Strange AnimalsFood Chain Builder
Start with a plant and keep asking: who eats this? Every link you add costs about nine-tenths of the energy, which is why lions are rare, grass is everywhere, and no food chain runs much past five links. Pick one of six ecosystems and build one.
What if it disappeared?
Pull one species out of the Serengeti and follow what happened when it really did. Each scenario is a documented case, not a simulation.
Source: Holdo, R. M., et al. (2009). A disease-mediated trophic cascade in the Serengeti and its implications for ecosystem C. PLoS Biology, 7(9), e1000210.
Why chains stay short
In 1942 Raymond Lindeman showed that each feeding level passes on only a small share of the energy it takes in; the rest is burned in movement, body heat and waste. Ten percent is the rule of thumb, real values run from about 2 to 20. After four or five links there is too little energy left to support a breeding population of anything bigger.
Decomposers close every loop
The 90% lost at each step isn't destroyed. Dung, carcasses and dead plants feed bacteria, fungi, termites and dung beetles, which return nutrients to the soil and sea. In the Serengeti, dung beetles bury huge amounts of wildebeest dung, and in the deep ocean whole communities live off a single whale carcass for decades.
Real diets branch everywhere
A chain is a single path through a food web. Spotted hyenas hunt most of what they eat and also scavenge; polar bears take seals but will eat stranded whales and birds' eggs. This tool shows documented predator and prey links only, but every animal here sits in a much denser web.
- Lindeman, R. L. (1942). The trophic-dynamic aspect of ecology. Ecology, 23(4), 399-417.
- Estes, J. A., et al. (1998). Killer whale predation on sea otters linking oceanic and nearshore ecosystems. Science, 282(5388), 473-476.
- Estes, J. A., & Palmisano, J. F. (1974). Sea otters: their role in structuring nearshore communities. Science, 185(4156), 1058-1060.
- Sinclair, A. R. E., Mduma, S., & Brashares, J. S. (2003). Patterns of predation in a diverse predator-prey system. Nature, 425(6955), 288-290.
- Stirling, I., & Archibald, W. R. (1977). Aspects of predation of seals by polar bears. Journal of the Fisheries Research Board of Canada, 34(8), 1126-1129.
Keep exploring
12 other tools, all built on published wildlife data.