The creamy white beaches of the tropics are made of millions of tiny shell and coral fragments, ground down by gnawing fish and pulverising waves. The granite (1) that forms the bulk of the island weathers very slowly and adds little to the beach sand. The tide wash brings in stranded plankton, food for the crabs such as Horn-eyed Ghost Crabs (2) that forage along the tide line. Their breeding burrows create tiny sandcastles all along the beach. Here, too, over-wintering shorebirds from the Arctic, gather to feed. The Whimbrel (3) will catch and eat the crabs if it can. Whimbrel, Ruddy Turnstone (4) and Grey Plover (5) all breed in the Siberian tundra and escape the northern winter by flying south to the tropics. The Crab Plover (6) is more unusual; this extraordinary wader breeds in burrows! Outside the breeding season it is found only along the East African and Indian Ocean island coasts. Out over the turquoise reef lagoon, seabirds are swirling, among them the Sooty Tern (7) with black wings and white underparts which can look blue from the reflection of the sea. The FairyTern (8) lays its single egg on tree branches. The Hawksbill Turtle (9) nests between September and March, females coming ashore to lay their eggs. The sea washes up floating seeds which eventually colonise the upper beach. First among beach crest plants is the Beach Morning Glory (10) a sprawling plant with magenta flowers. This may then trap a floating coconut, which, if it germinates, will become part of the coastal woodland. Coconuts (11) often lean towards the sea as if to help their falling nuts to reach the water. Many local trees are dispersed by water; their floating seeds regularly turn up on the strand line. Part of the beauty of the beach is the wonderful variety of shells (12), but please do not collect them - the hermit crabs use them as mobile homes. On the beach crest grow a few crooked bushes of Tree Heliotrope or Bwatabawith grey-green silky-haired leaves (13).