Last month, we wrote about the common myth that Brown Pelicans and the Caribbean subspecies, pelicanus occidentalis occidentalis, go blind from the trauma of diving for food and, as a result, starve to death. Nature has padded the Brown Pelican’s body with air sacs that cushion his striking the water. While we watch the large, cumbersome-looking bird hit the water and laugh at what appears to be a belly flop, the Brown Pelican is an engineering marvel that has changed very little during his 40 million years on earth.
As stated in last month’s article on Brown Pelican Facts, Browns do go blind but the causes do not include the fact that they dive for food. All eight pelican species, including our Caribbean Brown Pelican, face ever-increasing threats of injury and death attributed mainly to the activities of man. A few are taken by sharks and orcas and, most certainly, they are killed during natural disasters. However, the main threat is man.
Some 20 years ago, a Brown Pelican befriended my son during a week of fishing in Florida. We named the pelican Pete and every day Pete sat on a rock next to my son. A wildlife officer informed us that Pete was a once-wild pelican who had been severely injured when he dove for a fish that was attached to a board, smashing his long beak and breaking a wing as his tormentors watched from a boat and laughed. After extensive surgery and a long recovery period in a bird sanctuary, Pete was released only to take up residence at the park, never to join a wild flock or fly again.
As with all bird species that depended upon water, the Brown Pelican population was in serious jeopardy during the 1960 to 70s, due to the uncontrolled use of DDT. In some areas, the Brown Pelican disappeared completely; a result of direct poisoning as well as the DDT-caused thinning of egg shells preventing reproduction. With bans on DDT and dedicated efforts to reintroduce the pelicans, they are once again in residence in their historical territories and seem to be thriving.
However, all does not bode well for the pelican, neither here nor anywhere around the world. Other chemical threats have replaced DDT. Nitrates from fertilizers wash into the rivers and seas at an ever-increasing rate. The introduction of nitrates, along with other catalysts such as raw sewage, provides nutrients for uncontrolled algal blooms that leech oxygen from the water stressing the fish upon which the pelicans feed. The fish become ill with botulism caused by the bacteria clostridium botulinum. Within hours of eating an infected fish, pelicans suffer paralysis, blindness, and often death.
Rampant coastal development has destroyed traditional pelican rookeries, i.e. nesting sites; some of which used to contain thousands of nests. Aside from the obvious physical destruction of once wild areas, those developments alter the natural flow of water along shores and cause settling of sediment on close-in reefs, thus destroying critical fish nurseries, critical not only to the pelicans’ livelihood but also that of marine species as well as fishermen whose income depends upon healthy fish stocks.
Irrespondible fishing, both recreational and commercial, also poses a threat to pelicans and other birds dependent upon the sea. How often do we see fishermen throwing spoiled bait fish into the sea or tangles lines cut and thrown into the sea or along side beaches? Spoiled fish can be deadly to birds that feed upon fish. Improperly discarded tackle kills, often slowly when the bird cannot free itself or ingests a hook.
Imagine your next meal is poisoned with botulism but you do not know. Imagine going to the market to find it covered in mud and silt and there is no food. Imagine you dive to eat but you cannot eat because your mouth is tied shut and you have no help.
Visit Part I of this series on Brown Pelicans – Myths and Facts Part I or a cruiser’s tale of The Brown Pelican’s Mouth can Hold More than its Belly!