Brown Pelican - Ecological Success Story

Posted by fareed shakir on May 4th, 2019

state bird of Louisiana, a specialist diver, and an ecological success story.

It battled back from near extinction in the United States. During early 1900's brown pelicans might be found from over the Atlantic, Pacific and Gulf of Mexico coasts - from California to Chile and from Maryland to Venezuela. However, by the 1960's this bird had disappeared from Louisiana, the pelican state and from the majority of the coastal aspects of the USA. The main reason behind this decline was the pesticide DDT. The DDT was carried into the coastal waters from farm lands and then entered the food chain. As these pelicans ate tainted fish, they laid eggs with thin shells. Since brown pelicans incubate their eggs by holding the them under their webbed feet rather than against their breasts, the eggs would break from the weigh of the parents. After DDT and similar pesticides were banned in the 1970's, the brown pelican population started initially to recover. From 1970 until 2009 the brown pelican was on the endangered species list.

Just months after being removed from the endangered species list the brown pelican is again fighting because of its existence in the waters of the Gulf of Mexico. On April 20, 2010, the Horizon Deepwater drilling rig exploded and caused a fat leak which can be threatening much of the wildlife in the Gulf of Mexico including the brown pelican. Because this bird depends on the waters of the Gulf for food and the barrier islands for nesting areas, this ecological disaster could reverse their wonderful recovery over the last 40 years.

The brown pelican is really an incredible bird. It is the smallest of the pelicans but not really a tiny bird. It's 4 to 5 feet tall and has a wingspan of 6 to 8 feet wide. The beak is about a base long and has a very large pouch of skin used to scoop up fish and water. The pouch can also be pulsated to allow for cooling during the warmth of the day. A pelican on land will look very awkward and clumsy but they're magnificent in the air. They could soar and glide low on the water trying to find fish.

The brown pelican is a good angler. The pelican flies throughout the water trying to find menhaden, herring, mullet, sheepshead, silversides and other fish. When fish are spotted, they dive head first to catch their food and net both fish and water in their pouch. If they arrived at the outer lining, they drain the water from their pouch and swallow the fish. Gulls sometimes attempt to steal fish from the pelican's pouch; actually gulls will sit on a pelican's head looking forward to just the right moment to strike. The brown pelican is the sole pelican to become a diving angler.

Brown pelicans live only in marine waters. They're very rarely found inland. Most of the time, they are found within 20 miles of the shore. They prefer bays and other shallow marine waters. These birds are very gregarious nesting in flocks of male and female year round. They build nests on islands. They nest on a lawn or in the lower lying branches of trees or bushes if predators are nearby. They mate for life.

Brown pelicans had been suffering from a lost of nesting sites because of coastal erosion. There has been some efforts to rehabilitate prime nesting areas. The elimination of DDT and the restoration of their nesting sites made the brown pelican a genuine ecological success story.

The brown pelican has become threatened again by the Gulf of Mexico oil spill. The brown pelicans'way of life causes it to be very vulnerable to the oil spill. The oil spill make a difference these birds in the following ways.

1. As they dive into the water to eat, they dive into and through the oil which coats their feathers. Depending on what much oil is on the feathers they might be susceptible to hypothermia or even drowning. ekološki otoki

2. Ingesting oil or oil contaminated fish may cause sickness or death for these birds.

3. Even though the oil doesn't cause harm to these pelicans, it might lead to a decrease in the fish readily available for food. Since adult pelicans can eat as much as 4 pounds of fish each day, any lessening of the foodstuff supply could cause great injury to the flocks.

4. Because it is Spring, pelicans and a number of other birds and marine life are producing offspring. Some pelican eggs have already been found with oil smudges. Scientists don't understand what the effect of the smudges may be. The egg shells are porous in order to permit the embryos to change carbon dioxide for oxygen. If there is enough oil on the shells the embryos could suffocate or suffer significant damage from the oil.

5. Volatile organic compounds (VOC), oil's toxic components, could pass through the egg shell and cause almost certain death to the embryo.

6. When the embryos are born they'll face the exact same threats from oil and oil contaminated fish that their parents face - only they'll be much weaker and smaller.

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fareed shakir

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fareed shakir
Joined: February 28th, 2019
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