Animal telemetry: Tagging effects.

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.