Telemetry tails: a practical method for attaching animal-borne devices to small vertebrates in the field

Abstract

Context Continued miniaturisation of tracking technology increases its utility in animal applications. However, species morphology often dictates the type of animal-borne device (ABD) that can be used, and how it is attached. The morphology of species within Peramelemorphia preclude them from the standard collar attachment of ABDs for terrestrial mammals. Aims This paper describes a method for the tail-mount attachment of ABDs, and deployment results for Peramelemorphia across arid, semi-arid and temperate Australia to (a) test the performance of attachments and ABDs in the field and (b) discuss the animal welfare considerations for this attachment method. Methods Tail-mount attachment of ABDs were field-tested on a total of 80 greater bilbies (Macrotis lagotis), and 14 long-nosed bandicoots (Perameles nasuta). Key results Time to natural detachment (TTND) was between 2 and 52 days, with 65.74% (142 of 216) remaining on until manual removal. For ABDs that were manually removed, attachments were retained for up to 94 days. The method used for tail-mount attachment of ABDs to long-nosed bandicoots resulted in significantly shorter TTND compared with the method used for bilbies, and environmental factors (high temperatures and rainfall) had a negative effect on TTND. Tail-mount attached global positioning system (GPS) sensors collected large quantities of accurate data, with a maximum fix success rate of 83.38%. Damage to GPS (antenna breakage and water ingress) during deployment, however, impacted performance. In environments with frequent rainfall and waterlogged soils, the tape on a small proportion (6.25%) of (n = 192) attachments to bilbies caused tail injury. All injuries were resolvable, with most requiring minimal to no veterinary intervention. Key conclusions Attachment longevity can be affected by how the ABD is mounted to the tail, the species and the deployment environment. The environment can also affect which adhesive tapes are suitable for ABD attachment. However, this method is highly modifiable, practical for field application and can have long retention times relative to other temporary methods. Implications This ABD tail-mount attachment method adds another tool to the telemetry tool-kit, with all the benefits of a low-tech, low-cost, passive drop-off type attachment. This method has demonstrated practicality for Peramelemorphia, with potential application to other suitable small vertebrates.