Haemosporidian parasite diversity and prevalence in the songbird genusJuncoacross Central and North America

Abstract

The evolution of host–parasite interactions as host lineages colonize new geographic regions and diversify over evolutionary time is poorly understood. To assess whether haemosporidian parasite diversity has changed during the diversification of an avian host, we surveyed the diversity and prevalence of blood parasite lineages (genera Plasmodium, Haemoproteus, and Leucocytozoon) across the range of the songbird genus Junco, which has diversified recently as it recolonized North America following the last glacial maximum ~18,000 years ago. We report the diversity and prevalence of parasites in junco taxa sampled from Costa Rica to Canada, and examine the influence of local avian species richness in the prevalence and diversity of parasites in junco samples. We screened for parasites in each individual by sequencing a fragment of their cytochrome b gene, identifying the different lineages, and quantifying the prevalence per junco taxon and locality. Of 304 juncos sampled, 178 tested positive for 1 or more parasite genera (58.5% overall prevalence). We found high parasite diversity in genera Haemoproteus and Leucocytozoon and much lower diversity in Plasmodium. Among the 63 parasite lineages detected, 32 of which have not been previously described, we found generalist lineages with widespread but low prevalence in Junco, but also some that appear to have remained specialized on this genus as it diversified across North America over thousands of years. Our results suggest a range of parasitic strategies, ranging from specialized to generalist lineages within single parasite genera.

Determinants of spring migration departure dates in a New World sparrow: Weather variables reign supreme

“…In this study, we used overwintering migratory Dark‐eyed Juncos ( Junco hyemalis ; hereafter “junco”) to test the hypothesis that physiological state and haemosporidian infection interact with weather conditions and migration distance to shape spring migratory departure timing. Haemosporidia have been well‐characterized in Dark‐eyed juncos, with chronic (i.e., long‐term) infections detected in wintering and breeding populations (Becker et al., 2019, 2020; Deviche et al., 2001; Ferrer, 2022; Martínez‐Renau et al., 2022; Slowinski et al., 2018; Talbott et al., 2022). We used stable isotopes of hydrogen from feathers to estimate the distance to breeding grounds for each individual (Bowen et al., 2014; Hobson, 1999; Hobson et al., 2012; Rubenstein & Hobson, 2004; Wunder, 2010) and the Motus Wildlife Tracking System to determine departure date (Taylor et al., 2017).…”

Physiological impacts of chronic and experimental Plasmodium infection on breeding-condition male songbirds

“…To investigate the physiological impacts of parasitism in breeding-condition songbirds while disentangling variation attributable to phase of infection, we employed observational and experimental approaches in a North American migratory songbird, the dark-eyed junco ( J. h. hyemalis, hereafter ‘junco’) 37 . Plasmodium has been noted in many junco populations 38 – 41 , with prevalences up to approximately 71% 41 . Because only males of this species reliably show recrudescence in captivity in response to photoperiod stimuli (E.K., personal observation), we focused our study on male juncos.…”

Determinants of spring migration departure dates in a New World sparrow: weather variables reign supreme

“…In this study, we used overwintering migratory Dark-eyed Juncos ( Junco hyemalis hyemalis; hereafter “junco”) to test the hypothesis that physiological state and haemosporidian infection interact with weather conditions and migration distance to shape spring migratory departure timing. Haemosporidia have been well characterized in Dark-eyed juncos, with chronic (i.e., long-term) infections detected in wintering and breeding populations (Becker et al 2020; Slowinski et al 2018; Talbott et al 2022; Martínez-Renau et al 2022; Becker et al 2019; Deviche, Greiner, and Manteca 2001; Ferrer 2022). We used stable isotopes of hydrogen from feathers to estimate the distance to breeding grounds for each individual (Bowen et al, 2014; Hobson, 1999; Hobson et al, 2012; Rubenstein and Hobson, 2004; Wunder, 2010) and the Motus Wildlife Tracking System to determine departure date (Taylor et al, 2017).…”