Parrotfish movement patterns vary with spatiotemporal scale

ABSTRACT: Herbivorous fishes are being increasingly valued for their ecological function in coral reef systems, and consequently they have become the focus of management actions on many reefs around the world. Because many conservation actions require an understanding of the space use patterns of species of interest, there has been an increased effort in recent years to study the movement patterns and home range sizes of many herbivorous taxa. Also of great interest are the fine-scale foraging patterns of parrotfishes and the spatial and temporal scale of their interactions with benthic organisms. In this study, we performed a comprehensive evaluation of the movement patterns of the parrotfish Chlorurus microrhinos at multiple spatial and temporal scales at Palmyra Atoll in 2013-2015. We found that these fish have large home ranges when accounting for migrations to spawning and night refuge sites, but that within feeding territories, their activity is highly non-random and is quite spatially constrained and temporally episodic, indicating a high level of feeding selectivity. These patterns of foraging activity result in the patchy removal of algae from the reef, which may have consequences for the space competition between algae and corals.