Improving capture rate for an invasive species in Mauritius: determining Asian musk shrew Suncus murinus bait preference.
The Asian musk shrew Suncus murinus is an invasive insectivore that first colonised Mauritius in the eighteenth century. It is a significant predator and poses a threat to terrestrial endemic reptiles in Mauritius. On the islet nature reserve Ile Aux Aigrettes, Mauritius, shrews predate juvenile Telfair's skink Leiolopisma telfairii, limiting the recruitment of this threatened species. It is therefore important to reduce numbers of Asian musk shrews, and live and fatal trapping are potential methods that can be used to control or eradicate invasive vertebrates. This study tested whether Asian musk shrews preferred the bait currently used for trapping shrews on Ile Aux Aigrettes compared to a novel bait, crushed cockroach. We also tested whether shrews preferred bait in the presence or absence of musk, a chemical attractant. Shrews were observed in a specially designed choice box where a behavioural tally recorded their activity. Their strongest preference was for compartments containing no bait, although they also displayed a significant preference for crushed cockroach in the presence of musk, and a lack of interest in the existing bait. These results suggest that the use of this novel bait plus musk could improve the success of trapping shrews on Ile aux Aigrettes and elsewhere.