Butterflies sometimes prefer mud puddles to flowers as a way to get needed nutrients

Butterflies and flowers appear inseparable — and for good reason.

Many plants produce flowers rich in nectar, the sugary fluid upon which butterflies feed. And butterflies, while foraging, transfer pollen from one blossom to another, playing a vital role in pollination.

Butterfly mouth parts are fused into a long straw-like structure well adapted to their liquid diet. This “proboscis” coils up neatly when not in use.

But butterflies don’t always drink nectar.

Many also congregate to sip liquids from wet soil, sand, mud puddles, or other substrates — even dung or carrion. Some species seem attracted to perspiration on human skin.

This seemingly odd behavior, called “mud-puddling,” provides salts and amino acids that are otherwise lacking in a nectar-rich diet.

Mud-puddling in butterflies has become the focus of many scientific studies, as its adaptive functions are not fully understood.

Studies have shown, though, that it’s particularly common among males, which incorporate these extra nutrients, especially sodium, into the spermatophores (sperm packets) transferred to females during mating.

Females benefit from the extra salt supply via enhanced egg production. Their mates, in turn, profit by higher reproductive success.

In some species, though, the extra sodium males get from mud-puddling may be more related to supporting the high neuromuscular requirements of flight.

Mud-puddling occurs in many species — Cabbage Whites, Black Swallowtails, Tiger Swallowtails, Pearl Crescents, Cloudless Sulphurs, Red Admirals, and many other common butterflies in the Lowcountry. Some moths also perform this behavior, as do a few other insects, such as leafhoppers and bees.

Even at the beach, you can find mud-puddling butterflies. Gulf Fritillaries, for example, often gather to drink from wet patches of sand.

To attract more butterflies to your yard, try setting aside a small patch of soil in a sunny area and keeping it moist. You could also add a bit of manure or compost.

This story was originally published July 14, 2022 at 8:50 AM.