"It takes many types of parasite eggs a while to ripen," said Dr. Emily Beeler, an animal disease surveillance veterinarian for the Los Angeles County Department of Public Health.
It has few natural predators, but may harbour several types of parasite; the plumage is home to chewing lice and feather mites, while the large nests maintain a diverse range of mesostigmatic mites.
However, the differences in parasite load could also reflect genetically-based differences in immunocompetence or host behaviour, given that prevalence of two types of parasite with different host specificity and life cycle shows the same pattern across the hybrid zone.
The two types of parasite are not directly linked: Ixodes ricinus is not known to be a vector of any haemogregarine parasite and is well studied in nature because it is a vector of Lyme disease, menigoencephalitis and other diseases affecting humans.
So, are all types of parasite adhesion equally damaging?
During microscopic examination of stool samples fourteen types of parasite's genera were identified and 55.0% (208/378) of the study subjects were positive for at least one intestinal parasite.
