it attracts insectivores...

Of those that do visit flowers, some are very specific in their choice; others are rather general. The structure of the proboscis - the coiled tongue - can be a factor. A long tongue is able to probe deep tubular flowers such as lilies; a short one would be better suited for, say, composites such as daisies. Then again, I have observed a diminutive skipper at the base of a large flower - on the outside - where it inserted its modest proboscis between the petals to reach the nectar within, so "skipping" the whole purpose of the flower: pollination.

Tree sap is one of the first sugar rich substances available in the Spring. Anglewings and tortoiseshells overwintering as adults can be seen sunning and sipping on tree trunks on those sunny 45F February days. Here, an eastern comma, a pair of common wood-nymphs and a host of other critters share the sap of a recently pruned honeysuckle bush.
	The salt in sweat brings about many close encounters. Here, an eastern comma feeds literally by the sweat of my brow.
Carrion was a surprise to me when I spotted a diminutive spring azure working over a deer carcass. No one fell for my description of how, in fall, they flock together and drive a deer over a cliff so that in spring they will have something to eat before the flowers blossom.
	I was having my morning coffee when a common wood-nymph landed on the sliding glass door. What interest could hot, dry, sun baked glass possibly hold for a butterfly? I dropped onto my elbows and eased up slowly across the carpet until we were proboscis to proboscis, separated only by a layer of glass.
Oh, this is where the cat bangs his head and rubs. Cat spit and ear wax? Yuk! But it's been baked and caked on there; how could... It was then that I noticed little ripples of distortion around the point of contact. Ripples of wetness... that appeared and disappeared wherever the proboscis probed. Not only could it suck in, but it could exude fluids as well! It could lick!!
	Most of us have observed butterflies, such as these pearl crescents, flocked along roadside puddles. Often, these are males taking up dissolved mineral salts necessary for producing their reproductive offerings. Damp soil or gravel, even a dusty dirt road is alluring to many.
This Baltimore checkerspot is apparently eating a stone. Look closely - the stone is wet under its tongue. We know how that happens now... So, if you can't get blood from a stone, try nectar.

Questions, comments, or other feedback to Judy Sullivan.