Natural History Wanderings

ScienceDaily reported on a study by Chinese researchers on the function of sheaths on orchids. Many orchids have sheaths or bracts (modified leaves) whose function was unknown. In studying the orchid Coelogyne rigida the researchers found that the sheaths served as landing platforms that helped attract, secure and position foraging sunbirds, Aethopyga gouldiae. This facilitated the collection and dispersal of pollen as it attached to the birds beaks and created effective cross-pollination and fruiting. When the sheaths were removed, sunbirds visits were significantly less frequent and shorter. Read more at ScienceDaily Orchid adding bird perch for crossing ensures reproduction.