The microsporidian Nosema is a common honeybee pathogen which enters the adult bee orally and multiplies in its gut, imposing a metabolic demand on its host. The newly discovered Nosema ceranae, given its relatively new association with the European honeybee, is likely to be particularly severe in this regard. We therefore hypothesized that N. ceranae exerts a significant effect on the feeding behavior of infected bees. Results from our experiments support this idea, revealing that infected bees are more responsive to sucrose and are less inclined to share this food with other bees, suggesting that they have a higher hunger level. We argue that increased hunger in the host is a general physiological effect of a number of pathogenic infections and due to its effect on host behavior could act as a mechanism by which the host and the pathogen can influence the transmission rates of an infection. Behavioral mechanisms, mediated by physiology could therefore be in the frontline of any arms race between a host and its pathogen.

Eroding permafrost coasts are likely indicators and integrators of changes in the Arctic System as they are susceptible to the combined effects of declining sea ice extent, increases in open water duration, more frequent and impactful storms, sea-level rise, and warming permafrost. However, few observation sites in the Arctic have yet to link decadal-scale erosion rates with changing environmental conditions due to temporal data gaps. This study increases the temporal fidelity of coastal permafrost bluff observations using near-annual high spatial resolution (<1 m) satellite imagery acquired between 2008-2017 for a 9 km segment of coastline at Drew Point, Beaufort Sea coast, Alaska. Our results show that mean annual erosion for the 2007-2016 decade was 17.2 m yr −1 , which is 2.5 times faster than historic rates, indicating that bluff erosion at this site is likely responding to changes in the Arctic System. In spite of a sustained increase in decadal-scale mean annual erosion rates, mean open water season erosion varied from 6.7 m yr −1 in 2010 to more than 22.0 m yr −1 in 2007, 2012, and 2016. This variability provided a range of coastal responses through which we explored the different roles of potential environmental drivers. The lack of significant correlations between mean open water season erosion and the environmental variables compiled in this study indicates that we may not be adequately capturing the environmental forcing factors, that the system is conditioned by long-term transient effects or extreme weather events rather than annual variability, or that other not yet considered factors may be responsible for the increased erosion occurring at Drew Point. Our results highlight an increase in erosion at Drew Point in the 21st century as well as the complexities associated with unraveling the factors responsible for changing coastal permafrost bluffs in the Arctic.

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