Satellite imagery can be used to quickly map indirect effects of the predator-prey relationship on the animals' habitats, an Australian researcher says.

Freely, available satellite photos of the Earth's surface allows scientists and researchers to examine landscape features, such as lagoon habitat at Heron Island, located within Australia's Great Barrier Reef, that Elizabeth Madin said she and her colleagues at the University of Technology in Sydney in a paper published online in Scientific Reports this week.

Results reveal distinct patterns of grazing halos -- rings of substrate without seaweed -- within the algal beds surrounding coral patch reefs. Scientists had attributed grazing halos to fish and/or urchin organisms that eat plants. The organisms are thought to hide from predators within the reefs and then forage for food in an expanding radius

Madin said her team's work indicates herbivores' anti-predator behavior can shape vegetation distributions on a scale visible from space. By comparing sequential Google Earth images of specific locations over time, the technique could provide a quick and inexpensive way to monitor the,indirect effects of predator removal, recovery and reintroduction on landscapes nearly anywhere on Earth.