Data from: Metrics matter: the effect of parasite richness, intensity and prevalence on the evolution of host migration

Parasites have long been thought to influence the evolution of migration,
but precisely determining the conditions under which this occurs by
quantifying costs of infection remains a challenge. Here we developed a
model that demonstrates how the metric used to describe infection
(richness/diversity, prevalence, or intensity) shapes the prediction of
whether migration will evolve. The model shows that predictions based on
minimizing richness yield opposite results compared to those based on
minimizing prevalence, with migration only selected for when minimizing
prevalence. Consistent with these findings, empirical studies that measure
parasite diversity typically find that migrants are worse off than
residents, while those measuring prevalence or intensity find the
opposite. Our own empirical analysis of fish parasite data finds that
migrants (of all types) have higher parasite richness than residents, but
with no significant difference in either prevalence or intensity.