Q1: Fitness effects of stressors on infected and
uninfected hosts
After confirming that pathogen infections in surveyed literature reduce
host fitness (Fig. S2; Fig. S3; Table S1), we asked if effects of
stressors on fitness are modulated by infection status (Q1). The lowest
AICc model for Q1 included stressor type, response trait, and their
interaction as moderators (Table S2). Our data, therefore, does not
support differential effects of environmental stressors between infected
and uninfected hosts (Fig. S4). The interaction between stressor type
and response trait resulted primarily from a relatively strong negative
effect of resource limitation on fecundity (Table S3; Fig. 2) and a
relatively strong negative effect of endogenous environmental stressors
on survivorship (Table S3; Fig. 2). Pollution also negatively affected
survivorship (Table S3; Fig. 2), but this effect was contingent on
results of low precision studies (see Evidence of publication bias).
These contrasting effects of the three stressor types were qualitatively
similar if the RVE was used instead of modeling sampling-error
covariances (Fig. S5). Differences in effect sizes both within
(I2 = 40.42%) and between (I2 =
53.41%) experiments contributed to relatively high total heterogeneity
(I2 = 93.83%).