Plasmodium parasites were sought in 30 skylarks (Alauda arvensis) captured in the Département des Landes (France) during the post-mating migration. Parasite prevalence was low (6/30) while intra-specific diversity was high (14 species). Five species were morphologically indistinguishable from those found in the magpie (Pica pica) from the Paris region: Plasmodium dorsti, P. bioccai, P. ghadiriani, P. dherteae, and P. relictum quentini n. subsp. Two species had been described in other birds: P. rouxi and P. hexamerium. The species Plasmodium alaudae (Celli & Sanfelice, 1891) is redefined in this article. Finally, five new species are described and named: P. reniai n. sp., P. coluzzii n. sp., P. caloti n. sp., P. ginsburgi n. sp. and P. jeanriouxi n. sp., and one, Plasmodium sp. is described but not named. The pattern of infection in the skylark, a migratory gregarious bird, is compared to that of the magpie, a solitary sedentary bird.
Apicomplexa, Plasmodium, Alauda arvensis, migratory gregarious bird, Pica pica, sedentary solitary bird, new species.