Over the last several decades, advances in telemetry have greatly expanded our ability to track where sharks go and when, but are limited in their ability to provide insights into specic behaviors or reasons for using particular habitats. Until recently, the study of wild elasmobranch movements and habitat use has largely been limited to quantifying movements via acoustic or satellite telemetry (see reviews by Nelson, 1990; Sims, 2010; Sundstrom et al., 2001); however, despite advances in these techniques, results of movement studies often remain disconnected from the behavior and physiology of the animal being tracked. Because of this, researchers have often inferred behavior from horizontal or vertical movements without the ability to test these assumptions empirically. Although brief, direct observations of elasmobranch behaviors are possible in a few cases, we generally lack data on their daily activities even when we may have weeks or months of information about their movements. Due to technological limitations many important questions about elasmobranch behavior have gone unaddressed: When are animals most active? When do they rest? How often do they feed? How often do they mate? What is the energetic cost of different behaviors, and how does this determine where and how they spend their time?.
