On These Islands, Animals Call the Shots

Excerpt from discovermagazine.com

Because of their isolation, islands offer a multitude of ecological opportunities for the creatures capable of reaching them. While many mainland ecosystems are dominated by mammals, islands are environments where insects, reptiles and birds run the show and evolve into fantastical shapes and sizes. 

While many of these evolutionary outliers have gone extinct, islands around the world are still home to fascinating creatures like venomous dragons, pint-sized penguins and armies of amorous crabs found nowhere else on earth. But even these remote islands are being threatened by tourists, invasive species and icebergs run amok. Here are six islands still ruled by animals, despite modern-day dangers:  

Christmas Island 

Each fall, the rocky shores of Christmas Island, an Australian territory south of Indonesia, host one of the world’s greatest natural phenomena: the march of tens of millions of scarlet crabs toward the sea. Sparked by the wet season’s first rains and synchronized to the cycle of the moon, these crabs scuttle across the island — sometimes traversing roads with the help of crab bridges — towards the water to breed.  

Larger male crabs arrive at the beach first, constructing burrows along the shoreline. Once the females arrive, the crabs breed. Then, after a few weeks, the female crabs reemerge brimming with eggs. Right as the high tide begins to recede before dawn, they gather in teeming masses along the waterline. Each female crab releases roughly 100,000 eggs into the surf.

Reaching the water is essential. While adult red crabs are terrestrial and the size of a softball, their offspring are minuscule and aquatic. Of the billions of larvae, only a few offspring return from the waves. The vast majority are eaten by fish or inhaled by immense whale sharks who congregate around Christmas Island each year to partake in the swirling buffet of crab larvae.

Exuma