Not seen implemented, but it may work well, examples: Introducing soil with urine/and or feces from animal from opposite sex from the same species, in the enclosure. Introducing leaves/branches/bark with saliva from animal from opposite sex from the same species in the enclosure of browser or plant-eating animal. Introducing hair from pray animal in the enclosure of predator Introducing shower in hot days. Introducing toy snake (or preserved specimen, like plastinated specimen - i personaly worked with plastination of organs and whole animals) in primate enclosure. Introducing whole cut trees with leaves in elephant enclosure. Allowing grass to grow very high, and then releasing animal in the enclosure to investigate in the grass. Introducing hair/feathers from variety of animals, in the enclosure. Giving gorillas imported Aframomum melegueta (protective for cardiovascular system). Giving apes powdered cocoa boiled in water (high on antioxidant, but watch out for oxalates that can be kidney-damaging). Giving apes variety of teas. For reptiles: periodically translocating them in much larger enclosures, snake to can creep fast, to smell different smells, to smell/taste skin from other reptiles (ecdysis), tortoises to go in the grass, hide in growing aromatic tea plants... to experience intense UV-radiation (that normaly exposes to sun, not rainforest reptiles) and heat..
Anybody to know whether there is any zoo in the world giving Aframomum melegueta (''Paradise grape'') to their gorillas, because gorillas in the wild consume this plant and it is believed that is protective for cadriovascular system, particularly for male gorillas (silverbacks, other males..)? It is worth giving for such unvaluable animals like gorillas?
