Laboratory rats as conspecific biocontrol agents for invasive Norway rats R. norvegicus

We tested whether conspecific attraction can be more efficient than food bait for the detection and capture of an invasive, social species, the Norway rat Rattus norvegicus. We compared trapping rates between male and female laboratory rats and food baited controls at four mainland sites with low rat population densities, three recreational sites (Zoos) with an abundance of food in the environment, and in manipulated island rat incursions. Live lures were more efficient than food baits at both the mainland and recreational sites. There were no differences between the attractiveness of lure animals based on gender either of the lure or of the captured animals. In the manipulated rat incursions, where radio collared male rats were released on a rat free island, two animals were caught with female lures, and the third lost its collar and evaded detection. In the current study we advocate that animal behavior can help inform and guide innovative tools for the control and management of invasive species. We show that laboratory rats might be efficient as lures for their wild counterparts. Furthermore, our results emphasize the need for a flexible and varied rat control toolbox. We suggest that the use of laboratory rats should be considered in future control management plans for invasive Norway rats.