Simultaneous monitoring of the same animals with PIT-tags and sensor nodes causes no system interference

Recent technological advances have multiplied the variety of biologgers used in wildlife research, particularly with small-bodied animals. Passive integrated transponders (PIT) have been used for decades to log visits of tagged animals at reader-equipped artificial feeders or roost boxes. More recently, novel miniaturized sensor nodes can collect data on social encounters among tagged individuals in any location. Combining these systems allows researchers to gather high-resolution tracking data on certain individuals from their long-term PIT-tagged animal populations. However, there can be a risk of interference among tracking systems. Here we tested whether placing an additional biologging sensor on top of a PIT-tag might attenuate the magnetic field reaching the PIT-tag and in turn hamper reading success of the radio-frequency identification (RFID) reader. We also evaluated data transmission by a digital sensor node in the presence of a magnetic field created by the RFID-antenna. The combination of this RFID-system and wireless biologging sensors works without error, suggesting that the simultaneous use of PIT-tags and other digital biologgers, e.g. miniaturized GPS-loggers, should also work together properly when communication channels do not overlap. The combination of long-term monitoring with PIT tags and short-term tracking with biologging sensor nodes creates exciting new opportunities to gather rich social data from individuals not present at RFID reader stations.