Figure 2. Hypothetical changes in blood lead concentration over time for California condors moving between zones with high and low daily risk of ingesting lead.
The schematic diagram shows average hypothetical changes in blood lead concentration (µg dL−1) for condors moving between zones with high and low daily risk of ingesting lead. Curves show the time course of components of blood lead derived from each day's intake. Birds remaining in the low risk zone (A) throughout would be expected to show a decline in blood lead over the time between a pair of measurements (open circles). Birds visiting the high risk zone early in the interval between measurements (B) would be expected to show an increase in blood lead concentration. Birds visiting the high risk zone for the same number of days, but later in the interval (C), would be expected to show the highest increase in blood lead concentration.