What role do native tree snails play in keeping the Hawaiian rain forests healthy? ​

Raised of $4,800 Goal
Ended on 7/07/16
Campaign Ended
  • $104
  • 3%
  • Finished
    on 7/07/16

About This Project

Although the diverse and colorful Hawaiian tree snails have been studied for many decades, the potential ecological role played by tree snails has only been the subject of speculation, and has never been scientifically addressed. We've recently confirmed that these arboreal snails graze on microbial biofilms that grow on host tree leaves, depositing feces, which wash down to the forest floor in frequent rain showers. Could this provide important natural fertilizer for the trees themselves?

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What is the context of this research?

The Pacific Islands can be considered an environmental microcosm of what is occurring on a global scale. Hawaii and other islands harbor sensitive native marine and land ecosystems that provide important air, water, and nutrient cycling services for human populations. In fact, people living in the tropics rely directly on native rain forests for abundant clean water, as intact forest ecosystems act as upland reservoirs, capturing and slowly releasing clean water. But natural ecosystems are being degraded globally at an alarming rate. In many cases, one of the drivers is release and establishment of nonnative plants and animals. In no place is this more evident than on islands, where accidental and intentional release of nonnative species wreak havoc on naïve, native organisms.

What is the significance of this project?

Considerable effort is currently being dedicated to protect and maintain the rare Hawaiian tree snails by government agencies as well as university researchers. But unfortunately, invasive predators are having a major impact on the survival of the tree snails: we have lost about 75% of the 100 species in recent decades. Nonnative predators include the wolf snail, rats and Jackson’s chameleons (see lab notes for photos). Therefore we seek to raise public and scientific awareness thru an understanding of the role of tree snails in Hawaiian forests, without which, justification of work to save them is challenging, in terms of public understanding as well as perception. We hope to generate data to allow us to say definitively what the snails provide to the tropical rain forest.

What are the goals of the project?

The goals of this study include obtaining both qualitative and quantitative information about potential differences in the nutrient environment between intact rain forests where the diverse native tree snail fauna is present, versus the increasingly common forest areas where the snails have been wiped out by nonnative predators. Our methods in this comparative study will include rinsing cages that contain only native plants, versus cages with known numbers and size classes of snails, present for known time intervals, collecting and analyzing organic chemical content of the waste, and comparing the results. Our goal is to show detailed analysis breakdown of organic nutrients nutrients in rain washed trees with snails and without snails present.


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We work with endangered captive Tree Snails in the Hawaiian Tree Snail Conservation Lab at the University of Hawaii, where we care for and maintain over 500 individual snails in a dozen species. Our work here entails regular cage changes where we replace leaves that have been in cages for several days, with fresh leaves that we collect in the mountains. We plan to collect accumulated fecal matter from cages, by washing out the waste from cages and leaves, which we will collect in sample bottles. The samples will then be chemically analyzed. The cost for laboratory analysis will be about $1,200, we supply cages, study organisms, facility, computers, and sample containers. Our results will indicate the organic compounds released from tree snail feces, as well quantify the amount produced per individual over time, in order to begin to understand the inputs that these populations have on Hawaii's rain forests. Without funding from Experiment.com this study could not be completed.

Endorsed by

This project is of crucial importance to the survival of Hawaii’s endemic tree snails and to our understanding of how Hawaiian forest ecology functions. Dr. Holland has decades of experience with the group and is the natural choice to lead this research.

Meet the Team

Brenden Holland
Brenden Holland
Associate Professor


Hawaii Pacific University
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Team Bio

During this investigation, we will work with Soil Biogeochemist Susan Crow, a member of the faculty in the Natural Resource and Environmental Management Department at the University of Hawaii, Manoa. We have an ethnically diverse and dedicated team of undergraduate and graduate students, interns and staff, who work passionately to understand and preserve natural biodiversity.

Brenden Holland

I think it was a Sylvia Earle said, "We have become frighteningly effective at altering nature."

I'm a broadly trained ecologist with interests in what we can do to maintain natural levels of terrestrial and marine biodiversity. The majority of scientific projects that I've been involved with in recent years have underpinnings in Conservation Biology, and have focused on quantifying and understanding ecological challenges, how to solve them, and ultimately how best to protect and preserve native species and their habitats.

I have an undergraduate degree in Biological Science from UC San Diego, and MS and PhD degrees in Oceanography from Texas A&M University. I grew up exploring the tide pools, kelp beds, creeks and redwood forests of the west coast, and somehow never lost my childhood curiosity about the natural world. I continue to this day to encourage my students to ask questions, and keep exploring. Along the way, I strive to instill in them the notion that, "By taking care of nature, we take care of ourselves".

Lab Notes

Nothing posted yet.

Additional Information

For those who are lucky enough to have seen Hawaii's unique tree snails in the wild while hiking thru the rain forests of the islands, it is clear that these rare native species are colorful, beautifully banded and captivating. As conservation biologists it is also clear that forests that retain their incredibly diverse native snail fauna are becoming more and more rare, and since these species are so sensitive to the presence of nonnative weeds, insects (ants), mammals (rats, pigs), reptiles (Jackson's chameleons), and even predatory snails (wolf snails), the very presence of tree snails serves as an important indication that these are high priority forests for preservation. But beyond their natural beauty and their role as sensitive indicators of forest health, we feel it is of the utmost urgency to show for the first time, what ecological role they may play in this fragile, threatened tropical ecosystem.

Our research group studies basic biology of native tree snails, as well as that of invasive taxa that threaten native forest species of the Hawaiian Islands, in order to ultimately devise control methods to protect these sensitive ecosystems and allow them to recover. Publications can be accessed thru public science portals such as ResearchGate and Academia.edu, links shown below.





Project Backers

  • 6Backers
  • 3%Funded
  • $104Total Donations
  • $17.33Average Donation
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