Trees within or near animal enclosures are regularly inspected, trimmed or felled as necessary to avoid animals being harmed by falling branches, toxicity, or trauma.
c. Access to very tall trees which are useful for shade limited by electric wires, barriers etc. to prevent their being damaged by the rhinos, hippos or tapirs.
d. Any natural materials (e.g., plants and their products, such as seeds or fruit) are assessed for toxicity to the species held before use.