To examine whether the Ridley-Tree Act had had a beneficial impact on the livelihood of condors in the wild, blood lead levels of both living and deceased condors were collected. According to the policy itself, the DFG is required to produce “a report on the levels of lead found in California condors [based on data collected during] calendar years 2008, 2009, and 2012” (AB 821, 2007). For the most recent report, published in 2010, the USFWS collected “data on blood lead levels detected in California condors sampled during calendar year 2009” and provided that data to the DFG (California Department of Fish and Game, Wildlife Branch, 2010). After analysis of this data, the DFG found that this data did not conclusively prove a causal relationship between the prohibition of lead ammunition in condor range and the blood lead levels detected in the sampled condors (California Department of Fish and Game, Wildlife Branch, 2010). The Department cites a number of variables that contribute to this uncertainty, in particular that the sources of lead found in condor blood samples “are not specifically known”, the “relationships of sampled condors to hunting activity are not specifically known”, and condors may be feeding in areas not subject to AB 821’s restrictions (California Department of Fish and Game, Wildlife Branch, 2010).