Gastrointestinal Parasites of Wild Birds in Mexico: A Synthetic Review of the Current Knowledge and Approaches for Bird Parasitological Studies

Parasites are part of ecosystems and can regulate populations. The diseases they cause may negatively impact wildlife, sometimes linked to the imbalance created by anthropogenic environmental changes. Mexico harbors more than 10% of the world's avifauna, but there have been few studies on gastrointestinal (GIT) parasites in wild birds of Mexico. The aim of this review was to provide a comprehensive summary of knowledge on GIT parasites of Mexican wild birds and offer suggestions for approaches for future parasitological research on birds in Mexico. We analyzed 85 documents reporting gastrointestinal parasites in wild birds in Mexico. Overall, 73 genera and 96 bird species were reported as hosts for gastrointestinal parasites, representing approximately 8.17% of the bird species richness in Mexico, with the Anseriformes and Pelecaniformes being the most studied hosts. A total of 187 gastrointestinal parasite species have been identified to species level; the least studied phyla are Metamonada and Apicomplexa. Gastrointestinal parasites have been detected in 30 states; the central region of Mexico has been best studied. Game and aquatic species have been the most studied hosts, with few parasitological studies on nonaquatic bird species. Further studies are needed to understand the host-parasite relationships in Mexican landbirds, the diversity of parasites, the ecological factors underlying parasitism, and the impact of parasites in Mexican wild birds under anthropogenic changes.