0% through the cycle — watch the two chase each other
Predators and prey rise and fall in step — more rabbits feed more foxes, more foxes thin the rabbits, and round it goes. Pull the predators out and watch the prey run away with it.
Now reason backwards — tap a card to reveal the ecosystem story
Graziers shoot out the dingoes across a region. A few years on, the ground is bare and small native mammals have crashed. What happened?
Tap to reveal
Dingoes were the brake at the top. Remove them and kangaroos and rabbits boom and strip the plants bare, so the soil erodes; meanwhile foxes and feral cats, which dingoes used to suppress, run unchecked and hammer the small native mammals. Pull out the top predator and the whole web below runs wild — a top-down collapse.
Cane toads were brought in to eat cane beetles. Instead, quolls, goannas and snakes have vanished from huge areas. How?
Tap to reveal
The toads barely ate the beetles, bred in their millions and spread — and they're poisonous. Native predators that tried to eat them died. So a species was ADDED that the web had no way to control, and the predators it poisoned dropped out, shifting everything those predators used to keep in check. The textbook lesson in not adding a species and assuming it'll behave.
A creek's native fish are dying off, yet the water tests perfectly clean. Where do you start looking?
Tap to reveal
Reason up and down the web, not just at the water. Maybe the insects the fish eat have collapsed (a producer or plant lower down was cleared), or a new predator was introduced upstream, or something removed the shade and the water warmed. A crash always has a cause sitting somewhere in the web — trace the feeding threads back from the fish until you find the broken link.
A national park bans hunting to protect the kangaroos. A decade later the grassland is degraded and other species are struggling. Why?
Tap to reveal
With nothing thinning them, kangaroo numbers climbed past what the grassland could feed. Too many herbivores overgraze the producers, the plants can't recover, and the animals that relied on that grassland — for food or cover — lose out too. Protecting one species without its predators can tip the very web you were trying to save. Balance, not just kindness.