METAL RESIDUES IN TISSUES AND FOOD OF A JUVENILE PURPLE HERON, ARDEA PURPUREA (ARDEIDAE)

Summary

Van Eeden, P.H., Schwnbee, H.J. & Du Preu. H.H. 1996. Metal residues in tissues and food of a juvenile Purple Heron, Ardea purpurea (Ardeidae). Ostrich 67:67-71.

Tissues as well as the stomach contents of an apparently sick, male, juvenile Purple Heron Ardea purpurea (477 g body weight) were analysed for 13 metals. The bird was caught in the industrial area of Germiston on the East Rand of Johannesburg. The gross pathological abnormalities observed in this heron were similar to those found in birds that died from exposure to acute concentrations of lead-containing compounds. The aluminium and lead residues were considered to be indicative of acute exposure whilst the concentration of cadmium was indicative of chronic exposure. Silver was not detected in all the samples analysed. Concentrations of cobalt, manganese and strontium were generally smaller than 100 pg/g dry mass whilst chromium, copper, nickel, zinc and antimony were smaller than 500 pg/g. Iron occurred in the highest concentrations in all tissues. Comparisons with other Ardeidae indicated that this juvenile Purple Heron generally had higher metal residues than either fledgling, juveniles or adults from unpolluted and polluted areas. Therefore, the death of this Purple Heron might be attributed to the synergistic action of a combination of metals.