Fisheries Behavioral Ecology - Abstracts
Laurel, B.J. and J.A. Brown. 2006. Influence of cruising and ambush predators on 3-dimensional
habitat use in age 0 juvenile Atlantic cod Gadus morhua. Journal of Experimental Marine Biology and Ecology 329:34-46.
Abstract
Predators and prey often co-exist at high densities within the same habitat, yet the behavioural and spatial dynamics underlying
this co-existence are not well known. To better understand small-scale, predator–prey co-occurrence, the spatial patterns and behaviour of age 0 juvenile cod Gadus morhua 75–88 mm SL and two of their known predators, age 2+ cod and short-horn sculpin Myoxocephalus scorpinus, were examined in two habitats (i.e., sand and eelgrass) using three-dimensional video analysis. Both habitat and predator type interacted to result in unique spatial patterns of prey. Spatial overlap between predators and prey was
highest in open habitat in the presence of the cruising predator but lowest in the presence of sculpin in the same habitat. In eelgrass, age 0 cod avoided predators primarily along the vertical axis (i.e., distance off bottom). Age 0 cod stayed above eelgrass in the
presence of sculpin but lowered themselves into the eelgrass while in the presence of predator cod. Anti-predator behaviour (i.e., predator–prey distance, prey cohesion and freezing) was significantly reduced over eelgrass compared to sand, suggesting eelgrass
has lower 'inherent risk' than open habitats. However, predator consumption was similar across all treatments, suggesting that, 1)
complex habitat also impairs the visual cues needed for anti-predator behaviour (e.g., schooling) and assessing the location of
predators, and 2) predators change their behaviour with habitat to enhance their opportunities for finding and capturing prey.
Last updated
26 April, 2007
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