Abstract
Monitoring animals with electronic tags is an increasingly important tool for fundamental and applied ecological research. Based on the size of the system under study, the ability to recapture the animal, and research medium (e.g., aerial, freshwater, saltwater, terrestrial), tags selected may either log data in memory (bio-logging), transmit it to a receiver or satellite (biotelemetry), or have a hybrid design. Over time, we perceive that user groups are diverging based on increasing use of technology specific terms, favouring either bio-logging or biotelemetry. It is crucial to ensure that a divide does not become entrenched in the community because it will likely hinder efforts to advance field and analytical methods and reduce accessibility of animal tracking with electronic tags to early-career and new researchers. We discuss the context for this emerging problem and the evidence that this is manifesting within the scientific community. Finally, we suggest how the animal tracking community may work to address this issue to maximize the benefits of information transfer and integration between users of the two technologies.
Background
Electronic tagging of free-ranging animals has transformed our understanding of their movements, behaviours, physiological capabilities, and ecological interactions, providing a powerful means for identifying and improving conservation practices (Hussey et al. 2015; Kays et al. 2015; Lennox et al. 2017). Two different types of electronic tags have been developed for animal tracking: those that log data onboard and those that transmit data to an external receiving station. Loggers have the advantage of recording at constant or frequent time intervals, features of the environment (depth/altitude, temperature, sound, salinity, ambient light), or internal state of the animal (heart rate, acceleration, internal temperature), but require physical recovery by researchers to access data onboard (Rutz and Hays 2009). Transmitters overcome the limitation of physical recovery by communicating data remotely to receivers. The data transmitted by these devices (including optional temperature, acceleration, depth, conductivity, or predation sensors, among other parameters), are often at a lower temporal and spatial resolution and only collected when tagged animals are within range of receivers (Cooke et al. 2004; Hussey et al. 2015) or greatly compressed to enable data transmission (Harcourt et al. 2019).
Devices that either log or transmit data have been coarsely organized into the subfields of bio-logging and biotelemetry, both of which have been applied to a range of fundamental and applied research questions across animal taxa and environments. Cooke et al. (2004) defined biotelemetry as “remote measurement of physiological, behavioural, or energetic data,” essentially identical to how Rutz and Hays (2009) defined biologging “use of miniaturized animal-attached tags for logging and/or relaying of data about an animal’s movements, behaviour, physiology and/or environment.” The technical differences between the electronic platforms seems to be driving a division between users of the two technologies within animal tracking science. Our team (comprised of a diverse, globally dispersed group of researchers whose research interests span the aquatic and terrestrial domains) has perceived a persistent and potentially growing divide between users of devices that log data and users of those that transmit data, and we hypothesize that this is connected to social/professional networks around each technology type associated with studies of certain animal taxa and ecosystems. This separation is leading to a divergence of specialized language reflecting the use of the two technologies. Should this divide continue to widen, we predict that researchers might limit their choice of tagging technologies to those favoured by their subfield, when really the choice of tools should be driven by the specific needs and challenges of the research agenda. Ensuring that there is but a single community of users of electronic tags is important to advance the discipline of animal tracking, improve and integrate the science conducted, and enable a deeper understanding of fundamental and applied ecological phenomena.
In this perspective, we address this divergence within the animal tracking community and make a case for proactively working towards increased unity between biotelemetry and bio-logging. In so doing, we hope that we can foster the goals of integration, inclusivity of users, and scientific advancement championed by the conferences, journals, and societies developed to connect animal tracking scientists. We acknowledge that the ideas presented here reflect our lived experiences and thus others in our community may have different experiences, perceptions, and opinions. We suggest that semantics are crucial to addressing this divergence, because within what we perceive as two separate communities, we suggest each is of the opinion that the technology that they use more frequently, biotelemetry or biologging, is the “umbrella” term representing the whole community of electronic tag users. We hope that this opinion piece will stimulate discourse on what we regard as a troubling issue.
