Gardener's Delight?

All animals are a tube surrounded or contained by a wide variety of outward structures. The outer structures protect the inner tube and its bits. The food - whatever that is - goes in at one end (we usually call this the front end) and is excreted at the other (back) end, having had all its goodness extracted in its  process through the tube. Some animals - like earthworms - excrete all their waste in one lump, a worm-cast. Others, like birds, excrete the solid matter first and then the liquid matter on top, hence the white topping to bird droppings. I don't think birds have separate exits for solid or liquid waste. We, and many other animals, excrete solid and liquid waste separately. In all cases  the amount excreted is directly in proportion to the intake of food. The more you eat, the more you excrete. No problems so far? Good. Then I'll move on to the next paragraph.

Big animals need a lot of food.  If you have ever kept hamsters or budgies pretending that they are your children's pets, you will know that they eat very little. A cat eats more and a dog even more. Mind you, my point could be made simply by talking about how much a toy dog eats compared to a Great Dane. Elephants eat huge amounts of food - leaves, branches, grass - in order to keep  going. They also drink a lot of water at the same time as they play with mud at waterholes. OK. They plaster mud on themselves to protect from the sun. Primitive sunblock, I suppose. (But no human would ever buy it.) The point is that the more an animal eats, the more it excretes. Obvious, I suppose. But it's still surprising when you see an elephant pee. There is probably enough warm liquid for at least one bath in an  elephant pee. According to Michell Symons Diary 2010 elephants excrete 20 kgs of dung every day. Or 7,300 kg (7.3 tonnes) a year. No doubt a gardener would be pleased to get their hands on this stuff once it was well-rotted. But pity the poor zoo keeper who has to shovel it all up every day. 20kg of elephant dung is the better part of a wheelbarrow full.