Protect From Animals
Animals–organisms that range from microscopic to larger than a bus–embody a wide variety of harms to living systems, including other animals. They threaten through predation, herbivory, defense, and parasitism, and they compete for resources such as water, nutrients, and space. Any given living organism commonly faces threats from a variety of animals, requiring strategies that effectively defend from each. Trout and other bony fish, for example, escape predators by having scales made of very thin, flake-like pieces of bone covered with slippery mucus. They also have behavioral strategies such as camouflage, fast swimming, and twisting and turning to achieve release from a predator’s grip.
Send Vibratory Signals
Some living systems use vibrations to communicate, as well as to detect conditions within their environment. Some vibratory signals are very high frequency, such as those of a carpenter bee’s wings that cause flowers to release pollen. Other signals are very low frequency, like those used by elephants to signal to other elephants through the ground. Water, air, and solids present different challenges for transmitting vibrations. Living systems must therefore generate vibrations that move best through the particular medium. For example, a water skipper stands atop water and creates vibrations that circle out from it in ripples, signaling to other skippers to stay out of its feeding area.
