To stand silently observing Little Cayman’s seemingly desolate Booby Pond is to feel transported to an almost primitive age. As the sun fades, leaving only stark silhouettes over the inky darkness of the water, one stands in wonder as the primal battle for life is played out in the skies overhead. The National Trust’s Booby Pond Nature Reserve is home to the largest breeding colony of Red-footed Boobies in the Western Hemisphere. These birds are Little Cayman’s original deep-sea fishermen. Like our ancestors who roamed the seas in schooners in quest of bounteous fishing grounds, Red-footed Boobies fly for, sometimes, days in search of food. However, at the end of a hard day’s toil, their troubles are far from being over. For as they draw near the waters of home, they know that they will inevitably face one final challenge from their archenemies, the Magnificent Frigate bird.
Whereas our Red-footed Boobies are thought to roam as far as the Southern coast of Cuba or even possibly the Western end of Jamaica in their daily quest for food, Frigate birds tend mainly to hang around close to shore. They are Little Cayman’s airborne pirates, relying on their superior agility and strength to hijack returning Boobies and steal their catches.
February is peak nesting time for Red-footed Boobies who nest amongst the branches of mangroves and forest trees in the nature reserve. With both parents alternating responsibility for incubating eggs and feeding the downy chicks upon hatching, this means that one adult will stay on the nest while the other leaves in search of food. Boobies have a storage area called a ‘crop’ in their gullets where they hold food that will later be regurgitated to feed their chicks and mate. Unfortunately, patrolling Frigate birds are all too aware of this fact and see this as the perfect ‘easy meal’. In one-on-one combat between a Booby and Frigate bird, the latter will always win. The only option for the Booby is to lighten its load by purging the contents of its crop, and to head back out to sea to find more food, leaving its mate stranded and its chicks hungry.
However, if Boobies are deficient in strength, they are superior in intellect; for Little Cayman’s deep-sea fishermen have devised an ingenious line of defense to confuse the Frigate birds based on the premise that there is safety in numbers. Their dawn exodus from the nesting site, as they embark upon their lengthy journeys, proves unproblematic as they are without a catch. It is the return journey where they will need to outwit their enemies. For energy efficiency, Red-footed Boobies can be seen flying low over the ocean. As they near home, they mill around offshore until they have formed a group – the larger the group, the less chance there is of becoming a victim. The Boobies begin to climb in a spiraling column, joined constantly by birds arriving from out at sea. This ascent will allow them ultimately to use gravity to give them optimum speed for their final descent into the nest. Gradually, they peel off in large groups from the top of the column, wings are streamlined and, torpedo-like, the Boobies begin their controlled free fall into the safety of their nesting grounds.
When one considers there are in the region of 20,000 Red-footed Boobies in Little Cayman, it is easy to understand the astonishing spectacle this battle for survival must make in the encroaching twilight hours. Their technique must work, as recent studies indicate that the Red-footed Booby population is healthy, with an increase from 3,155 to 4,839 nesting pairs over an eleven-year period from 1986 to 1997. That is not to say, however, that the future holds no concern for these wondrous birds. The threat of explosive development on Little Cayman over the past few years may soon put a severe strain on the island’s natural resources.
So, next time you are fortunate enough to be near Booby Pond Nature Reserve at sunset, spare a thought for the plight of the Red-footed Boobies as they prepare to battle their way home to their chicks.
Source: Cayman Islands National Trust