Data collection
Once a week, the entire 40-ha forest patch was thoroughly surveyed
searching for active nests (of all bird species). This was consistently
done during the 8 breeding seasons. When eggs were identified, the nest
was marked and systematically followed weekly until all nestlings left
or died. Every week, the nestlings of each brood (of all bird species)
were examined in search of external parasites following procedures
described in detailed by Manzoli et al. (2013). Larvae of ‘P.
torquans c. A.’ detected were counted and their stage recorded as L1
(<4mm), L2 (4 – 7mm) and L3 (>7mm). For this
study, we only used the data from the period of the breeding season in
which the three species of interest are expected to be breeding (weeks 5
to 25 from the September [spring] equinox; Figure 1).
Climatic data were obtained from the closest meteorological station. The
climatic variables used in the analysis were weekly precipitation (mm)
and weekly temperature (minimum, maximum and mean), as they were
previously found to be significantly associated with ‘P. torquansc. A.’ occurrence and abundance (Antoniazzi et al. 2011; Manzoli et al.
2013).