Workers for the Louisiana Department of Wildlife and Fisheries and the US Fish and Wildlife Service prepare to net an oiled pelican in Barataria Bay, Louisiana, last Saturday (Image: Petty Officer 2nd Class John Miller/US Coast Guard)

Brown pelicans dripping with oil are quickly becoming the poster children of the ongoing Deepwater Horizon oil spill. As oil slicks continue to lap at the pelicans’ breeding grounds in coastal Louisiana, armies of wildlife rehabilitators are frantically trying to catch and scrub the contaminated birds clean. What does it all mean for the long-term survival of the species – just months after they were taken off the US endangered species list?

How endangered is the brown pelican?

The species as a whole isn’t about to go extinct as a result of the oil spill: as 400,000 out of a total global population of 650,000 live in Peru. Roughly 60 per cent of the subspecies Pelecanus occidentalis carolinensis breed along the Gulf coast, where many nest on the barrier islands off Louisiana that have already been exposed to oil.


The slicks threaten the birds and their fragile wetland habitat only a few months after brown pelicans were removed from the US federal endangered and threatened species list in November last year. The birds had been on the list since 1970 after the pesticide DDT poisoned and nearly wiped out pelicans across the country. At the time Louisiana, where the pelican is the official state bird, lost its entire population. After years of resettling individual birds from Atlantic coast populations, Louisiana was able to boast the largest brown pelican population of any Gulf state, with 16,000 nesting pairs in 2004.

Will the spill cause brown pelican populations to crash and require them to be relisted?

It’s still too early to say, simply because no one knows how much oil will have been spilt by the time the leak is finally plugged. The US Endangered Species Act requires federal biologists to keep close tabs on pelican populations for the first five years after delisting. If populations drop significantly in the Gulf, brown pelicans could be relisted, even if populations along the Pacific and Atlantic coasts remain stable.

“It isn’t rocket science,” says Roger Helm, chief of environmental quality for the US Fish and Wildlife Service. “If you have a small population and you whack it hard, there is going to be a significant impact.”

How are oiled birds rescued from the spill and cleaned?

Only a small fraction of oiled birds are ever found – many die at sea or on remote shores. Those that are found and can be approached are covered with vegetable oil to loosen up the crude oil before being cleaned with dishwashing liquid.

Wildlife rehabilitators continually make subtle tweaks to this process to try to increase survival rates, such as minimising stress with the help of improved enclosures and longer rest periods.

Birds are also given water and electrolytes while they are cleaned to keep them hydrated. Those thought to have swallowed oil may be given coal or indigestion medication to reduce the amount of oil absorbed by their digestive system.

Do the cleaned birds stand a chance of survival or should they be killed humanely?

The International Bird Research Rescue Center, one of two organisations heading up the treatment of oiled birds in the Gulf, claims that 50 to 80 per cent of the birds treated survive at least to the point of where they can be released back into the wild. This is a major improvement from just 4 per cent during the organisation’s first oil spill response in 1971.

The survival rate following release is more difficult to determine and is subject to controversy. The biologist Silvia Gaus recently called for oiled birds to be killed humanely, claiming 99 per cent of released animals die within days or a few weeks due to stress or kidney and liver damage from ingesting oil. But several reports, including a pair of recent small-scale radio-tracking studies, suggest cleaned birds have a good chance of long-term survival even compared with birds that were never oiled. Survival prospects also vary depending on the species and spill conditions.

What will happen to the pelicans once they are released?

The US Fish and Wildlife Service is releasing rehabilitated pelicans on Florida’s Atlantic coast. Federal biologists hope the birds will remain in their new locations as reintroduced birds from the Atlantic coast formed new colonies in Louisiana in recent decades. While this may work for young birds, breeding adults are likely to make their way back to their nest sites and, depending on how quickly they return, they could be exposed to oil once again.

To ensure the long-term survival of brown pelicans along the Gulf coast, significant work may be needed in coming years to restore the wetlands and fisheries that the birds depend on for breeding and feeding. At the time of posting 442 oiled birds had been captured and roughly a dozen brown pelicans had been released while a large number remained in holding pens.

What are the costs of the rehabilitation programme, and who foots the bill?

Figures from the clean-up of the 1989 Exxon Valdez oil spill put the cost at $15,000 per marine bird for a total of 627 birds released. This covers building rehabilitation centres, staff and helicopters and private boats. The cost of caring for wildlife after recent oil spills has amounted to roughly 1 per cent of the total clean-up costs.