BATS: Adaptive Ultra Low Power Sensor Network for Animal Tracking

Stockmaier

Carter

2020

Preprint

11Sickness behaviours, like lethargy, can slow the spread of pathogens across a social network. 12We conducted a field experiment to investigate how sickness behaviour reduces individual 13 connectedness in a high-resolution dynamic social network. We captured adult female vampire 14 bats (Desmodus rotundus) from a wild roost. To create 'sick' bats, we injected a random half of 15 the bats (n=16) with the immune-challenging substance, lipopolysaccharide, and injected 16 control bats with saline (n=15). Over the next three days, we used proximity sensors to 17 continuously track their associations under natural conditions. The 'sick' bats showed a clear 18 decrease in social connectedness (degree, strength, and eigenvector centrality). Bats in the 19 control group encountered fewer 'sick' bats and also spent less time near them. These effects 20 varied by time of day and declined over 48 hours. High-resolution proximity data allow 21 researchers to define network connections based on how a pathogen spreads (e.g. the 22 minimum contact time or distance for transmission). We therefore show how the estimate of the 23 sickness effect changes as network ties are defined using varying distances and durations of 24 association. Tracking the effects of sickness behaviour on high-resolution dynamic social 25 .

Section: Methodsmentioning

confidence: 99%

Sickness behaviour reduces network centrality in wild vampire bats

Stockmaier

Carter

2020

Preprint

“…5.5 cm in diameter, Figure 1C) connected to a reader (Euro ID LID 665 Multi reader powered by a 12V motorcycle battery). For the second biologging device, we tested two versions of recently developed sensor nodes (part of the BATS wireless biologging network (Duda et al 2018; Ripperger et al 2019c); see Figure 1). These sensor nodes contain an accelerometer, a magnetometer and an air pressure sensor which continuously sampled data and wirelessly transmitted them to a receiver unit.…”

Section: Methodsmentioning

confidence: 99%

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

Duda

Koelpin

et al. 2020

Preprint

Self Cite

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.

“…These timestamps are crucial for post-processing of meeting because they allow accounting for clock drift on the mobile node. We embedded the long-range functionality into the existing modulation scheme using a hybrid phase-alternating modulation on top of the pure amplitude-modulated wake-up sequences of the MN-beacon 45 . As a consequence of the extreme energy limitation of the MN, we ensured the required Signal-to-Noise-Ratio (SNR) by counterbalancing the rate and the desired transmission distance.…”

Section: Methodsmentioning

confidence: 99%

“…As a consequence of the extreme energy limitation of the MN, we ensured the required Signal-to-Noise-Ratio (SNR) by counterbalancing the rate and the desired transmission distance. The combination of the hybrid modulation, the channel encoding procedure 17, 45 and the ‘Telegram-splitting’ technique 16 enables an ultra-low power long-range transmission without additional expenditure of energy. The long-range bursts were received at two long-range receivers, which were deployed on exposed sites (rooftops) at distances of ca.…”

Section: Methodsmentioning

confidence: 99%

Thinking small: next-generation sensor networks close the size gap in vertebrate biologging

Carter

Page³

et al. 2019

Preprint

Self Cite

AbstractRecent advances in animal tracking technology have ushered in a new era in biologging. However, the considerable size of many sophisticated biologging devices restricts their application to larger animals, while old-fashioned techniques often still represent the state-of-the-art for studying small vertebrates. In industrial applications, low-power wireless sensor networks fulfill requirements similar to those needed to monitor animal behavior at high resolution and at low tag weight. We developed a wireless biologging network (WBN), which enables simultaneous direct proximity sensing, high-resolution tracking, and long-range remote data download at tag weights of one to two grams. Deployments to study wild bats created social networks and flight trajectories of unprecedented quality. Our developments highlight the vast capabilities of WBNs and their potential to close an important gap in biologging: fully automated tracking and proximity sensing of small animals, even in closed habitats, at high spatial and temporal resolution.