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Lead shot ingestion and lead poisoning of magpie geese anseranas semipalmata foraging in a Northern Australian hunting reserve

Whitehead, Peter J. and Tschirner, Kurt (1991). Lead shot ingestion and lead poisoning of magpie geese anseranas semipalmata foraging in a Northern Australian hunting reserve. Biological Conservation,58(1):99-118.

Document type: Journal Article
Citation counts: Scopus Citation Count Cited 10 times in Scopus Article | Citations

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Title Lead shot ingestion and lead poisoning of magpie geese anseranas semipalmata foraging in a Northern Australian hunting reserve
Author Whitehead, Peter J.
Tschirner, Kurt
Journal Name Biological Conservation
Publication Date 1991
Volume Number 58
Issue Number 1
ISSN 0006-3207   (check CDU catalogue open catalogue search in new window)
Scopus ID 2-s2.0-0026296121
Start Page 99
End Page 118
Total Pages 20
Place of Publication Netherlands
Publisher Elsevier BV
Field of Research BIOLOGICAL SCIENCES
Abstract Sediments at Howards Springs Hunting Reserve in tropical Northern Territory have accumulated high densities of lead shot (330 000 shot ha-1), most of which is at depths (<20 cm) accessible to foraging magpie geese Anseranas semipalmata. Mean shot density is approximately 9% of density of sedge Eleocharis dulcis tubers, a favoured dry-season food which overlaps with shot in size. Large quantities of grit are available on the fringes of the swamp, but densities of the larger, shot-sized items (> 2 mm) that appear to be preferentially ingested or retained in gizzards are sometimes absent in areas where magpie geese forage. Lead shot are frequently ingested. Over two years 21·4% of a sample of mobile birds ( n = 103 ) had ingested shot in their gizzards. In 1989, 45·2% (n = 65) showed lead concentrations in their livers, indicating lead exposure. However, few birds had accumulated high concentrations of lead in wingbones, suggesting that repeated sublethal exposures are uncommon. We suggest that the combination of high shot ingestion rates and limited recurrence of exposure implies high mortalities from lead toxicosis. This conclusion is supported by the presence of substantial numbers of incapacitated lead-poisoned birds at Howard Springs and other wetlands in the Darwin region. If criteria developed in the USA were applied, these observations would justify immediate prohibition of the use of lead shot at Howard Springs. We discuss steps to inhibit exposure of waterbirds to existing lead shot deposits following a conversion to steel shot.
DOI http://dx.doi.org/10.1016/0006-3207(91)90047-D   (check subscription with CDU E-Gateway service for CDU Staff and Students  check subscription with CDU E-Gateway in new window)
 
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Created: Fri, 29 Aug 2014, 20:27:27 CST by Anthony Hornby