Loud shrieking calls and the pungent smell of droppings from thousands of Cape gannet birds greet visitors to the Lambert's Bay Bird Island nature reserve off South Africa's west coast.

Each gannet cries a unique call as it circles the island searching for its mate in a colony of about 12,000 birds. The white gannets with yellow crowns crowd the beach, flapping their black-tipped wings. There are a few are from the Australasian and Northern gannet families. The gannets share the island nature reserve with a colony of about 1,500 seals, according to tour guides.

Lambert's Bay Bird Island is one of only six breeding spots for the gannet, said tour guide Yiseman Nompondo. Every spring, the birds come to the island to lay their eggs. Each female lays a single egg in a nest made of dried droppings. The chicks are born blind, naked and black. By three months, with their feathers full and their striking blue eyes open, the gannet chick is kicked out of the nest. As winter approaches, the birds prepare to fly to southern Africa's warmer east coast, flying toward Mozambique, said Nompondo.

Nompondo leads tourists from South Africa's mainland, across the breakwater to the 7.5 acre island. Visitors come from the United States, Europe, Asia and other parts of Africa, to see the migratory birds.

"Each and every year, they come in numbers, in a set or group," he said, adding that tourists excitedly take photographs of the gannet colony from within a hide, giving them their own bird's eye view of the gannet colony.