Lead Toxicity in Mute Swans

Lead Levels In Mute Swans In
Cork
By John O'HalloranandP.F.Duggan
Introduction
Lead poisoning, apparently resulting mainly from the ingestion of
spent lead gun shot pellets and disgarded anglers' weights, has been
shown to be an increasing hazard to waterfowl throughout the
Holarctic. (Rosen and Bankwoski 1960, Evans et al 1973, Birkhead
1983). In the United States of America, where the condition was first
recognised in 1874, the situation is now considered to be widespread
(see Philips and Lincoln 19 30). However, though researched in a total
of 14 other countries, information on lead poisoning in waterfowl has
never been addressed in Ireland. In an effort to remedy this situation
this present research* was carried out (and is continuing).
Mute Swans Cygnus olor were selected for study in Co. Cork at a
fishing area with a resident swan population of up to 200 birds and,
for comparison, at areas where there was little coarse fishing. The
Lough, Cork City (Plate 70) is fished throughout the year, often with
Plate 70. The Lough, Cork
Photo: Richard T. Miller
*This work formed part of a thesis for the Honours Degree in Zoology of the
Na ti on al University oflreland, at University College, Cork. (0 'Halloran 19 84).
Irish Birds 2:501-514, 1984.
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