Impacts of agricultural habitat on gastrointestinal parasites in wintering Asian Great Bustards ( Otis tarda dybowskii )

Parasite infection can impair avian nutrition and health and may contribute to population declines. The Asian Great Bustard ( Otis tarda dybowskii ) is a farmland-dependent wintering bird, yet its gastrointestinal parasite infection remains poorly studied, and the effects of agricultural habitat type on parasite community structure and infection intensity are unclear. We compared gastrointestinal parasite infection among wintering Great Bustards using fecal samples collected from four agricultural habitats. Eggs per gram of feces (EPG) were quantified using the McMaster counting method. Parasite shedding was highly aggregated (k < 1), indicating that parasite egg shedding was concentrated in a small number of samples with high EPG values. Total, nematode and cestode EPG values were significantly higher in the wheat + corn habitat than in the other habitats, whereas the wheat + alfalfa habitat showed the lowest overall EPG values. Nematode and cestode EPG values were significantly positively correlated (ρ = 0.62, p < 0.001), indicating positive covariation between nematode and cestode egg shedding. These findings provide baseline evidence for habitat restoration and low-intervention parasite risk management in farmland-dependent wintering birds.