Experimental demonstration of a trophic cascade in the Galápagos rocky subtidal: Effects of consumer identity and behavior
Fig 5
(A) Observed and model-fit pencil urchin survivorship during the initial 20.5 hours of the TC experiment and (B) consumer co-occurrences during initial 21 hours of the 8 day pencil urchin TC experiment (11:46 until ~ 09:00 the next morning) when blunthead and finescale triggerfish were present. All of the exposed urchins in the predator access treatments were eaten by blunthead triggerfish (Fig 4C). Inset graph shows the same survivorship results plotted on a logarithmic scale to show the occurrence of triggerfish, hogfish and top-predators (sharks and sea lions). (B) Data points represent the first time point that a species was observed in the time-lapse record (entrance time in seconds, y axis) as an indicator of consumer species overlap. Actual consumer residence times are presented in Table 2. Predator images below the x-axis represent hogfish, blunthead triggerfish, finescale triggerfish, Galápagos sharks, hammerhead shark, sea lions, yellow bellied triggerfish, green turtles, and white tip sharks (from left to right).