Trends and Perspectives in Animal-Attached Remote Sensing

Abstract

T here are two primary methods of studying animals in the wild: observation from a distance, and observation of the animals from their own perspective. The former is the standard choice; this reflects our bias towards vision, our primary sense, and is illustrated by visual observation studies of nature going all the way back to Aristotle. This approach is common even today, although now the shortcomings in our visual capacity can be enhanced by technologies ranging from photography through infrared cameras, videos, and night vision devices to radar, echolocation, and hyperspectral scanners (Amlaner and McDonald 1980). Irrespective of the type of aids used to "observe" animals remotely, these studies are always hampered by elements that can come between the observer and the study animals (eg undergrowth, clouds, water, etc); in each case, the effects are exacerbated by distance and ultimately lead to range limitations.Telemetry (from the Greek tele, far, and metros, measure-ment) is a branch of science that seeks to eliminate such limitations, although in reality the first classic telemetry studies (using radio telemetry; Amlaner and McDonald 1980) were also range limited. In its ultimate form, however, this approach has no range limits, since both the sensory and recording systems are attached to the animal itself. This form of animal-attached remote sensing has recently been termed "bio-logging" (Naito 2004), a combination of the terms "biology" and "logging", the latter being derived from the old term "ship's log", where data were stored. The physical contact between the logging device, or recording tag, and the study animal allows the sensors to collect dataon a multitude of parameters, including heart beat frequency, skin humidity, and breathing rates, none of which are accessible by visual observation. Given the huge datastorage capacity available today, multiple variables can now be assessed simultaneously at rates of many times per second, to acquire millions of data points describing the biology of free-living animals over a wide range of time periods. In other words, bio-logging allows scientists in the field to record complex quantitative measurements from animals that are behaving completely naturally. First stepsHistorically, there have been four important conceptual stages in the development of bio-logging. The first stage involved the realization that animals can carry foreign objects attached to their bodies. This probably dates as far back as the origin of domestication, to the time when pack animals were first used. The second stage was reached when, for the first time, a device capable of transmitting information was attached to an animal to monitor something related to the animal itself. To the best of our knowledge, this occurred when 437 Animal-attached remote sensing, or bio-logging, refers to the deployment of autonomous recording tags on free-living animals, so that multiple variables can be monitored at rates of many times per second, thereby generating millions of data points over period...

Short-term effects of tagging on activity and movement patterns of Eurasian beavers (Castor fiber)

“…Awareness of tagging-induced effects is not only important for the sake of animal welfare but should also be considered to prevent biased research results (Dechen Quinn et al 2012;Ropert-Coudert and Wilson 2005). In particular, determination of effects which occur immediately after releasing the animal is important for researchers working with relatively short-term datasets.…”

“…The general premise is that such tags allow free-living animals to be studied with Electronic supplementary material The online version of this article (doi:10.1007/s10344-016-1051-8) contains supplementary material, which is available to authorized users. only minor disturbance Ropert-Coudert and Wilson 2005) and minimal observer effects (Cagnacci et al 2010) while delivering insights into animal behaviour and ecology (Shillinger et al 2012;Weimerskirch 2007) with potential implications for conservation and management actions (Schofield et al 2007;Wilson et al 2015).…”

First known satellite collaring of a viverrid species: preliminary performance and implications of GPS tracking Malay civets (Viverra tangalunga)

“…Furthermore, GPS hardware is currently more expensive than VHF transmitters (Rodgers 2001). This high initial cost can pose a logistical barrier to projects, and researchers must not sacrifice statistical power in the blind pursuit of advanced techniques.…”

“…However, the universal application of GPS to wildlife tracking is still limited by technological constraints, as historically, both transmitters and batteries have been bulky and large (>400 g, some up to 2.2 kg) (Rodgers 2001). Most terrestrial GPS studies have focused on mammals >7 kg, so spatial research on small and medium-sized species relies on VHF transmitters (Blackie 2010;Cagnacci et al 2010).…”

“…This development meant the collection of larger, more consistent, fine-scaled and accurate datasets (Rodgers 2001;Kochanny et al 2002). Satellite tracking minimizes logistical effort and eliminates the influence of observer presence on recorded behavioural patterns, generating datasets otherwise unobtainable by VHF tracking and more relevant to conservation actions (Hebblewhite and Haydon 2010).…”