AVIAN HAEMOSPORIDIANS IN GREATER SCAUP (AYTHYA MARILA) AND LESSER SCAUP (AYTHYA AFFINIS) FROM WISCONSIN

Area of Science:

• Parasitology
• Ornithology
• Molecular Ecology

Background:

• Avian haemosporidians are diverse protozoan parasites impacting many bird species.
• Waterfowl, particularly diving ducks like scaup, are understudied hosts for these parasites.
• Declining populations of greater and lesser scaup in North America necessitate research into factors affecting their health.

Purpose of the Study:

• To explore haemosporidian diversity and host associations in diving ducks.
• To identify factors influencing haemosporidian infections in greater (Aythya marila) and lesser scaup (Aythya affinis).
• To fill a geographical sampling gap for haemosporidians along a key North American migratory route.

Main Methods:

• Molecular detection of haemosporidians in 82 hunter-donated waterfowl from 8 species.
• Phylogenetic and statistical analyses to determine parasite diversity and host associations.
• Survey conducted in Green Bay, Wisconsin, from 2019 to 2021.

Main Results:

• Detected 14 unique haemosporidian lineages, including 4 novel ones, across all 8 host species.
• Lesser scaup exhibited more diverse haemosporidian communities than greater scaup.
• Female lesser scaup had the highest infection prevalence; no effect of host age or sampling year.

Conclusions:

• Species and sex are crucial factors influencing haemosporidian infection risk in waterfowl.
• Findings contribute to understanding parasite evolution, ecology, and waterfowl conservation.
• Results highlight the importance of monitoring parasites in wild bird populations.