Non-anthropogenic diet-based oiling of predatory birds

Oiling of wildlife can have important consequences to individual animals and populations (Kingston 2002). Individual birds that are heavily oiled lose their ability to fly and may become ill or die from hypothermia, starvation, exhaustion, or drowning (Clark 1984, Rocke 1999). For example, large-scale oiling from the Exxon Valdez spill caused local declines in populations of many avian taxa (Irons et al. 2000). Although most oiling reports involve marine wildlife exposed to oil leaked from vessels or oil rigs, oiling also can occur in terrestrial environments, for example, via birds drinking water in puddles on asphalt roadways (Clark and Gorney 1987) or landing in oil field wastewater disposal facilities (Trail 2006, Ramírez 2010).