Sisal nesting logs are made from an Agava sisalana, a native plant to Central America. The sisal plant has become a nuisance in South Africa, spreading across the land. After the sisal plant has flowered and set seed, it dies, and leaves behind the stalks – these become the perfect shelters for nesting birds. A listy of birds that can be expected to nest in the sisal log: Barbets Cardinal Woodpecker Cape Glossy Starling Green hoopoes Grey Hornbills Sparrows