Forest Type and Body Size Drive Blood Parasite Infections in Afrotropical Ant-Following Birds

Forest fragmentation due to deforestation is a major threat to biodiversity in the Afrotropics, particularly affecting specialized avian guilds such as ant-following birds. While their population declines have been documented, the influence of habitat disturbance on their prevalence remains poorly understood. This study investigates the prevalence of five blood and tissue parasites (Plasmodium, Haemoproteus, Leucocytozoon, Trypanosome, and Microfilariae) in ant-following birds across a degraded tropical rainforest in South Western Cameroon, and explores the relationship between infection status, ant-following behavior and bird weight. Blood samples from 520 birds were analyzed using microscopy and PCR, which was run for only microscopy positive samples. Plasmodium was the most commonly encountered parasite genus with a prevalence of 76.5% in Chamaetylas poliocephala, followed by Leucocytozoon with 45.5% in Neocossyphus poensis, Trypanosoma with 40% in Phyllastresphus xavieri, Haemoproteus with 36.4% in Neocossyphus poensis and microfilariae with 27.3% in Alethe castanea. Trypanosoma prevalence was significantly higher in fragmented forests (p = 0.0235) in ant-followers, while the other parasites showed no significant difference across forest types. Ant-following birds consistently had higher parasite prevalence than none ant-followers. The ant-following nature of an avian host influences the prevalence of parasites it harbors. Logistic regression confirmed that higher bird weight significantly increased the odds of infection with several parasites, especially Haemoproteus (p = 0.0009) and Leucocytozoon (p = 0.0022) and Microfilariae (p = 0.0036). These findings underscore the subtle but important effects of habitat disturbance and host physiology on avian parasite ecology.