Gulf oil spill thought to have killed some 60,000 birds

Brown pelican being released after being cleaned of oil in the Gulf of Mexico.

On April 20, 2010 an explosion on the BP-owned Deepwater Horizon oil rig in the Gulf of Mexico initiated the world's second-largest oil spill and killed 11 people. For weeks, scientists and engineers struggled to contain the millions of gallons of crude oil spewing from the open well more than 5,000 feet below the surface of the sea. In the months it took to cap the well, more than 4.9 million barrels of oil, or more than 200 million gallons, had leaked into the Gulf.

200 bird species affected
Some of the most heart-wrenching images that appeared during the spill were those depicting oiled seabirds. The Gulf of Mexico contains dozens of protected areas and wildlife refuges that host thousands of wildlife species. Some of the most sensitive of these species are birds, and the area most affected by the oil spill contained over 200 bird species.

Birds particularly susceptible to oil
Birds are particularly vulnerable to oil because it affects several physiological and life history traits that are key to survival. First, oiled birds are unable to waterproof their feathers, and so become waterlogged and heavy, and potentially hypothermic. Second, the oil impacts birds' food supply - everything from fish to sand fleas can potentially be coated in the toxic oil, which the birds then ingest. Third, the oil can wash up in sensitive coastal habitats where birds live, fouling areas where birds swim, feed, and nest. The long-term affects of the BP spill are unknown, but researchers have confirmed that the oil both contains carcinogens and that it has broken up into droplets small enough to easily enter the food chain.

6000 dead birds collected - probably 10% of the total
By November, 2010, biologists had collected more than 6,000 birds that had died as a result of the spill. Scientists estimate that only one in ten birds killed by the oil ever wash up on beaches, meaning that the spill may have killed more birds than initially thought. While the long-term consequences of the spill on bird species are not entirely clear, several bird species are thought to be the most vulnerable.

• Brown Pelicans (Pelecanus occidentalis) were featured in many dramatic photographs that emerged from media coverage of the spill. The birds have only recently begun nesting on barrier islands in the Gulf Coast. The species' population has been recovering from the effects of DDT, and were removed from the Endangered Species List in 2009. Brown Pelicans feed and dive in nearshore waters, and can easily ingest oiled fish or become coated in the oil themselves.

• Piping Plover. Photo credit USFWS

  Piping Plovers (Charadrius melodus), a species listed as "threatened" on the Endangered Species List, spends its breeding and nesting season on beaches and barrier islands along the Gulf coast. These tiny birds forage for food in intertidal areas, and, like the pelican, can easily become oiled or ingest oily food items.
• Roseate Spoonbills (Ajaja ajaja), a species known for its bright pink colour, were hunted nearly to extinction in the 19th century for their showy feathers. Currently, this species is "of special concern" in Louisiana and Florida. The oil spill could potentially damage the important mangrove habitat where the birds feed and nest, and individual birds could ingest contaminated fish.

Dozens of organizations in Louisiana and surrounding states will be monitoring the impacts of the oil spill. Hopefully, these beautiful birds will escape lasting harm.

About the Author:
Chantelle Voss is the Owner of YourBirdOasis.com and a birding enthusiast. YourBirdOasis.com will help you transform your garden into your own bird oasis with a variety of beautiful Bird Feeders, Copper Bird Baths, and Bird Houses.