Figure 1. Variation in preference for fat-enriched food (as opposed to
preference for anthocyanin-enriched food) between blackcaps with
different levels of multiple status of infection by haemosporidian
parasites. Preference estimates with 95% confidence intervals represent
the probability (expressed as a percentage) that feeding-oriented
behaviours are directed to fat-enriched food, controlling for residual
body mass and year. The horizontal dashed line set at 50% indicates the
absence of preference for either food choice. Dots are observations of
single feeding-oriented behaviours, which therefore take values of 0%
if directed to anthocyanin-enriched food and 100% if directed to
fat-enriched food, jittered to reduce overlapping. The identity of
individuals expressing these behaviours has been controlled as a random
factor in the model.
Table 1. GLMMs that analyze variation in food preference as a function
of ecological condition (residual mass and parasite infection),
controlling for the fixed effect of year, and including individual
differences as a random factor. Significant results are highlighted in
bold. Different models (in columns) with parasite infection quantified
as the multiple infection status or the intensity of the infection were
tested.