Effects of tracking devices on individual birds – a review of the evidence

Abstract

We review long‐term patterns of tracking device use and the reporting of the effects of such devices on individual birds. We assessed > 3400 primary references including > 1500 containing information as to whether effects were looked for and reported. Numbers of papers published increased at 4.4% yr–1. Research on foraging and energetics focussed on seabirds while work on habitat use and dispersal was focussed mainly on landbirds. Migration was the most common study topic overall and increased markedly from the turn of the century in all three bird groups. The proportion of studies reporting effects of devices on individuals declined at > 1% yr–1, while the proportion of studies providing no information on effects increased by ca 0.7% yr–1. The presence of a control group increased the likelihood of a study reporting effects, (45 vs 33%). We modelled the probability of reporting effects separately for three bird groups and two attachment durations. Occurrence of effects was significantly related to attachment method (4 models), year (4 models) and relative device mass (1 model). Invasive attachment methods were associated with a high incidence of effects while tail and leg attachments showed relatively few effects. Probabilities of reporting effects declined over time and increased with relative device mass, however there was no device mass threshold below which effects were not observed. Approaches designed to minimize potential effects of devices on individual birds and to improve scientific rigour have advanced substantially. Nevertheless ca 55% of studies contained no information on potential effects and in many more documentation was inadequate. We call for more systematic documentation of potential effects in peer‐reviewed publications to support more rigorous science and to further improve bird welfare.

The neglected impact of tracking devices on terrestrial arthropods

“…For vertebrates, protocols regarding ethical research methodologies are well adopted and monitored by ethics committees (Drinkwater et al, 2019;Kays et al, 2015). Guidelines for the use and impact assessment of tracking devices for vertebrates are actively being developed and refined (Barron et al, 2010;Geen et al, 2019;McIntyre, 2015;Portugal & White, 2018). While the development of devices for tracking arthropods has sprung from technological knowledge gained from vertebrate research, ethical concerns and guidelines about impact assessment were not co-adopted.…”

“…Furthermore, while the '5% rule', that is, the device mass should be no more than 5% of the animal mass, is often used as a guideline for swimming and flying vertebrates (Aldridge & Brigham, 1988;Kenward, 2000), it has a weak empirical basis and is often disregarded (Barron et al, 2010;O'Mara, Wikelski, & Dechmann, 2014;Portugal & White, 2018). These ethical and scientific drawbacks have resulted in recent guidelines and recommendations regarding the use of tracking devices on birds and mammals (Casper, 2009;Kays et al, 2015;Mcintyre, 2014;O'Mara et al, 2014;Wilson & McMahon, 2006) and a call for more systematic documentation of potential effects (Geen, Robinson, & Baillie, 2019).…”

Backpack-mounted satellite transmitters do not affect reproductive performance in a migratory bustard

“…The use of tracking devices has substantially advanced our understanding of animal ecology and behaviour (Kays et al 2015), allowing unprecedented insight into individual behaviour, movement and population processes (McKinnon and Love 2018). However, tracking devices can negatively affect an individual's reproduction, survival and movements, and have rightly been subject to extensive review (Calvo and Furness 1992;Murray and Fuller 2000;Barron et al 2010;Costantini and Møller 2013;Bodey et al 2018;Geen et al 2019). Such effects vary with study species, transmitter types (GPS/ GSM, GPS-loggers, Argos/GPS PTTs, accelerometers, geolocators), attachment method (glue adhesion, tail-mount, leg-ring, necklace, leg-loop, harnesses) and mass of device relative to the animal (see reviews above).…”

“…Practitioners deploying transmitters clearly want to minimise transmitter effects and often base their methodologies on guidelines, such as the 3% or 5% transmitter relative to body weight 'rule', or use a system that was deemed successful for a similar species. However, recent meta-analyses confirmed that there was no device mass threshold below which effects were not observed (Bodey et al 2018;Geen et al 2019). Furthermore, when extrapolating results of one tagging study to another, similar physiognomies of the target species may not always be enough to predict transmitter effects (Thaxter et al 2016).…”

“…Furthermore, when extrapolating results of one tagging study to another, similar physiognomies of the target species may not always be enough to predict transmitter effects (Thaxter et al 2016). Rather, extrapolations must be approached critically, considering attachment method (Geen et al 2019) and also taking account of the animal's behaviour and circumstances, including foraging strategies (Thaxter et al 2016), seasonal weight changes (Sergio et al 2015), flight mode (Vandenabeele et al 2014;Bodey et al 2018), environment (Bro et al 1999), and age Electronic supplementary material The online version of this article (https://doi.org/10.1007/s10344-019-1332-0) contains supplementary material, which is available to authorized users. at tagging (Petty et al 2004).…”