Because they are high level predators, peregrine falcons play an important role in regulating populations of their prey, particularly pigeons and doves (Columbidae), ptarmigan (Lagopus), and ducks (Anatidae)

Peregrine falcons harbor, and are susceptible to, a number of parasites and diseases, including avian pox (Poxvirus avium), Newcastle disease, herpes virus, mycotic infections, strigeid trematodes (Strigeidae), nematodes (Serratospiculum amaculata), malaria (Plasmodium relictum), tapeworms, and bacterial infections. Ectoparasites include chewing lice (Phthiraptera, including Colpocephalum zerafae, Degeeriella rufa, Laemobothrion tinnunculus, and Nosopon lucidum), fleas (Ceratophyllus garei), and flies (Icosta nigra and Ornithoctona erythrocephala).

Commensal/Parasitic Species:

• Ornithoctona erythrocephala
• Icosta nigra
• Ceratophyllus garei
• Nosopon lucidum
• Laemobothrion tinnunculus
• Degeeriella rufa
• Colpocephalum zerafae
• Plasmodium relictum
• Serratospiculum amaculata
• Strigeidae