Puddle Clubbing with Swallowtails!


An exciting tangent to my annual camping and fishing trip in the mountains of northern Pennsylvania is the opportunity to witness butterfly “mud-puddling”.


Prime habitat for a puddle club of swallowtails: a gravel parking area along a mountain road in a heavily forested area, with plenty of mud puddles and sun.

Many species of butterflies puddle, but aggregations of eastern tiger swallowtails in the endless deciduous forests of this region are spectacular. They’re unlike anything I’ve ever seen in the Northeast.


A “puddle club” of eastern tiger swallowtails


Most puddling butterflies are fresh males and the event lasts but a few days in late May and early June.


Do butterflies puddle due to a scarcity of nutrients, as an alternative foraging strategy arising from competition, or a combination of factors? There is still much to learn about puddling, but the most convincing hypothesis supports resource scarcity.


Sodium ions and amino acids ingested by puddling male butterflies are transferred to females during copulation, enhancing egg production and survival.


Puddling behavior is well known in gardening circles and there are many published strategies for creating butterfly puddle-clubbing habitat in formal landscapes. Once you’ve been immersed in a wild, surreal scene like this, it makes sense. Totally!


Photos by NB Hunter (late May and early June, 2017). © All Rights Reserved.