The 12 June Reviews by R. Kays et al. (“Terrestrial animal tracking as an eye on life and
planet,” p. 1222) and N. E. Hussey et al. (“Aquatic animal telemetry: A panoramic window
into the underwater world,” p. 1221) highlight some challenges to the future of terrestrial and
aquatic telemetry studies, respectively, focusing on issues related to global collaboration and
data sharing. Kays et al. also mention the need to continually improve animal-mounted
sensors to minimize impacts of tags on animals. However, the gaps in our understanding of
impacts associated with attaching instruments to animals are not given substantial
consideration in either Review.