Oil and birds don't mix
The Gulf is one of the worst places an oil spill could hit from a bird-centric point of view. Learn why from Dave Mehlman, The Nature Conservancy's director of migratory bird conservation.
Thu, May 13, 2010 at 10:33 AM
The oil spill in the Gulf of Mexico continues to occupy our top environmental headlines. I expect that, unfortunately, soon we will see some of the more iconic images that tend to come out of these crises: that of oil-soaked birds (most of which will be cleaned and, hopefully, released).
Tthough no such oil spill can occur in a “good place,” the Gulf is a particularly bad spot for a major oil spill from a bird-centric point of view. There are two primary reasons why the Gulf Coast is important for bird conservation:
It is a zone of immense importance for the migration of North America’s birds, with an enormous percentage of individuals and species migrating through or across the region twice per year (see our feature on the Gulf Coast as a top 10 birding spot); and
The wetlands and islands of the Gulf harbor large populations of the nation’s breeding and wintering waterbirds, shorebirds and waterfowl.
In the first case, the northern coast of the Gulf — from the Florida panhandle west to approximately Galveston, Texas — is an extremely important migratory stopover point during spring and fall migration.
In spring, the barrier islands and coastal habitats are the first habitats that migrating birds encounter after leaving the night before on their long overwater flights north. Under certain weather conditions during the peak of migration, this region is famed for its migratory “fallouts,” when hundreds or thousands of birds can be literally underfoot.
Some of the continent’s legendary migration hotspots, such as Dauphin Island and Fort Morgan, Ala.; the islands of the Gulf Islands National Seashore in Mississippi and Florida; Grand Isle, La.; and High Island, Texas, are in this zone and are right in the current or predicted path of the oil slick.
The timing of the spill also could not have been worse, since it occurred just after the typical peak of the spring migration in the first two weeks of April.
Having said this, my personal opinion is that the majority of these migratory birds (warblers, vireos, thrushes, tanagers, buntings, grosbeaks, etc.) will be slightly affected, if at all, by the spill. Here's why:
They migrate over water, so would not likely come into direct contact with the oil.
They predominantly use shrubs, trees, vines, and other terrestrial vegetation, which would be secondarily affected by the spill.
Finally, we are now well past the peak of migration, so the total number of individual birds potentially exposed is diminishing daily. That’s the good news.
I think, however, that the prognosis is not as good for the breeding and wintering waterbirds, shorebirds and waterfowl, although at least most of the wintering individuals had left by the time the spill occurred:
Most of these birds nest on low islands with little vegetation (a great example is the Chandeleur Islands, Louisiana) and so will be unable to avoid becoming fouled with oil themselves or their eggs or chicks.
Most of these species also feed on fish in the Gulf waters and so will become tarred with oil the first time they feed. If oil gets into coastal marshes, critically important habitat for species such as the seaside sparrow will also be damaged or destroyed.
The outlook for these birds is not good, and I think the effects of this spill will be felt for quite a while unless it is fixed very soon.
The Gulf of Mexico coast is one of our most important “bird regions” in the country. The conservancy has dedicated numerous resources over the years to protect this region and its birds, including work done through the Migratory Bird Program’s Gulf Wings project and that done by our Florida, Alabama, Mississippi, Louisiana and Texas programs. However, I am saddened that this important work had to be highlighted in such a spectacular and negative way.
— Text by Dave Mehlman, Cool Green Science Blog