Data from: Adaptive immunity modulation linked to migratory behaviour in two partially migratory hoopoe populations (Upupa epops)

Ecophysiology has enhanced our understanding of avian migration, yet many
aspects of how these processes interrelate are still unclear. Partially
migratory populations provide an ideal framework for its study in the
wild, since resident and migratory individuals coexist temporarily in the
same area, and face similar selection pressures. We focused on two Iberian
populations of Eurasian hoopoe (Upupa epops), a trans-Saharan
long-distance migrant, to explore the links between the immune system and
migratory behaviour. We determined the migratory status of individual
hoopoes using stable isotope analysis of deuterium (2H) and measured a
number of immunological parameters, including estimates of innate and
adaptive immunity, as well as body condition, and muscle and fat stores.
Our results indicate that resident hoopoes had higher IgY levels and
higher muscle and fat stores compared to migrants during the breeding
season. Moreover, we found seasonal variation in leukocyte profiles of
resident birds, with higher H/L ratios in winter than during the breeding
season. We observed significantly higher H/L ratios and complement
activity in resident males than in resident females, but not within
migratory birds. Overall, we show differences in immune response linked to
migratory behaviour in partial migratory populations. This study
contributes to unraveling the associations between physiological status
and migratory behaviour and ultimately helps to understand how different
migratory strategies are maintained in partially migratory populations.