Fig. 1. The correlation between the intensity of parasitemia as estimated from smear counts and qPCR. Filled circles show data for GRW2 and open circles for GRW4. The dotted line is the expected 1:1 ratio. Because smear counts based on 10,000 erythrocytes cannot detect intensities of parasitemia <0.01%, zero-counts were given the value of 0.001 in the statistical analyzes.

Fig. 2. Dynamics of parasitemia of Plasmodium ashfordi (lineage GRW2, red) and P. relictum (combined data for lineages GRW4/SGS1/GRW11, blue) in six juvenile great reed warblers experimentally inoculated with infected blood from the adult donor #968 on 21 September (a, d and e) and donor #043 on 3 December (b, c and f). The birds on the left panel (a, b, c) survived until the monitoring of parasitemia was terminated (shaded grey area) whereas the birds on the right panel died 35–70 days post infection. The intensity of parasitemia (¹⁰log scale) was measured with qPCR (see Section 2). Three digit numbers indicate individuals as listed in Table 2. The birds #214 and #227 showed non-zero values on day 0 as a result of uncontrolled transmission of SGS1 and GRW11. (For interpretation of the references in colour in this figure legend, the reader is referred to the web version of this article.)

Fig. 3. Dynamics of parasitemia of Plasmodium relictum (combined data for the lineages GRW4/SGS1/GRW11) in juvenile great reed warblers experimentally inoculated with infected blood from (a) donor #042 on 21 September and (b) donor #039 on 3 December. Three digit numbers indicate individuals as listed in Table 2. Two birds (#424 and #429) died before the monitoring of parasitemia was terminated (shaded area).

Fig. 4. The correlation between the intensity of parasitemia of Plasmodium ashfordi (lineage GRW2) and P. relictum (combined lineages for GRW4/SGS1) in two juveniles (a: #228; b: #227) and one adult great reed warbler (c: #968).

Fig. 5. The relationship between mean intensity of parasitemia of Plasmodium ashfordi (lineage GRW2) and P. relictum (GRW4 grey circles, SGS1 black circles) in great reed warblers with mixed infections (r = 0.63, P = 0.16). Below the stippled line is the intensity of parasitemia higher in P. ashfordi than in P. relictum.

Prevalence and identity of blood parasites in 52 adult great reed warblers captured at the Kalimok station in Bulgaria during June 2005

Details about the two infection experiments with Plasmodium ashfordi (lineage GRW2) and P. relictum (GRW4)

Mean and maximum intensity of parasitemia of three Plasmodium spp. lineages in adult donor and experimental juvenile great reed warblers

For experimental juveniles, the number of days from inoculation to when parasitemia first reached the intensity of 0.04% are given

Repeatability of the intensity of parasitemia in great reed warblers infected with lineages of Plasmodium ashfordi (GRW2) and P. relictum (GRW4, SGS1)