Diversity, distribution, and methodological considerations of haemosporidian infections among Galliformes in Alaska

Abstract

Using samples spanning 10-degrees of latitude in Alaska, we provide the first comparative assessment of avian haemosporidia distribution of Arctic Alaska with subarctic host populations for four species of grouse and three species of ptarmigan (Galliformes). We found a high overall prevalence for at least one haemospordian genus (88%; N = 351/400), with spruce grouse (Canachites canadensis) showing the highest prevalence (100%; N = 54/54). Haemoproteus and Plasmodium lineages were only observed within grouse, while Leucocytozoon species were found within both grouse and ptarmigan. Further, different Leucocytozoon lineages were obtained from blood and tissue samples from the same individual, potentially due to the differential timing and duration of blood and tissue stages. Using different primer sets, we were able to identify different Leucocytozoon lineages within 55% (N = 44/80) of sequenced individuals, thereby detecting coinfections that may have otherwise gone undetected. The commonly used Haemoproteus/Plasmodium primers amplified Leucocytozoon for 90% (N = 103/115) of the products sequenced, highlighting the potential value of alternate primers to identify intra-genus coinfections and the importance of obtaining sequence information rather than relying solely on PCR amplification to assess parasite diversity. Overall, this dataset provides baseline information on parasite lineage distributions to assess the range expansion associated with climate change into Arctic regions and underscores methodological considerations for future studies.

Keywords: Avian haemosporidia; Grouse; Parasite diversity; Ptarmigan.

Graphical abstract

Fig. 1

Map of sampling locations in Alaska. Circles show the number of samples for each grouse and ptarmigan species collected at each study site. Description of precise locations located in supplementary materials (Table A). Free vector and raster map from Natural Earth (https://www.naturalearthdata.com).

Fig. 2

Classification tree displaying the determining variables displaying the highest significance of association with host infection status. Y indicates positive infection status, and N indicates negative infection status. Each node represents the number of positive and negative infections associated with each determining variable(s), where the black fill represents the proportion of positive infections associated with each variable or combination of variables. The variable bio5 is the maximum temperature of the warmest month.

Fig. 3

Location prevalence for individuals testing positive (P) and negative (N) for all three genera of haemosporidian parasites. Regionality is defined as follows: Arctic: Arctic Coastal Plain, Brooks Range, Finger Mountain. Interior: Eagle Summit, Minto, Galena, Denali Highway, Taylor Highway, Fairbanks Area, Farewell. Southcentral: Palmer, Eureka. Southcoastal: Lake Clark National Park and Preserve, Kenai, Thompson Pass. Southeast: Lemesurier Island.

Fig. 4

Hatch year (HY) ruffed grouse, rock ptarmigan, willow ptarmigan, spruce grouse, sharp tailed grouse, and white-tailed ptarmigan individuals testing positive for at least one parasite genus. This figure aggregates all years sampled for 27 individuals. Hatch year individuals are less than three months old at the time of sampling, with the exception of individuals sampled in January and March where age is less than 10 months old. P = positive, N = negative.