Brown Pelican - Ecological Success Story
Posted by fareed shakir on May 4th, 2019
The brown pelican (Pelecanus occidentalis) has many claims to fame. It is the national bird of Turks and Caicos Islands, the state bird of Louisiana, a professional diver, and an ecological success story.
It battled back from near extinction in the United States. During the early 1900's brown pelicans could 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 most of the coastal regions of the USA. The key cause of this decline was the pesticide DDT. The DDT was carried into the coastal waters from farm lands and then entered the meals 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 begun 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 for the existence in the waters of the Gulf of Mexico. On April 20, 2010, the Horizon Deepwater drilling rig exploded and caused an oil leak that will be threatening a lot of the wildlife in the Gulf of Mexico including the brown pelican. Since 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 throughout the last 40 years.
The brown pelican is really an amazing bird. It is the tiniest of the pelicans but definitely not a small bird. It's 4 to 5 feet tall and has a wingspan of 6 to 8 feet wide. The beak is approximately a base long and has a large pouch of skin used to scoop up fish and water. The pouch may also be pulsated to permit for cooling during heat of the day. A pelican on land will look very awkward and clumsy but they are magnificent in the air. They could soar and glide low within the water searching for 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 within their pouch. When they come to 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; in fact gulls will lay on a pelican's head awaiting just the right moment to strike. The brown pelican is the sole pelican to be always a diving angler.
Brown pelicans live only in marine waters. They are very rarely found inland. All of the time, they are found within 20 miles of the shore. They prefer bays and other shallow marine waters. These birds are extremely gregarious nesting in flocks of male and female year round. They build nests on islands. They nest on a lawn or in the low lying branches of trees or bushes if predators are nearby. They mate for life.
Brown pelicans have been experiencing a lost of nesting sites as a result of coastal erosion. There have 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 is currently threatened again by the Gulf of Mexico oil spill. The brown pelicans'way of life helps it be very vulnerable to this oil spill. The oil spill can affect these birds in these ways.
1. While they dive into the water to eat, they dive into and through the oil which coats their feathers. Depending on how much oil is on the feathers they might be at the mercy of hypothermia or even drowning. kontejnerji
2. Ingesting oil or oil contaminated fish might cause sickness or death for these birds.
3. Even if the oil doesn't cause harm to these pelicans, it may cause a decrease in the fish available for food. Since adult pelicans can eat as much as 4 pounds of fish each day, any lessening of the foodstuff supply might lead to great injury to the flocks.
4. Because it is Spring, pelicans and many other birds and marine life are producing offspring. Some pelican eggs have been found with oil smudges. Scientists don't know very well what the effectation of the smudges may be. The egg shells are porous to be able to allow 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 go through the egg shell and cause almost certain death to the embryo.
6. Once the embryos are born they will face the exact same threats from oil and oil contaminated fish that their parents face - only they will be much weaker and smaller.
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About the Authorfareed shakir
Joined: February 28th, 2019
Articles Posted: 669
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