Different susceptibilities to white phosphorus poisoning among five species of ducks

Abstract

Abstract-Three species of ducks, mallard (Anas platyrhynchos), northern pintail (Anas acuta), and green-winged teal (Anas crecca), that frequent an estuarine salt marsh in Alaska during migration die in large numbers from ingesting particles of white phosphorus. Two other common species, northern shoveler (Anas clypeata) and American wigeon (Anas americana), are rarely found dead. Selectivity indices show that this difference in mortality is not due to different numbers of each species being present. We investigated three hypotheses for the difference in susceptibility to this poison. First, we found that wigeons had more total grit in their gizzards than the susceptible species and shovelers had a high proportion of particles Ͼ1 mm compared to other species. Thus, ingestion of particles of white phosphorus as grit cannot explain the differences in susceptibility. Second, feeding behavior could not completely account for the lack of susceptibility in shovelers. Shovelers often forage with their neck or more in the water and often have their bills in the sediments. Wigeon, however, frequently forage with just their bill in the water and rarely penetrate the sediments. This feeding behavior, coupled with a diet consisting mainly of plants, may limit exposure of wigeon. Third, shovelers have wide upper bills, with lamellae consisting of long thin filaments extending from the upper bill inward toward the lower bill. These lamellae may allow white phosphorus particles to be flushed out during feeding. Thus, if physiological tolerance to white phosphorus is similar among these species, the difference in susceptibility appears to be due to differences in feeding behavior and bill morphology.

Remediation methods for white phosphorus contamination in a coastal salt marsh

“…Mortality, however, was confined mostly to dabbling ducks and swans. Extensive ground surveys indicated that very few surface feeding birds or shorebirds were affected (Steele et al 1997). A series of investigations culminated in the discovery in 1990 of the cause of the mortality, namely the ingestion of white phosphorus particles (Racine et al 1992).…”

“…The particles thus became available to dabbling waterfowl, which, mistaking them for similarly sized and shaped food items (Fig. 2), sieved them from the fine sediments of the ERF (Steele et al 1997). Investigations into the chemistry of white phosphorus (Racine et al 1993b;M.E.…”