Using microchip-reading antennas to passively monitor a mammal reintroduction in south-west Queensland

Abstract

Microchip-reading devices provide an inexpensive and efficient means of passively detecting and monitoring wildlife reintroductions, particularly where intensive methods such as trapping and radio-tracking may be difficult or pose risk to animal welfare. We trialled the use of microchip-reading antennas for post-release monitoring of the survival of bilbies (Macrotis lagotis) for a reintroduction in south-west Queensland. The antennas detected 76% of the released captive-born bilbies (all microchipped) and 30% of the microchipped wild-born bilbies during the study period. Overall, the microchip-reading antennas greatly improved the rate of detection for bilbies in the enclosure compared to cage trapping alone. Of the 42 bilbies that were microchipped and had the potential to be recaptured in traps or detected on microchip readers, 33 were recorded from the combined approaches, with 20 bilbies recaptured in traps and 29 bilbies detected on the microchip readers. Antenna location/placement should be carefully considered in the context of the target species’ home range size as it may affect the probability of animals encountering the antenna. Here we demonstrate the ability to use these microchip-reading antennas to passively monitor post-release survival in a remote location, just one of many potential applications for these devices in wildlife management and conservation.