Haemosporidians in migratory blackcaps (Sylvia atricapilla), a comparison between autumn and spring periods of passage

Abstract

The spatio-temporal host-parasite relationships have a high interest to understand the coevolutionary processes between parasites and their hosts. Our main aim here was to analyse whether the prevalence and intensity of infection by haemoparasites in migrating blackcaps (Sylvia atricapilla), at a stopover site in N Iberia, varied throughout and between migration periods. Moreover, we studied whether the parasitaemia had any effect on fuel load. Blood smears were studied from 132 individuals. Only Haemoproteus spp. and Plasmodium spp. were detected. Trypanosoma spp., microfilaria or Leucocytozoon spp. were absent. The prevalence was 35% and it did not differ throughout and between periods or between age classes, but between the sexes. Prevalence was higher among males (45.5% versus 22.7%), suggesting that males were more prone to be infected, which could be due to sex-associated immunologic variations. The mean intensity of infection was low (2.8 parasites/2000 erythrocytes). We did not find any effect of parasitaemia on fuel load.