Overcoming hermit-crab interference during rodent-baiting operations: a case study from Henderson Island, South Pacific

A successful rat eradication strategy for Henderson Island, South Pacific, is feasible despite high hermit-crab interference. Researchers determined that even with crab densities reaching 1370 crabs per hectare—where they consume up to 3.8 grams of bait daily—rats can still be effectively targeted using rhodamine-dyed cereal pellets. By adjusting bait application rates, the study achieved 100% bait consumption by rats across four plots, demonstrating that careful planning can mitigate crab interference. This insight provides a model for other eradication efforts facing similar challenges, though it also underscores the need to assess potential impacts on non-target species like hermit crabs. The findings were derived from distance sampling of crabs and mark-recapture studies of rats, combined with hand-applied bait trials.

Cuthbert, R. J., Brooke, M. d. L., & Torr, N. (2012). Overcoming hermit-crab interference during rodent-baiting operations: a case study from Henderson Island, South Pacific. Wildlife Research, 39(1), 70–77. https://doi.org/10.1071/wr11033