Species feed on a particular food in a particular way. Animals are designed to effectively gather and use certain foods and evolution has functioned to make them experts. The zookeeper needs to know what the animal has been evolved to feed on and where and how it is gathered. Some animals eat high up in trees, others on or even below ground. Some feed early in the morning, the evening, at night, or all day. Many birds require food throughout the day as their bodies are designed for regular food input. Some animals eat quickly, other animals are slow eaters. Certain species such as the least weasel need feeding several times a day. They will starve if just given one large feed per day. Other animals such as many reptiles eat at extremely irregular intervals.

Whooping Crane seaching for crustaceans at the Calgary Zoo.