Green Island's Land Crabs Facing Fewer Roadblock Disasters, Thanks to Taiwan Biodiversity Research Institute's Ingenious Solutions
Redesigned crossings lead to decrease in crab fatalities on roadways
Staff writer, Esme Yeh breaks down the Taiwan Biodiversity Research Institute's latest success: reducing road deaths of land crabs on Green Island by a staggering 50%! Those gigantic sea dwellers breed during summer, making them popular among tourists visiting the picturesque Taitung County locale. However, the masses of female land crabs moving towards the sea to release larvae find themselves ending up as hood ornaments during the peak tourist season due to vehicular collisions.
The Taitung County Government, in tandem with local authorities, along with the Taiwan Biodiversity Research Institute, have overhauled the island's roadways by installing some 19 innovative crossings for those critters - including underground tunnels, drainage channels, and bridges!
What's interesting, you ask? Well, the study was financed by the Tourism Administration's East Coast National Scenic Area Headquarters and involved experimenting with polyvinyl chloride (PVC) pipes as guides for the land crabs, particularly the red apple crab and terrestrial hermit crab.
By dividing two culverts en route a coastal road near Shilang into control and experimental groups, the institute aimed to slash the number of deceased land crabs. And let's just say they took control of that situation!
The experimental culvert became home to nifty PVC pipes with a 10cm diameter, linking the seaside exit to the coast, in addition to longitudinally halved sections of the same diameter PVC pipes lining the retaining wall to direct crabs to the hillside culvert entrance!
Over 29 and 25 surveys conducted between May and August in 2022 and 2023, respectively, observed the movements of 1,833 land crabs. And the research outcomes indicate that the guiding facilities significantly increased the usage of crossing culverts for both species!
The experimental group boasted more than half the roadkill rate reduction compared to the control group. Switching lanes never looked so good!
With future designs promising a boost in pipe diameter for better ventilation, improved connections between pipes and culverts, and the clearing of obstacles, those pesky, yet crucial land crabs will be moving in style. And due to the success of their underpasses, they're planning to more facilities for seaside exits, making sure the crabs make it back home without another detour!
Look out for the Taiwan Biodiversity Research Institute's study in the journal Global Ecology and Conservation next month! In the meantime, they'll continue working alongside local authorities to safeguard Green Island's endangered species while minimizing the impacts on tourism.
The Taiwan Biodiversity Research Institute's study, funded by the Tourism Administration, focuses on the health-and-wellness of land crabs and the environmental-science aspect of creating underpasses for their seaside exits. The reduction in roadkill rates by 50% is attributed to the installation of innovative crossings like underground tunnels, bridges, and drainage channels, as well as the experimental use of polyvinyl chloride (PVC) pipes as guides for crab movement.
