ABSTRACT
There are several acceptable approaches to keeping animals. Six can be usefully distinguished, though they overlap.
Natural and/or free-living conditions
For some animals we can create artificial habitats that are probably no different, so far as the animals are concerned, from their natural ones. In some cases stocking is unnecessary because the animals just arrive. Examples are ponds for wildfowl, such as those of the Emperor Frederick II, or of Sir Peter Scott and the Wildfowl and Wetlands Trust. Some of the wildfowl will arrive in the course of migration. Artificial ponds can probably be even more the real thing for freshwater invertebrates, as well as amphibians and fish. Diving beetles and the like arrive of their own accord, once a suitable pond has been created.
