Anin situvertebrate bioassay helps identify potential matrices for a predator‐based synthetic management tool

Abstract

AbstractTo assist management and conservation needs, researchers have called for active kairomones to be elucidated and synthesized directly from animal exudates. However, the existing literature does not provide guidance on how to initiate this complex process. To our knowledge, composite synthetic predator scents that incorporate multiple compounds to accurately mimic the natural signal have not been produced. One approach to improve the accuracy of synthetics is to identify and recombine all major infochemicals within a benign solvent. Therefore, we tested 2 natural, pre‐existing matrices for their potential as vehicles for delivery of a predator scent, dingo (Canis lupus dingo) urine, which causes a startle reaction among western gray kangaroos (Macropus fuliginosus), and avoidance by European foxes (Vulpes vulpes). We compared 2 putative backbone matrices—aged (3‐yr old) dingo urine from a previously active lot, and 10% methanol—to a distilled water control. We used a novel fence‐crossing assay to observe kangaroo interactions with both solvents and a negative control. Our assay allowed us to control for high feeding motivation by testing compounds away from the food source. We determined that neither free‐ranging kangaroos nor European red foxes were adversely affected by either treatment matrix. Foxes were, however, attracted to the aged dingo urine, and were often observed scent‐rolling in the inactive substance. Our results suggest that dilute methanol could be a possible matrix for predator‐scent applications for kangaroos, while aged scents may act as an attractant for nontarget species, particularly canids. © 2012 The Wildlife Society.