Survey and host fitness effects of red-cockaded woodpecker blood parasites and nest cavity arthropods.

Blood parasites and nest cavity arthropods associated with the red-cockaded woodpecker (Picoides borealis) were surveyed and the impact of blood-feeding arthropods on woodpecker fitness traits was assessed. Five woodpeckers (8%) were infected with unidentified microfilariae, and 1 woodpecker (2%) was infected with 2 species of haemoproteid (Haemoproteus velans and Haemoproteus borgesi). This is the first record of haemoproteids in this species and the first observation of H. borgesi in North America. We collected representatives of at least 6 families of mites and 12 families of primarily commensal insects from woodpecker cavities. Only a few specimens of blood-feeding insects were recovered. The mite Androlaelaps casalis was the most common hematophagous arthropod (prevalence = 76%, mean density = 51+/-7 mites/cavity). The number of A. casalis mites increased with cavity age but there was no association between the number of mites and the number of woodpecker eggs laid or the number of hatchlings or fledglings. In conclusion, the prevalence of blood parasites in the red-cockaded woodpecker is low, woodpecker cavities are not heavily infested with blood-feeding insects, and there is no evidence that A. casalis mites affect woodpecker fitness.