Ž . Comparative Biochemistry and Physiology Part C 129 2001 243264 Persistent organochlorine pesticides detected in blood and tissue samples of vultures from different localities in South Africa Erika van Wyk a , Henk Bouwman b , Herman van der Bank a,  , Gerhard H. Verdoorn c , Dieter Hofmann a a Sanlam Research Unit for En ironmental Conser  ation, Department of Zoology, Rand Afrikaans Uni  ersity, P.O. Box 524, Auckland Park, 2006, South Africa b Unit for Pesticide Impact, Plant Protection Research Institute, Agricultural Research Council, Pri  ate Bag X134, Pretoria, 0001, South Africa c Endangered Wildlife Trust Raptor Conser  ation Fund, P.O. Box 72115, Park iew, 2122, South Africa Received 10 July 1999; received in revised form 19 April 2001; accepted 23 April 2001 Abstract Gaschromatography was used to establish the presence of quantifiable residues of 14 persistent chlorinated hydrocarbon pollutants in whole blood, clotted blood, heart, kidney, liver and muscle samples obtained from individual Ž . Ž . Ž . African whitebacked Pseudogyps africanus , Cape griffon Gyps coprotheres and Lappetfaced Torgos tracheliotos vultures from different localities in South Africa. The levels of pesticides measured in whole blood samples of live specimens were compared between nestlings from two natural breeding colonies, adults from a wildlife area and birds Ž . held in captivity. Statistically significant P 0.05 differences between populations were detected in geometric means Ž . Ž . calculated for -BHC lindane ,  cis -chlordane and -endosulfan. Five of the organochlorine contaminants displayed significant variations between concentrations detected in the clotted blood, organs and muscles excised from vulture carcasses. This includes residues of -BHC, -chlordane, dieldrin, -endosulfan and heptachlor epoxide. Values of the respective biocides measured in vulture samples were generally low in comparison to results documented for a number of avian species. Although no threat is posed by any of the organochloride pesticides, continual monitoring of especially breeding colonies is recommended. Furthermore, the suitability of African whitebacked vulture nestlings as basic bioindicators is highly advocated.  2001 Elsevier Science Inc. All rights reserved. Keywords: African whitebacked vulture; Bioindicators; Blood concentrations; Chlorinated hydrocarbons; Ecotoxicology; Organochlo- rine pesticides; Tissue samples; Vulture species  Corresponding author. Tel.: 27-11-489-2450; fax: 27-11-489-2286. Ž . E-mail address: fhvdb@na.rau.ac.za H. van der Bank . 1532-045601$ - see front matter  2001 Elsevier Science Inc. All rights reserved. Ž . PII: S 1 5 3 2 - 0 4 5 6 01 00201-0