Canadian Tiger Swallowtails Puddling
In April, during mud season, living on a dirt road can be a curse. But in May and June, when swallowtails emerge, it can be a blessing as you often witness a phenomenon called “puddling.” This phenomenon consists of clusters of butterflies (predominantly males) gathering to obtain salts and minerals that have leached from the soil into standing puddles and moist dirt.
Because butterflies do not have chewing mouthparts they must drink their meals. While nectar is their main source of nutrition, males often supplement their diet with minerals. The sodium uptake aids in reproductive success, with precious nutrients often transferred from the male to the female during mating. This extra nutrition helps ensure that the eggs survive.
Pictured are Canadian Tiger Swallowtails puddling. They are easily mistaken for Eastern Tiger Swallowtails as they look very much alike and their ranges overlap. To determine which you have seen, look at the underside of the butterfly’s forewing and see if the yellow band along the margin is solid and continuous (Canadian Tiger Swallowtail, Papilio canadensis), or if it is broken up into spots (Eastern Tiger Swallowtail, Papilio glaucus).
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.
Naturally Curious with Mary Holland 
What Other Naturally Curious People Are Saying