Advances in biologging science: a review of bird studies

Abstract

As birds are a highly mobile group of animals, it is often difficult to obtain physiological, behavioural or ecological information from individual birds under natural conditions. To help address the difficulties of studying free-living animals, biologging technologies that use small 'animal-borne' recording devices have been developed. The technology started in the 1970s from simple time-depth recorders, and it has revealed the amazing diving abilities of seabirds. Now, the diversification and miniaturization of biologging devices offers unique opportunities to study various biological aspects of marine and terrestrial bird species. In this review, we explore recent advances in biologging technologies and its application to bird studies in the following major research themes: movement, foraging, biomechanics, physiology, cognition, social behaviour and external environment. Research highlights include the documentation of long-distance migratory movements, foraging strategies, optimized biomechanical output, energy-saving mechanisms, cognitive abilities, social interactions and environmental relationships over a wide range of bird species. Then, we discuss the current challenges and future directions in this field; the refinement of devices and attachment/retrieval methods; the development of analytical techniques suited for spatially- or temporally-correlated data; the incorporation of other individual-based research techniques, and the enhancement of multi-disciplinary studies. The scientific field of biologging will help integrate diverse research disciplines such as biomechanics, physiology, behaviour and ecology, to better understand the life of birds in their natural environments.