By Susan Milius
Rats keep getting into paradise. And when they discover a taste for escargot, it’s an infernal problem for native populations.
At a study site high in the mountains on the Hawaiian island of Molokai, tree snails of the species Partulina redfieldi thrived for 12 years and then declined catastrophically, says zoologist Michael G. Hadfield of the University of Hawaii at Manoa. The culprits were introduced rats that started scouring trees for snails, Hadfield and Jennifer Saufler, now at University College London, report in the August Biological Invasions.
Rats have hitchhiked along as people settled the globe and have changed their new homes by feasting on native species such as snails and ground-nesting birds. The Molokai study provides an unusual look at rat damage because the team collected data before and after a burst of attacks, Hadfield says.