4.1 Has there been a shift in the number of frugivorous
tracking studies?
Seed dispersal and movement ecology are increasingly integrated, and the
use of tracking technology to study frugivorous species has
significantly increased in the past 17 years, from 33 studies between
1978 - 2004 to 129 studies from 2005 – present. The number of studies
calculating seed dispersal distances from frugivore movement increased
from 8 studies in 1988 – 2006 to 59 studies from 2007 - present (Fig
1).
Radio tracking was the most commonly used tracking method for frugivores
up until 2017, but since then, GPS tags have become the most used
method. These increases are likely associated with the advancement in
tracking technology and specifically, the reduced costs and increased
availability of tags (Kays et al, 2015; Pimm et al, 2015). The
smallest commercially available GPS tag in 2006 was 9.5g
(Microwave Telemetry Inc, 2021) whereas now tags weighing
< 3g are commercially available from numerous companies (e-obs
GmbH, 2021; TechnoSmart, 2021). In addition, an increasing number of
interdisciplinary teams are constructing GPS tags using commercially
available components (Allan et al, 2013; Fischer et al, 2018; Paden &
Andrews, 2020). These tags tend to be cheaper than traditional tracking
devices, potentially increasing the number of research studies that have
access to tracking technology. The potential for remote data download,
ongoing battery miniaturisation and implementing solar-powered recharge
capabilities have enhanced our ability to monitor species across greater
distances, in remote locations, and across diverse landscapes, where
previous attempts failed (Bouten et al, 2013; Hart et al, 2020; Shimada
et al, 2020).