Data from: Age-related parasite load and longevity patterns in the sedge warbler Acrocephalus schoenobaenus

We report the results from a nine-year study on parasite infection in
males of a small migrant passerine, the sedge warbler Acrocephalus
schoenobaenus. Every year, for each male caught during territory
establishment we estimated infection intensity of two lineages of
Haemoproteus belopolskyi (SW1 and SW3), using molecular methods. We found
a significant relationship between infection intensity and males’
longevity in both studied lineages. There was severe mortality of
second-year sedge warblers after their first breeding season, with lower
parasite load in survivors. The lower infection intensity in older age
classes was related to between-individual change in both lineages, but was
also a result of differences in infection intensity during the lifetime of
individual males in the SW3. The relation between parasite load and
longevity suggests that parasite load may be an age-dependent factor
influencing individual survival.