Hobbs Ridge To Mount Kaala, Waianae Summit (Part I)

[Part 1] [Part 2]

With the increase in foot traffic on the local trails due to social media, I constantly remind our crew to make sure our time in the mountains is well spent. Whether it being conservation work, mapping / surveying native species, invasive species removal or basic trail maintenance / clean up, I’ve always felt it is important to dual purpose our hikes, in addition to just enjoying the outdoors recreationally. A group of us (Nate, J, Katie, Ryan, Aaron, Jenelyn and I) recently did a moderate traverse along the Waianae Summit, from Hobb’s ridge to Mount Kaala. The purpose of this hike was to look for native land snail species for one of my colleagues at the University of Hawaii at Manoa, as well as to meet them at Mount Kaala for a basic lesson about land snails on Oahu.

Since the forecast called for muggy, Kona-wind weather, we started our journey at the end of Waianae Valley Rd, around 730am… in attempt to reach the Waianae summit before the heat of the sun was most intense.

After intersecting the summit from Hobb’s ridge (I’ll detail a little more about Hobb’s in my next write-up), we took a short break before continuing along the new fence line.

Hiking along the fenceline was slow… not only was it overgrown with thorny blackberry and itchy, molasses grass, the absence of winds made the summit-crossing less than pleasant.

At least some portions were more exposed,

…or shaded,

…as we approached the FAA tracking station on Kaala.

Besides shade, an abundance of native plants were welcomed. Kanawao, Kopiko, Ohia and Uki uki grass are some of the more common native plants we encountered on our journey, as shown in the photo above. In this area, we saw a few different species of native snails as well, which I talk more about later.

Up until this point we had not encountered any geographical obstacles, however some of the more technical sections were just after this large rock face.

Contouring around the right side of the feature, we had to traverse some narrow sections which had several sets of webbing pre-anchored. NOTE: Please exercise caution when using ropes / webbing left on trails. When ascending, it can be difficult to determine how secure the anchors are, in addition to verifying how much weight it can retain after being weathered for extended periods of time. I don’t usually mention this type of thing, but a reader recently complained that the site content didn’t adequately prepare him for a hike I had documented… Although I occasionally provide general tips or detail how we navigate obstacles, please read the website disclaimer and remember that the site content is not intended to be used as a guide to successfully complete trails.

Here, Nate ascends on of the more difficult obstacles, starting on the right and contouring left around the overhang and back right.

I and some of the others decided to hug the left side and traverse right to top out.

After completing this section, we were about 20-30 minutes from the southern end of the Kaala bog.

Several colored ribbons are present here, some from hikers and others from researchers who work in the bog. NOTE: It is important to recognize that not all ribbons indicate a trail, and sometimes mark plants, study sites, and paths to study sites of researchers. If absolutely necessary to flag a route, do not use the same color flags or combinations of colors present in that area. Moreover, do not tear down flags here as they could interfere with studies being performed here.

It took us about 15-20 minutes to cross the bog, before being greeted by my colleague and former classmate from grad school, Dr. Norine Yeung (her tongue extended in the photo above, lol).

Nori spent a good amount of time talking to us about land snails and current conservation work being done in the islands, before we start looking at some live specimens.

Normally, we are just used to seeing succineids, like the “snot in the hat” shown above; or helicarionids (Philonesia sp.) and achatinellids (Auriculella / Achatinella spp.), depending where we are in the Koolau and Waianae Mountains.

Here, she points out one of the more inconspicuous species to Nate and Tom, before placing it back on the Kanawao plant. Unfortunately, I wasn’t present for the entire explanation as I was looking for a specific plant that I saw a snail on earlier, that I wanted Nori to identify.

Further into the bog, Dr. Nori spots a less common helicarionid on another Kanawao.

This one is a Hiona sp., and though looks like Philonesia sp., it is much larger.

I won’t elaborate on any specific sizes, but it was probably twice as large (in shell diameter) than any Philonesia sp. that I’ve seen.

Nori also pointed out to us one of the more charismatic, but endangered Achatinella sp. at Kaala. They appeared to be “estivating,” or retracted into their shells to prevent moisture loss.

She mentioned that it is important not to disturb these and other native land snails during dry / drought conditions as they are already stressed.

Enlightened by our field lesson, we were also happy to have been educated on the highest point on Oahu.

We were also happy to have a ride down the Mt. Kaala Road, as I had let Dr. Nori borrow my Xterra for field work as part of the deal for a ride back down. haha.

Mahalo nui to Norine Yeung for sharing your manao and passion for native land snails.

Dr. Nori would also like to inform the general public and hiking community that collecting native snails is illegal. There are 1461 “described” land snail species, but more extensive surveying in remote areas could result verifying this number, as most have not been studied for over 70 years. Most of the current research on land snails focuses on the subfamily Achatinellinae (photos of one of it’s members shown above), which makes up for ~13% of Hawaiian land snail fauna. Virtually all of the described species are endemic, except for a handful so therefore 99.9% of them are found here and no where else in the world. Some of the biggest threats to native land snails are habitat destruction, impacts of invasive species (e.g., predation, competition for resources, disease, etc.) and climate change (this topic deserves a more detailed explanation, but I’ll save it for a more another write up). For hikers in particular, trampling may be a big threat to land snails, as several inconspicuous species live in the leave litter and moss found on the ground along hiking trails in upper elevations. Please do not intentionally disturb any native land snails, especially during dry weather. If in the case that you find a native snail on your clothing or gear, please place in back on a native plant (e.g. ohia) near you, off of the main trail.

More questions about the hike or snail survey?? Just ask!!!

Dr. Nori and her land snail colleagues can be reached here:
facebook.com/Hawaiian.Land.Snails

As with any hike or outdoor adventure here in the islands, please know when you are in over your head and know when to turn back. Please properly prepare yourself and hike with others who are capable and who you can trust. Please stay safe out the trails out there and have fun!

Aloha and mahalo nui for visiting… Come back again soon!