Body of Evidence: How the White Pelican Spreads Oil
The Brown Pelican became the symbol of the BP oil spill, but the White Pelican is offering clues to its lasting stain on bird populations.
In the wake of the Deepwater Horizon oil spill in 2010, disturbing photographs of Brown Pelicans coated in oily sludge played nonstop on TV news and ricocheted around the Internet. Now American White Pelicans, which migrate inland (unlike their brown relatives), seem to be revealing the far-reaching consequences of the disaster more than 1,400 miles from the Gulf, at Marsh Lake on the Minnesota River, where 12,000 to 14,000 pairs nest in May and June.
Biologists from North Dakota State University and the Minnesota Department of Natural Resources have been collecting samples in the form of eggs and the odd-looking bill knobs, or nuptial tubercles, that pelicans shed after mating season. The scientists are analyzing the samples, looking for evidence of chemicals from both the oil and the dispersants used to clean up the spill.
The latest tests show markers of contamination, particularly in the eggs. 鈥淲e have documented evidence from the oil as well as the dispersant,鈥 confirmed Lori Naumann of the Minnesota DNR.
Saying definitively that the lingering chemicals came from the BP spill is challenging, said population biologist Mark Clark, the lead North Dakota State researcher, but the findings are consistent with that hypothesis. Still, any dramatic consequences for populations may take years to appear.
The results of the study are important for many reasons. For one thing, they could affect the distribution of money from fines and other lawsuit-related charges if the courts determine the birds have been harmed. Even Canada, which has large breeding populations of White Pelicans in its prairie provinces, may have a claim on damages.
The North Dakota State team is wrapping up its sample collections, with plans to submit the study results to a journal for peer review. Meanwhile, another biologist, Mark Martell of 爆料公社 Minnesota, is leading an effort to track the White Pelicans鈥 movements during migration. His team is fitting pelicans with GPS units that send data via cell towers, unlike older tracking devices that rely upon satellites. 鈥淚t鈥檚 like putting an iPhone on the backs of birds,鈥 he said鈥攁nd it means the data are more precise. Besides connecting the dots between the wintering and breeding grounds, the study is revealing that White Pelicans make plenty of pit stops during migration. That information can help identify the places along the birds鈥 travel routes that should be considered conservation priorities.
The tracking project is also confirming some of what biologists already know. For instance, White Pelicans, one of North America鈥檚 largest birds鈥攖hey weigh up to 20 pounds and have a 9-foot wingspan鈥攕pend much of their time near shore, skimming fish from the water鈥檚 surface. (Brown Pelicans, by comparison, feed below the surface.) They also appear to share territories more willingly than some other coastal migrants, such as loons.
The researchers aim to fit 15 more pelicans with transmitters this summer.
Book author Mark Neuzil teaches journalism at the University of St. Thomas in St. Paul, Minnesota.