Office of External Affairs
Mountain-Prairie Region


U.S. Fish and Wildlife Service
Mountain-Prairie Region
134 Union Boulevard
Lakewood, Colorado 80228

For Immediate Release                                              

August 19, 2011

Bird mortality in oil and gas production facilities can be prevented

Contact: Pete Ramirez; 307.772.2374;
  Kevin Johnson; 303-236-4518;

Bird in OilWith the approaching onset of the fall migration of birds, the U.S. Fish and Wildlife Service (Service) urges oil operators to inspect their production facilities for hazards to migratory birds. Every year an estimated 500,000 to 1 million birds are killed in oilfield production skim pits, reserve pits, and in oilfield wastewater disposal facilities according to a study published by Pepper Trail, forensic ornithologist with the Service’s Forensics Laboratory in Ashland, Oregon.  The pits attract aquatic migratory birds, such as ducks and grebes, as well as hawks, owls, songbirds, bats, insects, small mammals, and big game. 

Many oil operators install netting to exclude birds and other wildlife from production skim pits and open-topped tanks.  Netting, however, requires intensive maintenance to remain effective at excluding wildlife. Operators should repair holes in the netting and re-stretch the net if it is sagging into the pit fluids.  Pits or ponds with nets sagging into the pit fluids are just as lethal to birds as oil pits with no netting. 

Historically, oil operators used a variety of methods such as flagging, metal reflectors, and flashing strobes to deter migratory birds and other wildlife from oil pits. Studies have shown that flagging, metal reflectors, and flashing strobes are not effective at preventing wildlife mortality in oil pits. Even though flagging is ineffective at preventing bird mortality, many oil operators continue to use it at production skim pits and reserve pits.

Exposed oil is lethal to birds and small wildlife that come into contact with it. Oil in pits or ponds, or oil spilled on the ground, attracts and entraps insects which attract songbirds, bats, and small mammals.  Hawks and owls, in turn, become victims when they are attracted by birds or small mammals entrapped in the oil. 

The sticky nature of oil entraps birds and they die from exposure and exhaustion.  Birds that do manage to escape can die from starvation or the toxic effects of oil ingested during preening.  Birds ingesting sublethal doses of oil can experience impaired reproduction.  Scavengers and predators can also suffer indirect effects by consuming oil-covered bird carcasses. In Wyoming, Service personnel have found waterfowl, songbirds, bats, pronghorn, and deer in oil pits and tanks.  

Bird mortality is not limited to pits and open-topped tanks.  Service biologists have documented songbirds and small mammals entrapped in small puddles of oil resulting from leaking valves, pumps, flowlines, and wells at oil production sites.

Service biologists and special agents have also observed bird mortality in heater treaters (vessels or tanks used to separate oil and formation water) and in small tanks and tubs associated with dehydrator units in natural gas production sites.

Prevention of small drips and spills, properly securing all hoses, valves, and containers, and immediate cleanup of any spilled oil will go a long way to preventing wildlife mortality in oil and gas production facilities.

For more information, please visit the Service web site at:

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