The Things You’ll See: New Butterfly Behavior Seen on Big Year Trip

Participants in last weekend’s GGNP Endangered Species Big Year Mission Blue Butterfly hike got a rare and scientifically important treat: they not only saw a Mission Blue, but also watched it engage in a behavior not previously proven to occur in the subspecies.

Mission Blue Butterfly Mud-puddling in the GGNP

The rare butterfly was seen “mud-puddling” from the SCA trail in Marin County. Mud-puddling occurs when butterflies congregate on moist soils or other substrates to obtain nutrients, such as amino acids and salts. These nutrients are believed to help the butterflies reproduce: males that mud-puddle tend to increase their reproductive success, if only because they sometimes transfer the nutrients to the female while mating as a nuptial gift! We’re glad to see one of the rarest butterflies in the GGNP finding new ways to gain a reproductive edge.

Although other members of the genus were known to mud-puddle, it was unclear if Mission Blue Butterflies engaged in this behavior: butterfly experts had debated this point. The new observation with photographs provides evidence of mud-puddling in this subspecies.

To find out how you can see and help save the Mission Blue and the 35 other endangered species at the Golden Gate National Parks, click here to sign-up for your GGNP Endangered Species Big Year!

Remember, participants must follow the Big Year’s ethical principles. This butterfly was seen from the SCA trail, not off of it, so participants on last weekend’s trip can count the sighting as they compete for the GGNP Endangered Species Big Year’s grand prize!