Fig 1.
Map of sampling locations in northern Malawi.
Vwaza Marsh Wildlife Reserve, red; Nyika National Park, orange. Image credit: USGS National Map Viewer.
Table 1.
Sampling localities and habitat types in Malawi.
Table 2.
Fixed effects in the set of 15 models and the relative support of data for these models (ΔAICC values) from AIC-based multi-model comparisons. We used these comparisons to identify life history traits associated with rates of haemosporidian parasitism of avian hosts. An “X” indicates that a given trait (column) was used as a fixed effect, categorical variable in a given model (row). For each parasite genus the model with the ΔAICC value of zero is the best-supported model.
Table 3.
Tests of statistical significance of host phylogenetic constraints on probability of parasitism. Phylogenetic effects were examined in our analyses by including nested random effects of host family, genus (within family), and species (within genus) on the probabilities of parasitism with each of the three genera of parasites. Statistical tests were likelihood ratio tests each with a single degree of freedom.
Table 4.
AIC-based support for fixed effects. Values are sums of model weight values for all models in the set (Table 2).
Table 5.
Model-averaged regression coefficients, standard errors, and 95% confidence limits used to estimate effects of predictors and precision of effects. Note that for each predictor, the regression coefficients are interpreted as describing deviations in parasitism rates from a reference category whose effect is subsumed into the intercept term of the statistical model. Thus, although we can compare parasitism rates of understory nesting species with ground nesting species (the reference category for nest location) using the model-averaged regression coefficients, we cannot use these coefficients to directly compare parasitism rates of understory and canopy nesters.
Fig 2.
Predicted (least-squares mean) probabilities of parasitism and their 95% confidence intervals.
Expected rates of parasitism illustrated according to (a—c) host nest type, (d—f) host nest location, (g—h) host flocking behavior, and (i) habitat. For all panels, Plasmodium is represented by a black diamond and the letter “P”, Haemoproteus is represented by a black square and the letter “H”, and Leucocytozoon is represented by a black circle and the letter “L”. Number of individuals and species comprising each trait are listed below their respective traits (number of individuals above, number of species below in parentheses). Note that the parasitism rate of zero has been plotted for the aquatic habitat without confidence intervals; because the four individual aquatic-habitat birds sampled lack Leucocytozoon infections and therefore could not be used in the statistical analysis (as noted in the Methods section) Thus no measure of statistical confidence is associated with this aquatic habitat plotted point.
Table 6.
Rates of parasitism by higher level avian taxa (Order and Family).
Table 7.
Haemosporidian abundance and diversity.
Table 8.
The distribution of resolved coinfections among three genera of parasites.
Table 9.
Comparative overview of some studies in avian haemosporidian prevalence and diversity.