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Title: Linking cases of illegal shootings of the endangered California condor using stable lead isotope analysis

Lead poisoning is preventing the recovery of the critically endangered California condor (Gymnogyps californianus) and lead isotope analyses have demonstrated that ingestion of spent lead ammunition is the principal source of lead poisoning in condors. Over an 8 month period in 2009, three lead-poisoned condors were independently presented with birdshot embedded in their tissues, evidencing they had been shot. No information connecting these illegal shooting events existed and the timing of the shooting(s) was unknown. Using lead concentration and stable lead isotope analyses of feathers, blood, and recovered birdshot, we observed that: i) lead isotope ratios of embedded shot from all three birds were measurably indistinguishable from each other, suggesting a common source; ii) lead exposure histories re-constructed from feather analysis suggested that the shooting(s) occurred within the same timeframe; and iii) two of the three condors were lead poisoned from a lead source isotopically indistinguishable from the embedded birdshot, implicating ingestion of this type of birdshot as the source of poisoning. One of the condors was subsequently lead poisoned the following year from ingestion of a lead buckshot (blood lead 556 µg/dL), illustrating that ingested shot possess a substantially greater lead poisoning risk compared to embedded shot retained inmore » tissue (blood lead ∼20 µg/dL). To our knowledge, this is the first study to use lead isotopes as a tool to retrospectively link wildlife shooting events. - Highlights: • We conducted a case-based analysis of illegal shootings of California condors. • Blood and feather Pb isotopes were used to reconstruct the illegal shooting events. • Embedded birdshot from the three condors had the same Pb isotope ratios. • Feather and blood Pb isotopes indicated that the condors were shot in a common event. • Ingested shot causes substantially greater lead exposure compared to embedded shot.« less
Authors:
 [1] ;  [1] ;  [2] ; ;  [3] ;  [4] ;  [1]
  1. Microbiology and Environmental Toxicology Department, University of California, Santa Cruz, CA 95064 (United States)
  2. National Park Service, Pinnacles National Park, 5000 Highway 146, Paicines, CA 95043 (United States)
  3. Los Angeles Zoo and Botanical Gardens, 5333 Zoo Drive, Los Angeles, CA 90027 (United States)
  4. Ventana Wildlife Society, 19045 Portola Dr. Ste. F-1, Salinas, CA 93908 (United States)
Publication Date:
OSTI Identifier:
22447550
Resource Type:
Journal Article
Resource Relation:
Journal Name: Environmental Research; Journal Volume: 134; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; ANIMAL TISSUES; BIRDS; BLOOD; CALIFORNIA; COMPARATIVE EVALUATIONS; CONCENTRATION RATIO; FASTENING; FEATHERS; HAZARDS; INGESTION; LEAD ISOTOPES; MATERIALS RECOVERY; PLANT TISSUES; POISONING; WILD ANIMALS