We miss the redwoods so we went to the Butano State Park which is one hour drive away from our home in Santa Cruz mountains. The redwoords in the Butano park are nothing like what we saw up north – the place was logged a few times, redwoods there are mostly under 100 years old. But the banana slugs in the State Park were a delight!
A banana slug first identified by my Zozo
The Pacific banana slug is native to the forest floors along North America’s Pacific coastal coniferous rainforest belt (including redwood forests) which stretches from Southeastern Alaska to Santa Cruz, California. I heard of the slug ever since I moved to California but hadn’t seen it in person. When my little Zozo was screaming “Banana Slug” on our hiking trail, her parents didn’t know what she was talking about… Zozo paid attention to the state park brochure! She identified the very first banana slug for the family!
Banana Slug is everywhere
According to Wikipedia, the banana slug is the second-largest species of terrestrial slug in the world, growing up to 25 centimeters (9.8 in) long, and weights of 115 grams (4.1 ounces). (The largest slug species is Limax cinereoniger of Europe, which can reach 30 centimeters (12 in) in length.)
A banana slug eats whatever on a forest floor – they keep the forest clean
Banana slugs have a single lung which opens externally via pneumostome. That explains the hole we saw on these slugs. The pneumostome lung cavity is heavily vascularized to allow gas exchange.
The slug’s slime contains pheromones to attract other slugs for mating. Banana Slugs are hermaphrodites, and reproduce by exchanging sperm with their mate. I was so lucky to capture a pair in action. 
Slugs mate and lay eggs throughout the year. The adults provide no further care for their eggs beyond finding a suitable hiding spot, and the eggs are abandoned as soon as the clutch is laid.
Two banana slugs mating – See the hole that’s the lung?
Banana slugs have been used as food by Yurok Indians of the North Coast and by German immigrants in the 19th and early 20th centuries. A yearly festival and contest is held at Russian River (California) including slug races and a contest for recipes. I would rather eat chicken feet dim sum.:-)
Leilei found another banana slug
A little banana slug making it on its own