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Title Parasite dynamics in North American monarchs predicted by host density and seasonal migratory culling
Author Ania A. Majewska, Andrew K. Davis, Sonia Altizer, Jacobus C. de Roode
Date 2021-08-01
Description Average infection prevalence was four times higher in western compared to eastern subpopulations. In eastern North America, the proportion of infected monarchs increased three-fold since the mid-2000s. In the western region, the proportion of infected monarchs declined sharply from 2000-2015, and increased thereafter. For both eastern and western subpopulations, years with greater summer adult abundance predicted greater infection prevalence, indicating that transmission increases with host breeding density. Environmental variables (temperature and NDVI) were not associated with changes in infected adults. We found evidence for migratory culling of infected butterflies, based on declines in parasitism during fall migration. We estimated that tens of millions fewer monarchs reach overwintering sites in Mexico as a result of OE, highlighting the need to consider the parasite as a potential threat to the monarch population
Keywords animal migration, Danaus plexippus, environmental change, milkweed butterfly, neogregarine, Ophryocystis elektroscirrha, population abundance, seasonality
URL https://besjournals-onlinelibrary-wiley-com.proxy.library.cornell.edu/doi/epdf/10.1111/1365-2656.13678
Photograph 1
ID 8123