Energy Loss in Food Chains

Respiration and heat loss

Organisms use the energy from their food for respiration. Allows them to produce ATP for growth, movement, and other life processes. During respiration some energy is lost as heat. This is especially true in warm-blooded organisms that must maintain constant body temperature.

Movement

Use lots of energy for hunting, running, flying, etc. This reduces amount of energy available to the next trophic level.

Excretion and Waste (Egestion)

Not all energy is absorbed/fully digested. Some of it is lost as feces (egestion). E.g, undigested plant material such as cellulose in herbivores.

Excretion and Waste (Excretion)

Some energy is lost in urine (excretion) in the form of waste products like urea.

Death and decomposes

When organisms die, their energy is not directly transferred to the next trophic level. The energy is used by decomposers (e.g, bacteria and fungi). They break down dead matter and recycle nutrients into the ecosystem.