Butterflies love to party

I was walking along a creek in North Georgia's Union County the other day when I passed by an old campfire site ringed with soot-covered rocks still moist from a recent shower.

Suddenly, a cloud of blue insects erupted from the fire-scarred rocks:

I had crashed a “drinking party” of butterflies known as summer azures -- beautiful light-blue creatures that are some of Georgia's smallest butterflies.

If you walk regularly in the outdoors, you've probably come upon similar scenes -- several brilliantly colored butterflies gathered on mud, wet rocks, moist sand or even on fresh dung, obviously attracted there by something desirable.

Many folks call these aggregations drinking parties or “puddle parties.” The parties may range in size from a few butterflies to a hundred or more. The summer azure party I interrupted had attracted some 30 individuals.

In addition to summer azures, drinking party attendees also often include a variety of other butterfly species -- swallowtails, cloudless sulfurs, sleepy oranges, red spotted purples, eastern tailed-blues, harvesters and American snouts. Interestingly, nearly all the partygoers are males.

What lures them? By sipping moisture at the party sites, the butterflies not only get water but they also absorb dissolved salts and minerals that are important for reproduction.

Butterflies, of course, get most of their nutrition from flower nectar. But although nectar is rich in sugar and energy, it lacks these nutrients. Instead, males must get them at puddle parties.

When butterflies mate, these nutrients are transferred to the female through the male's sperm. The extra salts and minerals improve the viability of the female's eggs, boosting a butterfly pair's chances of passing on their genes to another generation.

Since the females receive nutrients from their male partners during mating, their nutrient uptake needs aren't nearly as great, perhaps explaining why there are far fewer females at puddle parties.

IN THE SKY: From David Dundee, Tellus Science Museum astronomer: The moon will be new on Monday. Mercury is low in the east just before sunrise and will appear near the moon Sunday. Venus is higher in the east, rising about two hours before sunrise. Mars rises out of the east about midnight. Jupiter and Saturn rise in the east around sunset.

COURTESY OF CHARLES SEABROOK Summer azure butterflies hold a “drinking party,” where they sip moisture with dissolved salts and minerals from the surface of a rock in North Georgia’s Union County. The nutrients are vital for butterfly reproduction.