researchers say that sand from the beaches of the northeastern us and Canada have been making its way to Bermuda. They believe that this has been due to the curious appetites of migratory birds which carry quartz crystals to the island in their stomachs.
Palaeontologist Bruce Rueger of Colby College in Waterville, Maine, was studying deposits from the bottom of a pond called Lover's Lake for clues to Bermuda's climate when he came across the grains of crystalline quartz. The volcanic rocks below Bermuda contain too little silica to form quartz crystals. The nearest sources of quartz are North American beaches, and Bermuda lies along major bird migration routes from the northeastern us and Canada. This led Rueger to think that birds might be bringing the quartz to the island. Many birds ingest grit, partly to aid in digestion. To check this, Rueger went to a local museum and found that the gut contents of the migratory birds had quartz grains. Each bird had only 23 to 89 grains, so Rueger says that the average delivery must have been about 15,000 to 62,000 "bird loads' each year.