Intraguild processes drive space-use patterns in a large-bodied marine predator community

Interspecific interactions, including predator-prey, intraguild predation
(IGP), and competition, may drive distribution and habitat use of predator
communities. However, elucidating the relative importance of these
interactions in shaping predator distributions is challenging, especially
in marine communities comprising highly mobile species. We used
individual-based models (IBMs) to predict the habitat distributions of
apex predators, intraguild (IG) prey, and prey. We then used passive
acoustic telemetry to test these predictions in a subtropical marine
predator community consisting of eight elasmobranch (i.e., shark and ray)
species in Bimini, The Bahamas. IBMs predicted that prey and IG prey will
preferentially select habitats based on safety over resources (food), with
stronger selection for safe habitat by smaller prey. Elasmobranch
space-use patterns matched these predictions. Species with predator-prey
and asymmetrical IGP (between apex and small mesopredators) interactions
showed the clearest spatial separation, followed by asymmetrical IGP among
apex and large mesopredators. Competitors showed greater spatial overlap
although with finer-scale differences in microhabitat use. Our study
suggests space-use patterns in elasmobranchs are at least partially driven
by interspecific interactions, with stronger spatial separation occurring
where interactions include predator-prey relationships or IGP.