Oh look it's even worse: only about 10% of intake energy is fixated (plant matter -> meat) in the next trophic level.

https://en.m.wikipedia.org/wiki/Ecological_efficiency

Wikipedia says ATP generation alone loses 60% of energy regardless if ecto- or endothermal organism. ATP is the energy curency of life. So 60% of energy lost, before any synthesis, signaling, membrane transport, ... even happened.